System Requirements
NiFi Registry has the following minimum system requirements:
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Requires Java Development Kit (JDK) 8, newer than 1.8.0_45
When running Registry with only a JRE you may encounter the following error as Flyway (database migration tool) attempts to utilize a resource from the JDK:java.lang.RuntimeException: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Validate failed: Detected failed migration to version 1.3 (DropBucketItemNameUniqueness)
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Supported Operating Systems:
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Linux
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Unix
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Mac OS X
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Supported Web Browsers:
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Google Chrome: Current & (Current - 1)
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Mozilla FireFox: Current & (Current - 1)
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Safari: Current & (Current - 1)
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How to install and start NiFi Registry
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Linux/Unix/OS X
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Decompress and untar into desired installation directory
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Make any desired edits in files found under
<installdir>/conf -
From the
<installdir>/bindirectory, execute the following commands by typing./nifi-registry.sh <command>:-
start: starts NiFi Registry in the background -
stop: stops NiFi Registry that is running in the background -
status: provides the current status of NiFi Registry -
run: runs NiFi Registry in the foreground and waits for a Ctrl-C to initiate shutdown of NiFi Registry -
install: installs NiFi Registry as a service that can then be controlled via-
service nifi-registry start -
service nifi-registry stop -
service nifi-registry status
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When NiFi Registry first starts up, the following directories are created:
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flow_storage -
database -
work -
logs -
run
See the System Properties section of this guide for more information about NiFi Registry configuration files.
Recommended Antivirus Exclusions
Antivirus software can take a long time to scan large directories and the numerous files within them. Additionally, if the antivirus software locks files or directories during a scan, those resources are unavailable to NiFi Registry processes, causing latency or unavailability of these resources in a NiFi Registry instance. To prevent these performance and reliability issues from occurring, it is highly recommended to configure your antivirus software to skip scans on the following NiFi Registry directories:
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database -
extension_bundles -
flow_storage -
logs
| The directories listed are generated at startup for a default NiFi Registry installation. Consider your configuration when determining directories to exclude during antivirus scans. For example, if an external database has been setup or if a different flow storage directory is specified in your configuration. |
Security Configuration
NiFi Registry provides several different configuration options for security purposes. The most important properties are those under the "security properties" heading in the nifi-registry.properties file. In order to run securely, the following properties must be set:
| Property Name | Description |
|---|---|
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Filename of the Keystore that contains the server’s private key. |
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The type of Keystore. Must be |
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The password for the Keystore. |
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The password for the certificate in the Keystore. If not set, the value of |
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Filename of the Truststore that will be used to authorize those connecting to NiFi Registry. A secured instance with no Truststore will refuse all incoming connections. |
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The type of the Truststore. Must be |
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The password for the Truststore. |
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This specifies that connecting clients must authenticate with a client cert. Setting this to |
Once the above properties have been configured, we can enable the User Interface to be accessed over HTTPS instead of HTTP. This is accomplished
by setting the nifi.registry.web.https.host and nifi.registry.web.https.port properties. The nifi.registry.web.https.host property indicates which hostname the server
should run on. If it is desired that the HTTPS interface be accessible from all network interfaces, a value of 0.0.0.0 should be used for nifi.registry.web.https.host.
It is important when enabling HTTPS that the nifi.registry.web.http.port property be unset.
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TLS Cipher Suites
The Java Runtime Environment provides the ability to specify custom TLS cipher suites to be used by servers when accepting client connections. See here for more information. To use this feature for the NiFi web service, the following NiFi properties may be set:
| Property Name | Description |
|---|---|
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Set of ciphers that are available to be used by incoming client connections. Replaces system defaults if set. |
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Set of ciphers that must not be used by incoming client connections. Filters available ciphers if set. |
Each property should take the form of a comma-separated list of common cipher names as specified
here. Regular expressions
(for example ^.*GCM_SHA256$) may also be specified.
The semantics match the use of the following Jetty APIs:
User Authentication
A secured instance of NiFi Registry cannot be accessed anonymously, so a method of user authentication must be configured.
| NiFi Registry does not perform user authentication over HTTP. Using HTTP, all users will have full permissions. |
Any secured instance of NiFi Registry supports authentication via client certificates that are trusted by the NiFi Registry’s SSL Context Truststore. Alternatively, a secured NiFi Registry can be configured to authenticate users via username/password.
Username/password authentication is performed by an 'Identity Provider'. The Identity Provider is a pluggable mechanism for authenticating users via their username/password. Which Identity Provider to use is configured in the nifi-registry.properties file. Currently NiFi Registry offers Identity Providers for LDAP and Kerberos.
Identity Providers are configured using two properties in the nifi-registry.properties file:
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The
nifi.registry.security.identity.providers.configuration.fileproperty specifies the configuration file where identity providers are defined. By default, the identity-providers.xml file located in the root installationconfdirectory is selected. -
The
nifi.registry.security.identity.providerproperty indicates which of the configured identity providers in the identity-providers.xml file to use. By default, this property is not configured meaning that username/password must be explicitly enabled.
| NiFi Registry can only be configured to use one Identity Provider at a given time. |
Lightweight Directory Access Protocol (LDAP)
Below is an example and description of configuring a Identity Provider that integrates with a Directory Server to authenticate users.
Set the following in nifi-registry.properties to enable LDAP username/password authentication:
nifi.registry.security.identity.provider=ldap-identity-provider
Modify identity-providers.xml to enable the ldap-identity-provider. Here is the sample provided in the file:
<provider>
<identifier>ldap-identity-provider</identifier>
<class>org.apache.nifi.registry.security.ldap.LdapIdentityProvider</class>
<property name="Authentication Strategy">START_TLS</property>
<property name="Manager DN"></property>
<property name="Manager Password"></property>
<property name="TLS - Keystore"></property>
<property name="TLS - Keystore Password"></property>
<property name="TLS - Keystore Type"></property>
<property name="TLS - Truststore"></property>
<property name="TLS - Truststore Password"></property>
<property name="TLS - Truststore Type"></property>
<property name="TLS - Client Auth"></property>
<property name="TLS - Protocol"></property>
<property name="TLS - Shutdown Gracefully"></property>
<property name="Referral Strategy">FOLLOW</property>
<property name="Connect Timeout">10 secs</property>
<property name="Read Timeout">10 secs</property>
<property name="Url"></property>
<property name="User Search Base"></property>
<property name="User Search Filter"></property>
<property name="Identity Strategy">USE_DN</property>
<property name="Authentication Expiration">12 hours</property>
</provider>
The ldap-identity-provider has the following properties:
| Property Name | Description |
|---|---|
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How the connection to the LDAP server is authenticated. Possible values are |
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The DN of the manager that is used to bind to the LDAP server to search for users. |
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The password of the manager that is used to bind to the LDAP server to search for users. |
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Path to the Keystore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Password for the Keystore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Type of the Keystore that is used when connecting to LDAP using LDAPS or START_TLS (i.e. |
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Path to the Truststore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Password for the Truststore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Type of the Truststore that is used when connecting to LDAP using LDAPS or START_TLS (i.e. |
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Client authentication policy when connecting to LDAP using LDAPS or START_TLS. Possible values are |
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Protocol to use when connecting to LDAP using LDAPS or START_TLS. (i.e. |
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Specifies whether the TLS should be shut down gracefully before the target context is closed. Defaults to |
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Strategy for handling referrals. Possible values are |
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Duration of connect timeout. (i.e. |
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Duration of read timeout. (i.e. |
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Space-separated list of URLs of the LDAP servers (i.e. |
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Base DN for searching for users (i.e. |
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Filter for searching for users against the |
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Strategy to identify users. Possible values are |
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The duration of how long the user authentication is valid for. If the user never logs out, they will be required to log back in following this duration. |
Kerberos
Below is an example and description of configuring an Identity Provider that integrates with a Kerberos Key Distribution Center (KDC) to authenticate users.
Set the following in nifi-registry.properties to enable Kerberos username/password authentication:
nifi.registry.security.user.identity.provider=kerberos-identity-provider
Modify identity-providers.xml to enable the kerberos-identity-provider. Here is the sample provided in the file:
<provider>
<identifier>kerberos-identity-provider</identifier>
<class>org.apache.nifi.registry.web.security.authentication.kerberos.KerberosIdentityProvider</class>
<property name="Default Realm">NIFI.APACHE.ORG</property>
<property name="Authentication Expiration">12 hours</property>
<property name="Enable Debug">false</property>
</provider>
The kerberos-identity-provider has the following properties:
| Property Name | Description |
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Default realm to provide when user enters incomplete user principal (i.e. |
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The duration for which the user authentication is valid. If the user never logs out, they will be required to log back in following this duration. |
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Enables debug logging output for the SunJaasKerberosClient used internally by the KerberosIdentityProvider. By default, this is set to |
See also Kerberos Service to allow single sign-on access via client Kerberos tickets.
Authorization
After you have configured NiFi Registry to run securely and with an authentication mechanism, you must configure who has access to the system and their level of access. This is done by defining policies that give users and groups permissions to perform a particular action. These policies are defined in an 'authorizer'.
Authorizer Configuration
An 'authorizer' manages known users and their access policies. Authorizers are configured using two properties in the nifi-registry.properties file:
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The
nifi.registry.security.authorizers.configuration.fileproperty specifies the configuration file where authorizers are defined. By default, the authorizers.xml file located in the root installation conf directory is selected. -
The
nifi.registry.security.authorizerproperty indicates which of the configured authorizers in the authorizers.xml file to use.
Authorizers.xml Setup
The authorizers.xml file is used to define and configure available authorizers.
StandardManagedAuthorizer
The default Authorizer is the StandardManagedAuthorizer, however, you can develop additional Authorizers as extensions. The StandardManagedAuthorizer has the following properties:
| Property Name | Description |
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The identifier for an Access Policy Provider defined above. |
The managed authorizer is comprised of a UserGroupProvider and a AccessPolicyProvider. The users, group, and access policies will be loaded and optionally configured through these providers. The managed authorizer will make all access decisions based on these provided users, groups, and access policies.
During startup there is a check to ensure that there are no two users/groups with the same identity/name. This check is executed regardless of the configured implementation. This is necessary because this is how users/groups are identified and authorized during access decisions.
UserGroupProvider
FileUserGroupProvider
The default UserGroupProvider is the FileUserGroupProvider, however, you can develop additional UserGroupProviders as extensions. The FileUserGroupProvider has the following properties:
| Property Name | Description |
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The file where the FileUserGroupProvider stores users and groups.
By default, users.xml in the |
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The identity of a user or system to seed an empty Users File.
Multiple Initial User Identity properties can be specified, but the name of each property must be unique, for example: |
| Initial User Identities are only created if the specified Users File is missing or empty during NiFi Registry startup. Changes to the configured Initial Users Identities will not take effect if the Users File is populated. |
LdapUserGroupProvider
Another option for the UserGroupProvider is the LdapUserGroupProvider. By default, this option is commented out but can be configured in lieu of the FileUserGroupProvider. This will sync users and groups from a directory server and will present them in NiFi Registry UI in read only form. The LdapUserGroupProvider has the following properties:
| Property Name | Description |
|---|---|
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How the connection to the LDAP server is authenticated. Possible values are |
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The DN of the manager that is used to bind to the LDAP server to search for users. |
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The password of the manager that is used to bind to the LDAP server to search for users. |
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Path to the Keystore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Password for the Keystore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Type of the Keystore that is used when connecting to LDAP using LDAPS or START_TLS (i.e. |
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Path to the Truststore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Password for the Truststore that is used when connecting to LDAP using LDAPS or START_TLS. |
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Type of the Truststore that is used when connecting to LDAP using LDAPS or START_TLS (i.e. |
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Client authentication policy when connecting to LDAP using LDAPS or START_TLS. Possible values are |
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Protocol to use when connecting to LDAP using LDAPS or START_TLS. (i.e. |
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Specifies whether the TLS should be shut down gracefully before the target context is closed. Defaults to |
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Strategy for handling referrals. Possible values are |
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Duration of connect timeout. (i.e. |
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Duration of read timeout. (i.e. |
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Space-separated list of URLs of the LDAP servers (i.e. |
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Sets the page size when retrieving users and groups. If not specified, no paging is performed. |
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Duration of time between syncing users and groups. (i.e. |
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Sets whether group membership decisions are case sensitive. When a user or group is inferred (by not specifying or user or group search base or user identity attribute or group name attribute) case sensitivity is enforced since the value to use for the user identity or group name would be ambiguous. Defaults to false. |
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Base DN for searching for users (i.e. |
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Object class for identifying users (i.e. |
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Search scope for searching users ( |
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Filter for searching for users against the |
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Attribute to use to extract user identity (i.e. |
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Attribute to use to define group membership (i.e. |
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If blank, the value of the attribute defined in |
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Base DN for searching for groups (i.e. |
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Object class for identifying groups (i.e. |
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Search scope for searching groups ( |
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Filter for searching for groups against the |
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Attribute to use to extract group name (i.e. |
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Attribute to use to define group membership (i.e. |
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If blank, the value of the attribute defined in |
Composite Implementations
Another option for the UserGroupProvider are composite implementations. This means that multiple sources/implementations can be configured and composed. For instance, an admin can configure users/groups to be loaded from a file and a directory server. There are two composite implementations, one that supports multiple UserGroupProviders and one that supports multiple UserGroupProviders and a single configurable UserGroupProvider.
The CompositeUserGroupProvider will provide support for retrieving users and groups from multiple sources. The CompositeUserGroupProvider has the following properties:
| Property Name | Description |
|---|---|
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The identifier of user group providers to load from. The name of each property must be unique, for example: |
The CompositeConfigurableUserGroupProvider will provide support for retrieving users and groups from multiple sources. Additionally, a single configurable user group provider is required. Users from the configurable user group provider are configurable, however users loaded from one of the User Group Provider [unique key] will not be. The CompositeConfigurableUserGroupProvider has the following properties:
| Property Name | Description |
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A configurable user group provider. |
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The identifier of user group providers to load from. The name of each property must be unique, for example: |
AccessPolicyProvider
After you have configured a UserGroupProvider, you must configure an AccessPolicyProvider that will control Access Policies for the identities in the UserGroupProvider.
FileAccessPolicyProvider
The default AccessPolicyProvider is the FileAccessPolicyProvider, however, you can develop additional AccessPolicyProvider as extensions. The FileAccessPolicyProvider has the following properties:
| Property Name | Description |
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The identifier for an User Group Provider defined above that will be used to access users and groups for use in the managed access policies. |
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The file where the FileAccessPolicyProvider will store policies. By default, authorizations.xml in the |
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The identity of an initial admin user that will be granted access to the UI and given the ability to create additional users, groups, and policies. For example, a certificate DN, LDAP identity, or Kerberos principal. |
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The identity of a NiFi instance/node that will be accessing this registry. Each NiFi Identity will be granted permission to proxy user requests, as well as read any bucket to perform synchronization status checks. |
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The name of the group, whose members are NiFi instance/node identities, that will be accessing this registry. The members of this group will be granted permission to proxy user requests, as well as read any bucket to perform synchronization checks. |
| The identities configured in the Initial Admin Identity and NiFi Identity properties must be available in the configured User Group Provider. Initial Admin Identity and NiFi Identity properties are only read by NiFi Registry when the Authorizations File is missing or empty on startup in order to seed the initial Authorizations File. Changes to the configured Initial Admin Identity and NiFi Identities will not take effect if the Authorizations File is populated. |
Initial Admin Identity (New NiFi Registry Instance)
If you are setting up a secured NiFi Registry instance for the first time, you must manually designate an “Initial Admin Identity” in the authorizers.xml file. This initial admin user is granted access to the UI and given the ability to create additional users, groups, and policies. The value of this property could be a certificate DN , LDAP identity (DN or username), or a Kerberos principal. If you are the NiFi Registry administrator, add yourself as the “Initial Admin Identity”.
After you have edited and saved the authorizers.xml file, restart NiFi Registry. The users.xml and authorizations.xml files will be created, and the “Initial Admin Identity” user and administrative policies are added during start up. Once NiFi Registry starts, the “Initial Admin Identity” user is able to access the UI and begin managing users, groups, and policies.
| If initial NiFi identities are not provided, they can be added through the UI at a later time by first creating a user for the given NiFi identity, and then giving that user both Proxy permissions and permission to Buckets/READ in order to read all buckets. |
Some common use cases are described below.
File-based (LDAP Authentication)
Here is an example certificate DN entry using the name John Smith:
<authorizers>
<userGroupProvider>
<identifier>file-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileUserGroupProvider</class>
<property name="Users File">./conf/users.xml</property>
<property name="Legacy Authorized Users File"></property>
<property name="Initial User Identity 1">cn=John Smith,ou=people,dc=example,dc=com</property>
</userGroupProvider>
<accessPolicyProvider>
<identifier>file-access-policy-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileAccessPolicyProvider</class>
<property name="User Group Provider">file-user-group-provider</property>
<property name="Authorizations File">./conf/authorizations.xml</property>
<property name="Initial Admin Identity">cn=John Smith,ou=people,dc=example,dc=com</property
<property name="NiFi Identity 1"></property>
</accessPolicyProvider>
<authorizer>
<identifier>managed-authorizer</identifier>
<class>org.apache.nifi.registry.security.authorization.StandardManagedAuthorizer</class>
<property name="Access Policy Provider">file-access-policy-provider</property>
</authorizer>
</authorizers>
File-based (Kerberos Authentication)
Here is an example Kerberos entry using the name John Smith and realm NIFI.APACHE.ORG:
<authorizers>
<userGroupProvider>
<identifier>file-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileUserGroupProvider</class>
<property name="Users File">./conf/users.xml</property>
<property name="Initial User Identity 1">johnsmith@NIFI.APACHE.ORG</property>
</userGroupProvider>
<accessPolicyProvider>
<identifier>file-access-policy-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileAccessPolicyProvider</class>
<property name="User Group Provider">file-user-group-provider</property>
<property name="Authorizations File">./conf/authorizations.xml</property>
<property name="Initial Admin Identity">johnsmith@NIFI.APACHE.ORG</property>
<property name="NiFi Identity 1"></property>
</accessPolicyProvider>
<authorizer>
<identifier>managed-authorizer</identifier>
<class>org.apache.nifi.registry.security.authorization.StandardManagedAuthorizer</class>
<property name="Access Policy Provider">file-access-policy-provider</property>
</authorizer>
</authorizers>
LDAP-based Users/Groups Referencing User DN
Here is an example loading users and groups from LDAP. Group membership will be driven through the member attribute of each group. Authorization will still use file-based access policies.
Given the following LDAP entries exist:
dn: cn=User 1,ou=users,o=nifi objectClass: organizationalPerson objectClass: person objectClass: inetOrgPerson objectClass: top cn: User 1 sn: User1 uid: user1 dn: cn=User 2,ou=users,o=nifi objectClass: organizationalPerson objectClass: person objectClass: inetOrgPerson objectClass: top cn: User 2 sn: User2 uid: user2 dn: cn=users,ou=groups,o=nifi objectClass: groupOfNames objectClass: top cn: users member: cn=User 1,ou=users,o=nifi member: cn=User 2,ou=users,o=nifi
An Authorizer using an LdapUserGroupProvider would be configured as:
<authorizers>
<userGroupProvider>
<identifier>ldap-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.ldap.tenants.LdapUserGroupProvider</class>
<property name="Authentication Strategy">ANONYMOUS</property>
<property name="Manager DN"></property>
<property name="Manager Password"></property>
<property name="TLS - Keystore"></property>
<property name="TLS - Keystore Password"></property>
<property name="TLS - Keystore Type"></property>
<property name="TLS - Truststore"></property>
<property name="TLS - Truststore Password"></property>
<property name="TLS - Truststore Type"></property>
<property name="TLS - Client Auth"></property>
<property name="TLS - Protocol"></property>
<property name="TLS - Shutdown Gracefully"></property>
<property name="Referral Strategy">FOLLOW</property>
<property name="Connect Timeout">10 secs</property>
<property name="Read Timeout">10 secs</property>
<property name="Url">ldap://localhost:10389</property>
<property name="Page Size"></property>
<property name="Sync Interval">30 mins</property>
<property name="Group Membership - Enforce Case Sensitivity">false</property>
<property name="User Search Base">ou=users,o=nifi</property>
<property name="User Object Class">person</property>
<property name="User Search Scope">ONE_LEVEL</property>
<property name="User Search Filter"></property>
<property name="User Identity Attribute">cn</property>
<property name="User Group Name Attribute"></property>
<property name="User Group Name Attribute - Referenced Group Attribute"></property>
<property name="Group Search Base">ou=groups,o=nifi</property>
<property name="Group Object Class">groupOfNames</property>
<property name="Group Search Scope">ONE_LEVEL</property>
<property name="Group Search Filter"></property>
<property name="Group Name Attribute">cn</property>
<property name="Group Member Attribute">member</property>
<property name="Group Member Attribute - Referenced User Attribute"></property>
</userGroupProvider>
<accessPolicyProvider>
<identifier>file-access-policy-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileAccessPolicyProvider</class>
<property name="User Group Provider">ldap-user-group-provider</property>
<property name="Authorizations File">./conf/authorizations.xml</property>
<property name="Initial Admin Identity">User 1</property>
<property name="NiFi Identity 1"></property>
</accessPolicyProvider>
<authorizer>
<identifier>managed-authorizer</identifier>
<class>org.apache.nifi.registry.security.authorization.StandardManagedAuthorizer</class>
<property name="Access Policy Provider">file-access-policy-provider</property>
</authorizer>
</authorizers>
The Initial Admin Identity value would have loaded from the cn of the User 1 entry based on the User Identity Attribute value.
Composite - File and LDAP-based Users/Groups
Here is an example composite implementation loading users and groups from LDAP and a local file. Group membership will be driven through the member attribute of each group. The users from LDAP will be read only while the users loaded from the file will be configurable in UI.
<authorizers>
<userGroupProvider>
<identifier>file-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileUserGroupProvider</class>
<property name="Users File">./conf/users.xml</property>
<property name="Initial User Identity 1">cn=nifi-node1,ou=servers,dc=example,dc=com</property>
<property name="Initial User Identity 2">cn=nifi-node2,ou=servers,dc=example,dc=com</property>
</userGroupProvider>
<userGroupProvider>
<identifier>ldap-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.ldap.tenants.LdapUserGroupProvider</class>
<property name="Authentication Strategy">ANONYMOUS</property>
<property name="Manager DN"></property>
<property name="Manager Password"></property>
<property name="TLS - Keystore"></property>
<property name="TLS - Keystore Password"></property>
<property name="TLS - Keystore Type"></property>
<property name="TLS - Truststore"></property>
<property name="TLS - Truststore Password"></property>
<property name="TLS - Truststore Type"></property>
<property name="TLS - Client Auth"></property>
<property name="TLS - Protocol"></property>
<property name="TLS - Shutdown Gracefully"></property>
<property name="Referral Strategy">FOLLOW</property>
<property name="Connect Timeout">10 secs</property>
<property name="Read Timeout">10 secs</property>
<property name="Url">ldap://localhost:10389</property>
<property name="Page Size"></property>
<property name="Sync Interval">30 mins</property>
<property name="Group Membership - Enforce Case Sensitivity">false</property>
<property name="User Search Base">ou=users,o=nifi</property>
<property name="User Object Class">person</property>
<property name="User Search Scope">ONE_LEVEL</property>
<property name="User Search Filter"></property>
<property name="User Identity Attribute">cn</property>
<property name="User Group Name Attribute"></property>
<property name="User Group Name Attribute - Referenced Group Attribute"></property>
<property name="Group Search Base">ou=groups,o=nifi</property>
<property name="Group Object Class">groupOfNames</property>
<property name="Group Search Scope">ONE_LEVEL</property>
<property name="Group Search Filter"></property>
<property name="Group Name Attribute">cn</property>
<property name="Group Member Attribute">member</property>
<property name="Group Member Attribute - Referenced User Attribute"></property>
</userGroupProvider>
<userGroupProvider>
<identifier>composite-user-group-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.CompositeUserGroupProvider</class>
<property name="User Group Provider 1">file-user-group-provider</property>
<property name="User Group Provider 2">ldap-user-group-provider</property>
</userGroupProvider>
<accessPolicyProvider>
<identifier>file-access-policy-provider</identifier>
<class>org.apache.nifi.registry.security.authorization.file.FileAccessPolicyProvider</class>
<property name="User Group Provider">composite-user-group-provider</property>
<property name="Authorizations File">./conf/authorizations.xml</property>
<property name="Initial Admin Identity">User 1/property>
<property name="NiFi Identity 1">cn=nifi-node1,ou=servers,dc=example,dc=com</property>
<property name="NiFi Identity 2">cn=nifi-node2,ou=servers,dc=example,dc=com</property>
</accessPolicyProvider>
<authorizer>
<identifier>managed-authorizer</identifier>
<class>org.apache.nifi.registry.security.authorization.StandardManagedAuthorizer</class>
<property name="Access Policy Provider">file-access-policy-provider</property>
</authorizer>
</authorizers>
In this example, the users and groups are loaded from LDAP but the servers are managed in a local file. The Initial Admin Identity value came
from an attribute in a LDAP entry based on the User Identity Attribute. The NiFi Identity values are established in the local file using the
Initial User Identity properties.
Access Policies
You can manage the ability for users and groups to view or modify NiFi Registry resources using 'access policies'. Access policies can be created to control access to buckets, as well as to grant special privileges to users for managing a NiFi Registry instance.
Bucket Policies
Bucket policies govern the following bucket level authorizations:
| Policy | Privilege | Resource Descriptor |
|---|---|---|
Read Bucket |
Allows users to read items in the bucket |
|
Write Bucket |
Allows users to write items to the bucket |
|
Delete Bucket |
Allows users to delete the bucket |
|
Special Privilege Policies
Special privilege policies govern the following system level authorizations:
| Policy | Privilege | Resource Descriptor |
|---|---|---|
Can Manage Buckets (Read) |
Allows users to read from all buckets |
|
Can Manage Buckets (Write) |
Allows users to write to all buckets |
|
Can Manage Buckets (Delete) |
Allows users to delete all buckets |
|
Can Manage Users (Read) |
Allows users to view users |
|
Can Manage Users (Write) |
Allows users to create and modify users |
|
Can Manage Users (Delete) |
Allows users to delete users |
|
Can Manage Policies (Read) |
Allows users to view policies |
|
Can Manage Policies (Write) |
Allows users to create and modify policies |
|
Can Manage Policies (Delete) |
Allows users to delete policies |
|
Can Proxy Requests (Read) |
Allows users to proxy read requests (GET) |
|
Can Proxy Requests (Write) |
Allows users to proxy write requests (POST, PUT, PATCH) |
|
Can Proxy Requests (Delete) |
Allows users to proxy delete requests (DELETE) |
|
View Swagger |
Allows users to access the self-hosted Swagger UI |
|
View Actuator |
Allows users to access the Spring Boot Actuator end-points |
|
Encrypted Passwords in Configuration Files
In order to facilitate the secure setup of NiFi Registry, you can use the encrypt-config command line utility to encrypt raw configuration values
that NiFi Registry decrypts in memory on startup. This extensible protection scheme transparently allows NiFi Registry to use raw values in operation,
while protecting them at rest. In the future, hardware security modules (HSM) and external secure storage mechanisms will be integrated, but for now,
an AES encryption provider is the default implementation.
If no administrator action is taken, the configuration values remain unencrypted.
The encrypt-config tool for NiFi Registry is implemented as an additional mode to the existing tool in the nifi-toolkit. The following sections
assume you have downloaded the binary for the nifi-toolkit.
|
Encrypt-Config Tool
The encrypt-config command line tool can be used to encrypt NiFi Registry configuration by invoking the tool with the following command:
./bin/encrypt-config --nifiRegistry [options]
You can use the following command line options with the encrypt-config tool:
-
-h,--helpShow usage information (this message) -
-v,--verboseSets verbose mode (default false) -
-p,--password <password>Protect the files using a password-derived key. If an argument is not provided to this flag, interactive mode will be triggered to prompt the user to enter the password. -
-k,--key <keyhex>Protect the files using a raw hexadecimal key. If an argument is not provided to this flag, interactive mode will be triggered to prompt the user to enter the key. -
--oldPassword <password>If the input files are already protected using a password-derived key, this specifies the old password so that the files can be unprotected before re-protecting. -
--oldKey <keyhex>If the input files are already protected using a key, this specifies the raw hexadecimal key so that the files can be unprotected before re-protecting. -
-b,--bootstrapConf <file>The bootstrap.conf file containing no root key or an existing root key. If a new password or key is specified (using-por-k) and no output bootstrap.conf file is specified, then this file will be overwritten to persist the new root key. -
-B,--outputBootstrapConf <file>The destination bootstrap.conf file to persist root key. If specified, the input bootstrap.conf will not be modified. -
-r,--nifiRegistryProperties <file>The nifi-registry.properties file containing unprotected config values, overwritten if no output file specified. -
-R,--outputNifiRegistryProperties <file>The destination nifi-registry.properties file containing protected config values. -
-a,--authorizersXml <file>The authorizers.xml file containing unprotected config values, overwritten if no output file specified. -
-A,--outputAuthorizersXml <file>The destination authorizers.xml file containing protected config values. -
-i,--identityProvidersXml <file>The identity-providers.xml file containing unprotected config values, overwritten if no output file specified. -
-I,--outputIdentityProvidersXml <file>The destination identity-providers.xml file containing protected config values. -
--decryptCan be used with-rto decrypt a previously encrypted NiFi Registry Properties file. Decrypted content is printed to STDOUT.
As an example of how the tool works, assume that you have installed the tool on a machine supporting 256-bit encryption and with the following existing values in the nifi-registry.properties file:
# security properties # nifi.registry.security.keystore=/path/to/keystore.jks nifi.registry.security.keystoreType=JKS nifi.registry.security.keystorePasswd=thisIsABadKeystorePassword nifi.registry.security.keyPasswd=thisIsABadKeyPassword nifi.registry.security.truststore= nifi.registry.security.truststoreType= nifi.registry.security.truststorePasswd=
Enter the following arguments when using the tool:
./bin/encrypt-config.sh --nifiRegistry \ -b bootstrap.conf \ -k 0123456789ABCDEFFEDCBA98765432100123456789ABCDEFFEDCBA9876543210 \ -r nifi-registry.properties
As a result, the nifi-registry.properties file is overwritten with protected properties and sibling encryption identifiers (aes/gcm/256, the currently supported algorithm):
# security properties # nifi.registry.security.keystore=/path/to/keystore.jks nifi.registry.security.keystoreType=JKS nifi.registry.security.keystorePasswd=oBjT92hIGRElIGOh||MZ6uYuWNBrOA6usq/Jt3DaD2e4otNirZDytac/w/KFe0HOkrJR03vcbo nifi.registry.security.keystorePasswd.protected=aes/gcm/256 nifi.registry.security.keyPasswd=ac/BaE35SL/esLiJ||+ULRvRLYdIDA2VqpE0eQXDEMjaLBMG2kbKOdOwBk/hGebDKlVg== nifi.registry.security.keyPasswd.protected=aes/gcm/256 nifi.registry.security.truststore= nifi.registry.security.truststoreType= nifi.registry.security.truststorePasswd=
When applied to identity-providers.xml or authorizers.xml, the property elements are updated with an encryption attribute. For example:
<!-- LDAP Provider --> <provider> <identifier>ldap-provider</identifier> <class>org.apache.nifi.registry.security.ldap.LdapProvider</class> <property name="Authentication Strategy">START_TLS</property> <property name="Manager DN">someuser</property> <property name="Manager Password" encryption="aes/gcm/128">q4r7WIgN0MaxdAKM||SGgdCTPGSFEcuH4RraMYEdeyVbOx93abdWTVSWvh1w+klA</property> <property name="TLS - Keystore">/path/to/keystore.jks</property> <property name="TLS - Keystore Password" encryption="aes/gcm/128">Uah59TWX+Ru5GY5p||B44RT/LJtC08QWA5ehQf01JxIpf0qSJUzug25UwkF5a50g</property> <property name="TLS - Keystore Type">JKS</property> ... </provider>
Additionally, the bootstrap.conf file is updated with the encryption key as follows:
# Root key in hexadecimal format for encrypted sensitive configuration values nifi.registry.bootstrap.sensitive.key=0123456789ABCDEFFEDCBA98765432100123456789ABCDEFFEDCBA9876543210
Sensitive configuration values are encrypted by the tool by default, however you can encrypt any additional properties, if desired.
To encrypt additional properties, specify them as comma-separated values in the nifi.registry.sensitive.props.additional.keys property.
If the nifi-registry.properties file already has valid protected values and you wish to protect additional values using the same root key already present in your bootstrap.conf, then run the tool without specifying a new key:
# bootstrap.conf already contains root key property # nifi-registy.properties has been updated for nifi.registry.sensitive.props.additional.keys=... ./bin/encrypt-config.sh --nifiRegistry -b bootstrap.conf -r nifi-registry.properties
Sensitive Property Key Migration
In order to change the key used to encrypt the sensitive values, provide the new key or password using the -k or -p flags as usual,
and provide the existing key or password using --old-key or --old-password respectively. This will allow the toolkit to decrypt the
existing values and re-encrypt them, and update bootstrap.conf with the new key. Only one of the key or password needs to be specified
for each phase (old vs. new), and any combination is sufficient:
-
old key → new key
-
old key → new password
-
old password → new key
-
old password → new password
Bootstrap Properties
The bootstrap.conf file in the conf directory allows users to configure settings for how NiFi Registry should be started. This includes parameters, such as the size of the Java Heap, what Java command to run, and Java System Properties.
Here, we will address the different properties that are made available in the file. Any changes to this file will take effect only after NiFi Registry has been stopped and restarted.
Property |
Description |
|
Specifies the fully qualified java command to run. By default, it is simply |
|
The username to run NiFi Registry as. For instance, if NiFi Registry should be run as the |
|
The lib directory to use for NiFi Registry. By default, this is set to |
|
The |
|
When NiFi Registry is instructed to shutdown, the Bootstrap will wait this number of seconds for the process to shutdown cleanly. At this amount of time, if the service is still running, the Bootstrap will |
|
Any number of JVM arguments can be passed to the NiFi Registry JVM when the process is started. These arguments are defined by adding properties to bootstrap.conf that begin with |
|
The root key (in hexadecimal format) for encrypted sensitive configuration values. When NiFi Registry is started, this root key is used to decrypt sensitive values from the nifi-registry.properties file into memory for later use. The Encrypt-Config Tool can be used to specify the root key, encrypt sensitive values in nifi-registry.properties and update bootstrap.conf. |
Proxy Configuration
When running Apache NiFi Registry behind a proxy there are a couple of key items to be aware of during deployment.
-
NiFi Registry is comprised of a number of web applications (web UI, web API, documentation), so the mapping needs to be configured for the root path. That way all context paths are passed through accordingly.
-
If NiFi Registry is running securely, any proxy needs to be authorized to proxy user requests. These can be configured in the NiFi Registry UI through the Users administration section, by selecting 'Proxy' for the given user. Once these permissions are in place, proxies can begin proxying user requests. The end user identity must be relayed in a HTTP header. For example, if the end user sent a request to the proxy, the proxy must authenticate the user. Following this the proxy can send the request to NiFi Registry. In this request an HTTP header should be added as follows.
X-ProxiedEntitiesChain: <end-user-identity>
If the proxy is configured to send to another proxy, the request to NiFi Registry from the second proxy should contain a header as follows.
X-ProxiedEntitiesChain: <end-user-identity><proxy-1-identity>
An example Apache proxy configuration that sets the required properties may look like the following. Complete proxy configuration is outside of the scope of this document. Please refer to the documentation of the proxy for guidance with your deployment environment and use case.
...
<Location "/my-nifi">
...
SSLEngine On
SSLCertificateFile /path/to/proxy/certificate.crt
SSLCertificateKeyFile /path/to/proxy/key.key
SSLCACertificateFile /path/to/ca/certificate.crt
SSLVerifyClient require
RequestHeader add X-ProxyScheme "https"
RequestHeader add X-ProxyHost "proxy-host"
RequestHeader add X-ProxyPort "443"
RequestHeader add X-ProxyContextPath "/my-nifi-registry"
RequestHeader add X-ProxiedEntitiesChain "<%{SSL_CLIENT_S_DN}>"
ProxyPass https://nifi-registry-host:8443
ProxyPassReverse https://nifi-registry-host:8443
...
</Location>
...
Kerberos Service
NiFi Registry can be configured to use Kerberos SPNEGO (or "Kerberos Service") for authentication. In this scenario, users will hit the REST endpoint /access/token/kerberos
and the server will respond with a 401 status code and the challenge response header WWW-Authenticate: Negotiate. This communicates to the browser to use the GSS-API
and load the user’s Kerberos ticket and provide it as a Base64-encoded header value in the subsequent request. It will be of the form Authorization: Negotiate YII….
NiFi Registry will attempt to validate this ticket with the KDC. If it is successful, the user’s principal will be returned as the identity, and the flow will follow
login/credential authentication, in that a JWT will be issued in the response to prevent the unnecessary overhead of Kerberos authentication on every subsequent request.
If the ticket cannot be validated, it will return with the appropriate error response code. The user will then be able to provide their Kerberos credentials to the login
form if the KerberosIdentityProvider has been configured. See Kerberos Identity Provider for more details.
NiFi Registry will only respond to Kerberos SPNEGO negotiation over an HTTPS connection, as unsecured requests are never authenticated.
See Kerberos Properties for complete documentation.
Notes
-
Kerberos is case-sensitive in many places and the error messages (or lack thereof) may not be sufficiently explanatory. Check the case sensitivity of the service principal in your configuration files. The convention is
HTTP/fully.qualified.domain@REALM. -
Browsers have varying levels of restriction when dealing with SPNEGO negotiations. Some will provide the local Kerberos ticket to any domain that requests it, while others whitelist the trusted domains. See Spring Security Kerberos - Reference Documentation: Appendix E. Configure browsers for SPNEGO Negotiation for common browsers.
-
Some browsers (legacy IE) do not support recent encryption algorithms such as AES, and are restricted to legacy algorithms (DES). This should be noted when generating keytabs.
-
The KDC must be configured and a service principal defined for NiFi and a keytab exported. Comprehensive instructions for Kerberos server configuration and administration are beyond the scope of this document (see MIT Kerberos Admin Guide), but an example is below.
-
Kerberos tickets may use AES encryption with keys up to 256-bits in length, and therefore unlimited strength encryption policies may be required for the Jave Runtime Environment (JRE) used for NiFi Registry when Kerberos SPNEGO is configured.
Adding a service principal for a server at nifi.nifi.apache.org and exporting the keytab from the KDC:
root@kdc:/etc/krb5kdc# kadmin.local Authenticating as principal admin/admin@NIFI.APACHE.ORG with password. kadmin.local: listprincs K/M@NIFI.APACHE.ORG admin/admin@NIFI.APACHE.ORG ... kadmin.local: addprinc -randkey HTTP/nifi.nifi.apache.org WARNING: no policy specified for HTTP/nifi.nifi.apache.org@NIFI.APACHE.ORG; defaulting to no policy Principal "HTTP/nifi.nifi.apache.org@NIFI.APACHE.ORG" created. kadmin.local: ktadd -k /http-nifi.keytab HTTP/nifi.nifi.apache.org Entry for principal HTTP/nifi.nifi.apache.org with kvno 2, encryption type des3-cbc-sha1 added to keytab WRFILE:/http-nifi.keytab. Entry for principal HTTP/nifi.nifi.apache.org with kvno 2, encryption type des-cbc-crc added to keytab WRFILE:/http-nifi.keytab. kadmin.local: listprincs HTTP/nifi.nifi.apache.org@NIFI.APACHE.ORG K/M@NIFI.APACHE.ORG admin/admin@NIFI.APACHE.ORG ... kadmin.local: q root@kdc:~# ll /http* -rw------- 1 root root 162 Mar 14 21:43 /http-nifi.keytab root@kdc:~#
System Properties
The nifi-registry.properties file in the conf directory is the main configuration file for controlling how NiFi Registry runs. This section
provides an overview of the properties in this file and includes some notes on how to configure it in a way that will make upgrading easier.
After making changes to this file, restart NiFi Registry in order for the changes to take effect.
| Values for periods of time and data sizes must include the unit of measure, for example "10 secs" or "10 MB", not simply "10". |
Web Properties
These properties pertain to the web-based User Interface.
Property |
Description |
|
This is the location of the web war directory. The default value is |
|
The HTTP host. It is blank by default. |
|
The HTTP port. The default value is |
|
The HTTPS host. It is blank by default. |
|
The HTTPS port. It is blank by default. When configuring NiFi Registry to run securely, this port should be configured. |
|
The space-separated list of application protocols supported when running with HTTPS enabled. The default value is The value can be set to The value can be set to |
|
The location of the Jetty working directory. The default value is |
|
The number of Jetty threads. The default value is |
Security Properties
These properties pertain to various security features in NiFi Registry. Many of these properties are covered in more detail in the Security Configuration section.
Property |
Description |
|
The full path and name of the keystore. It is blank by default. |
|
The keystore type. It is blank by default. |
|
The keystore password. It is blank by default. |
|
The key password. It is blank by default. |
|
The full path and name of the truststore. It is blank by default. |
|
The truststore type. It is blank by default. |
|
The truststore password. It is blank by default. |
|
This specifies that connecting clients must authenticate with a client cert. Setting this to |
|
This is the location of the file that specifies how authorizers are defined. The default value is |
|
Specifies which of the configured Authorizers in the authorizers.xml file to use. By default, it is set to |
|
This is the location of the file that specifies how username/password authentication is performed. This file is only considered if |
|
This indicates what type of identity provider to use. The default value is blank, can be set to the identifier from a provider in the file specified in |
Identity Mapping Properties
These properties can be utilized to normalize user identities. When implemented, identities authenticated by different identity providers (certificates, LDAP, Kerberos) are treated the same internally in NiFi Registry. As a result, duplicate users are avoided and user-specific configurations such as authorizations only need to be setup once per user.
The following examples demonstrate normalizing DNs from certificates and principals from Kerberos:
nifi.registry.security.identity.mapping.pattern.dn=^CN=(.*?), OU=(.*?), O=(.*?), L=(.*?), ST=(.*?), C=(.*?)$ nifi.registry.security.identity.mapping.value.dn=$1@$2 nifi.registry.security.identity.mapping.transform.dn=NONE nifi.registry.security.identity.mapping.pattern.kerb=^(.*?)/instance@(.*?)$ nifi.registry.security.identity.mapping.value.kerb=$1@$2 nifi.registry.security.identity.mapping.transform.kerb=NONE
The last segment of each property is an identifier used to associate the pattern with the replacement value. When a user makes a request to NiFi Registry, their identity is checked to see if it matches each of those patterns in lexicographical order. For the first one that matches, the replacement specified in the nifi.registry.security.identity.mapping.value.xxxx property is used. So a login with CN=localhost, OU=Apache NiFi, O=Apache, L=Santa Monica, ST=CA, C=US matches the DN mapping pattern above and the DN mapping value $1@$2 is applied. The user is normalized to localhost@Apache NiFi.
In addition to mapping, a transform may be applied. The supported versions are NONE (no transform applied), LOWER (identity lowercased), and UPPER (identity uppercased). If not specified, the default value is NONE.
| These mappings are also applied to the "Initial Admin Identity" in the authorizers.xml file, as well as users imported from LDAP (See Authorizers.xml Setup). |
Group names can also be mapped. The following example will accept the existing group name but will lowercase it. This may be helpful when used in conjunction with an external authorizer.
nifi.registry.security.group.mapping.pattern.anygroup=^(.*)$ nifi.registry.security.group.mapping.value.anygroup=$1 nifi.registry.security.group.mapping.transform.anygroup=LOWER
| These mappings are applied to groups imported from LDAP. |
Providers Properties
These properties pertain to flow persistence providers. NiFi Registry uses a pluggable flow persistence provider to store the content of the flows saved to the registry. For further details on persistence providers, refer Persistence Providers.
Property |
Description |
|
This is the location of the file where flow persistence providers are configured. The default value is |
Alias Properties
These properties pertain to the support for URL aliasing. For further details, refer to URL Aliasing.
Property |
Description |
|
This is the location of the file where URL aliases are configured. The default value is |
Database Properties
These properties define the settings for the Registry database, which keeps track of metadata about buckets and all items stored in buckets.
The 0.1.0 release leveraged an embedded H2 database that was configured via the following properties:
Property |
Description |
|
The location of the Registry database directory. The default value is |
|
This property specifies additional arguments to add to the connection string for the Registry database. The default value should be used and should not be changed. It is: |
The 0.2.0 release introduced a more flexible approach which allows leveraging an external database. This new approach is configured via the following properties:
Property |
Description |
|
The full JDBC connection string. The default value will specify a new H2 database in the same location as the previous one. For example, |
|
The class name of the JDBC driver. The default value is |
|
An optional directory containing one or more JARs to add to the classpath. If not specified, it is assumed that the driver JAR is already on the classpath by copying it to the |
|
The username for the database. The default value is |
|
The password for the database. The default value is |
|
The max number of connections for the connection pool. The default value is |
|
Whether or not enable debug logging for SQL statements. The default value is |
When upgrading from 0.1.0 to a future version, if nifi.registry.db.directory remains populated, the application will
attempt to migrate the data from the original database to the new database specified with the new properties. This will only
happen the first time the application starts with the new database properties.
|
Extension Directories
Each property beginning with nifi.registry.extension.dir. will be treated as location for an extension, and a class loader will be created for each location, with the system class loader as the parent.
Property |
Description |
|
The full path on the filesystem to the location of the JARs for the given extension |
Multiple extension directories can be specified by using the nifi.registry.extension.dir. prefix with unique suffixes and separate paths as values.
For example, to provide an additional extension directory, a user could also specify additional properties with keys of: nifi.registry.extension.dir.2=/path/to/extension2,
providing 2 total locations, including nifi.registry.extension.dir.1.
|
Kerberos Properties
Property |
Description |
|
The location of the krb5 file, if used. It is blank by default. At this time, only a single krb5 file is allowed to
be specified per NiFi instance, so this property is configured here to support SPNEGO and service principals rather than in individual Processors.
If necessary the krb5 file can support multiple realms.
Example: |
|
The name of the NiFi Registry Kerberos SPNEGO principal, if used. It is blank by default. Note that this property is used to authenticate NiFi Registry users.
Example: |
|
The file path of the NiFi Registry Kerberos SPNEGO keytab, if used. It is blank by default. Note that this property is used to authenticate NiFi Registry users.
Example: |
|
The expiration duration of a successful Kerberos user authentication, if used. The default value is |
Metadata Database
The metadata database maintains the knowledge of which buckets exist, which versioned items belong to which buckets, as well as the version history for each item.
Currently, NiFi Registry supports using H2, Postgres (10.x - 13.x), and MySQL (8.0) for the relational database engine.
| NiFi Registry 0.1.0 only supports H2. |
H2
H2 is an embedded database that is pre-configured in the default nifi-registry.properties file. The contents of the H2 database are stored in a file on the local filesystem.
For NiFi Registry 0.1.0, the location of the H2 database is specified by the property:
nifi.registry.db.directory=./database
For NiFi Registry 0.2.0 and forward, the location of the H2 database is specified as part of the JDBC URL property:
nifi.registry.db.url=jdbc:h2:./database/nifi-registry-primary;
Changing password in existing H2 database
-
Download H2 driver from official repository https://www.h2database.com/html/download.html and place it somewhere accessible to NiFi Registry user
-
Run H2 database shell
java -cp h2*.jar org.h2.tools.Shell
-
Connect to database
Welcome to H2 Shell 1.4.200 (2019-10-14) Exit with Ctrl+C URL jdbc:h2:./database/nifi-registry-primary Driver org.h2.Driver User nifireg Password Connected
-
Change password
ALTER USER nifireg SET PASSWORD 'NEW_PASSWORD';
Postgres
Postgres provides the option to use an externally located database that also supports high availability.
The following steps are required to use Postgres:
-
Download the Postgres JDBC driver and place it somewhere accessible to NiFi Registry
/path/to/drivers/postgresql-42.2.2.jar
-
Create a database inside Postgres
createdb nifireg
-
Create a database user and grant privileges
psql nifireg CREATE USER nifireg WITH PASSWORD 'changeme'; GRANT ALL PRIVILEGES ON DATABASE nifireg to nifireg; \q
-
Configure the database properties in nifi-registry.properties
nifi.registry.db.url=jdbc:postgresql://<POSTGRES-HOSTNAME>/nifireg nifi.registry.db.driver.class=org.postgresql.Driver nifi.registry.db.driver.directory=/path/to/drivers nifi.registry.db.username=nifireg nifi.registry.db.password=changeme
MySQL
MySQL also provides the option to use an externally located database that also supports high availability.
The following steps are required to use MySQL:
-
Download the MySQL JDBC driver and place it somewhere accessible to NiFi Registry
/path/to/drivers/mysql-connector-java-8.0.16.jar
-
Create a database inside MySQL (enter mysql shell using
mysql -u root -pCREATE DATABASE nifi_registry;
-
Create a database user and grant privileges (for remote users, use
nifireg'@'<IP-ADDRESS>, ornifireg'@'%for any remote host)GRANT ALL PRIVILEGES ON nifi_registry.* TO 'nifireg'@'localhost' IDENTIFIED BY 'changeme';
-
Configure the database properties in nifi-registry.properties
nifi.registry.db.url=jdbc:mysql://<MYSQL-HOSTNAME>/nifi_registry nifi.registry.db.driver.class=com.mysql.cj.jdbc.Driver nifi.registry.db.driver.directory=/path/to/drivers nifi.registry.db.username=nifireg nifi.registry.db.password=changeme
Schema Differences & Limitations
Due to differences across database implementations, there are two versions of the schema for NiFi Registry’s metadata database. The original version supports H2 and Postgres, and a second versions supports MySQL.
MySQL has limitations on the maximum size of text columns that are part of an index, or unique key. This means the maximum length of some columns is significantly less when using MySQL vs. H2/Postgres.
| If choosing to use MySQL it is important to understand these limitations and accept them. |
The following tables summarizes the schema differences in column lengths:
Table.Column |
H2/Postgres |
MySQL |
BUCKET.NAME |
1000 |
767 |
FLOW_SNAPSHOT.CREATED_BY |
4096 |
767 |
SIGNING_KEY.TENANT_IDENTITY |
4096 |
767 |
BUNDLE.GROUP_ID |
500 |
200 |
BUNDLE.ARTIFACT_ID |
500 |
200 |
BUNDLE_VERSION.CREATED_BY |
4096 |
767 |
BUNDLE_VERSION.BUILT_BY |
4096 |
767 |
BUNDLE_VERSION_DEPENDENCY.GROUP_ID |
500 |
200 |
BUNDLE_VERSION_DEPENDENCY.ARTIFACT_ID |
500 |
200 |
EXTENSION_PROVIDED_SERVICE_API.CLASS_NAME |
500 |
200 |
EXTENSION_PROVIDED_SERVICE_API.GROUP_ID |
500 |
200 |
EXTENSION_PROVIDED_SERVICE_API.ARTIFACT_ID |
500 |
200 |
Persistence Providers
NiFi Registry uses a pluggable persistence provider to store the content of each versioned item. Each type of versioned item, such as a versioned flow or extension bundle, has its own persistence provider.
Each persistence provider has its own configuration parameters, which can be configured in an XML file specified in nifi-registry.properties.
Flow Persistence Providers
The flow persistence provider stores the content of the flows saved to the registry. NiFi Registry provides FileSystemFlowPersistenceProvider and GitFlowPersistenceProvider.
The XML configuration file looks like below. It has a flowPersistenceProvider element in which qualified class name of a persistence provider implementation and its configuration properties are defined. See following sections for available configurations for each provider.
<flowPersistenceProvider>
<class>persistence-provider-qualified-class-name</class>
<property name="property-1">property-value-1</property>
<property name="property-2">property-value-2</property>
<property name="property-n">property-value-n</property>
</flowPersistenceProvider>FileSystemFlowPersistenceProvider
FileSystemFlowPersistenceProvider simply stores serialized Flow contents into {bucket-id}/{flow-id}/{version} directories.
Example of persisted files:
Flow Storage Directory/
├── {bucket-id}/
│ └── {flow-id}/
│ ├── {version}/{version}.snapshot
└── d1beba88-32e9-45d1-bfe9-057cc41f7ce8/
└── 219cf539-427f-43be-9294-0644fb07ca63/
├── 1/1.snapshot
└── 2/2.snapshot
Qualified class name: org.apache.nifi.registry.provider.flow.FileSystemFlowPersistenceProvider
Property |
Description |
|
REQUIRED: File system path for a directory where flow contents files are persisted to. If the directory does not exist when NiFi Registry starts, it will be created. If the directory exists, it must be readable and writable from NiFi Registry. |
GitFlowPersistenceProvider
GitFlowPersistenceProvider stores flow contents under a Git directory.
In contrast to FileSystemFlowPersistenceProvider, this provider uses human friendly Bucket and Flow names so that those files can be accessed by external tools. However, it is NOT supported to modify stored files outside of NiFi Registry. Persisted files are only read when NiFi Registry starts up.
Buckets are represented as directories and Flow contents are stored as files in a Bucket directory they belong to. Flow snapshot histories are managed as Git commits, meaning only the latest version of Buckets and Flows exist in the Git directory. Old versions are retrieved from Git commit histories.
Flow Storage Directory/
├── .git/
├── Bucket_A/
│ ├── bucket.yml
│ ├── Flow_1.snapshot
│ └── Flow_2.snapshot
└── Bucket_B/
├── bucket.yml
└── Flow_4.snapshot
Each Bucket directory contains a YAML file named bucket.yml. The file manages links from NiFi Registry Bucket and Flow IDs to actual directory and file names. When NiFi Registry starts, this provider reads through Git commit histories and lookup these bucket.yml files to restore Buckets and Flows for each snapshot version.
layoutVer: 1
bucketId: d1beba88-32e9-45d1-bfe9-057cc41f7ce8
flows:
219cf539-427f-43be-9294-0644fb07ca63: {ver: 7, file: Flow_1.snapshot}
22cccb6c-3011-4493-a996-611f8f112969: {ver: 3, file: Flow_2.snapshot}Qualified class name: org.apache.nifi.registry.provider.flow.git.GitFlowPersistenceProvider
Property |
Description |
|
REQUIRED: File system path for a directory where flow contents files are persisted to. The directory must exist when NiFi registry starts. Also must be initialized as a Git directory. See Initialize Git directory for detail. |
|
When a new flow snapshot is created, this persistence provider updates files in the specified Git directory, then creates a commit to the local repository. If |
|
This username is used to make push requests to the remote repository when |
|
The password for the |
|
Remote repository URI to use to clone into |
Initialize Git directory
In order to use GitFlowPersistenceRepository, you need to prepare a Git directory on the local file system. You can do so by initializing a directory with git init command, or clone an existing Git project from a remote Git repository by git clone command. If you want to clone the default branch of remote repository automatically, set the Remote Clone Repository as described above.
-
git initcommand https://git-scm.com/docs/git-init -
git clonecommand https://git-scm.com/docs/git-clone
Git user configuration
This persistence provider uses preconfigured Git user name and user email address when it creates Git commits. NiFi Registry user name is added to commit messages.
commit 774d4bd125f2b1200f0a5ee1f1e9fedc6a415e83
Author: git-user <git-user@example.com>
Date: Tue May 8 14:30:31 2018 +0900
Commit message.
By NiFi Registry user: nifi-registry-user-1
You can configure Git user name and email address by git config command.
-
git configcommand https://git-scm.com/docs/git-config
Git user authentication
By default, this persistence repository only create commits to local repository. No user authentication is needed to do so. However, if 'Commit To Push' is enabled, user authentication to the remote Git repository is required.
If the remote repository is accessed by HTTP, then username and password for authentication can be configured in the providers XML configuration file.
When SSH is used, SSH keys are used to identify a Git user. In order to pick the right key to a remote server, the SSH configuration file ${USER_HOME}/.ssh/config is used. The SSH configuration file can contain multiple Host entries to specify a key file to login to a remote Git server. The Host must match with the target remote Git server hostname.
Host git.example.com HostName git.example.com IdentityFile ~/.ssh/id_rsa Host github.com HostName github.com IdentityFile ~/.ssh/key-for-github Host bitbucket.org HostName bitbucket.org IdentityFile ~/.ssh/key-for-bitbucket
DatabaseFlowPersistenceProvider
DatabaseFlowPersistenceProvider stores flow contents in a database table.
This provider leverages the same database used for the metadata database, so there is no configuration to provide since the
connection details will come from the database properties in nifi-registry.properties.
The database table is named FLOW_PERSISTENCE_PROVIDER and has the following schema:
Column |
Description |
BUCKET_ID |
The identifier of the bucket where the flow is located. |
FLOW_ID |
The identifier of the flow. |
VERSION |
The version of the flow. |
FLOW_CONTENT |
The serialized bytes of the flow content stored as a BLOB. |
Switching from other Flow Persistence Provider
In order to switch the Flow Persistence Provider, it is necessary to reset NiFi Registry.
For example, to switch from FileSystemFlowPersistenceProvider to GitFlowPersistenceProvider, follow these steps:
-
Stop version control on all ProcessGroups in NiFi
-
Stop NiFi Registry
-
Move the H2 DB (specified as
nifi.registry.db.directoryin nifi-registry.properties) andFlow Storage DirectoryforFileSystemFlowPersistenceProviderdirectories somewhere for back up -
Configure
GitFlowPersistenceProviderprovider in providers.xml -
Start NiFi Registry
-
Recreate any buckets
-
Start version control on all ProcessGroups again
Data model version of serialized Flow snapshots
Serialized Flow snapshots saved by these persistence providers have versions, so that the data format and schema can evolve over time. Data model version update is done automatically by NiFi Registry when it reads and stores each Flow content.
Here is the data model version histories:
Data model version |
Since NiFi Registry |
Description |
2 |
0.2 |
JSON formatted text file. The root object contains header and Flow content object. |
1 |
0.1 |
Binary format having header bytes at the beginning followed by Flow content represented as XML. |
Bundle Persistence Providers
The bundle persistence provider stores the content of extension bundles saved to the registry. NiFi Registry provides FileSystemBundlePersistenceProvider and S3BundlePersistenceProvider.
The XML configuration file looks like below. It has a extensionBundlePersistenceProvider element in which the qualified class name of a persistence provider implementation and its configuration properties are defined. See following sections for available configurations for each provider.
<extensionBundlePersistenceProvider>
<class>persistence-provider-qualified-class-name</class>
<property name="property-1">property-value-1</property>
<property name="property-2">property-value-2</property>
<property name="property-n">property-value-n</property>
</extensionBundlePersistenceProvider>FileSystemBundlePersistenceProvider
The FileSystemBundlePersistenceProvider stores the content of extension bundles on the local file system. The bundles are organized in directories according to bucket id, group, artifact, and version.
Example of persisted extension bundles:
Extension Bundle Storage Directory/
├── {bucket-id}/
└── {group-id}/
└── {artifact-id}
└── {version}/{artifact-id}-{version}.{extension}
├── d1beba88-32e9-45d1-bfe9-057cc41f7ce8/
└── org.apache.nifi
└── nifi-example-nar
└── 1.0.0/nifi-example-nar-1.0.0.nar
└── 2.0.0/nifi-example-nar-2.0.0.nar
Configuration
Qualified class name: org.apache.nifi.registry.provider.extension.FileSystemBundlePersistenceProvider
Property |
Description |
|
REQUIRED: File system path for a directory where extension bundle contents files are persisted to. If the directory does not exist when NiFi Registry starts, it will be created. If the directory exists, it must be readable and writable from NiFi Registry. |
S3BundlePersistenceProvider
The S3BundlePersistenceProvider stores the content of extension bundles in a AWS S3 bucket. The bucket is expected to already exist and be accessible to the credentials provided to the persistence providcer.
This provider must be added to the classpath by specifying a custom extension directory in nifi-registry.properties, such as nifi.registry.extension.dir.aws=./ext/aws/lib, where ./ext/aws/ contains the contents of the extracted nifi-registry-aws-assembly-<version>-bin.zip.
|
The key of an extension bundle in the S3 bucket will be the following:
/{registry-bucket-id}/{group-id}/{artifact-id}/{version}/{artifact-id}-{version}.{extension}
If an optional Key Prefix is specified, then that prefix will be applied to the beginning of the above key.
Configuration
Qualified class name: org.apache.nifi.registry.aws.S3BundlePersistenceProvider
Property |
Description |
|
REQUIRED: The name of the S3 region where the bucket exists. |
|
REQUIRED: The name of an existing bucket to store extension bundles. |
|
An optional prefix that if specified will be added to the beginning of all S3 keys. |
|
REQUIRED: Indicates how credentials will be provided, must be a value of |
|
The access key to use when using |
|
The secret access key to use when using |
|
An optional URL that overrides the default AWS S3 endpoint URL. Set this when using an AWS S3 API compatible service hosted at a different URL. |
Event Hooks
Event hooks are an integration point that allows for custom code to to be triggered when NiFi Registry application events occur.
| Event Name | Description |
|---|---|
|
A new registry bucket is created. |
|
A new flow is created in a specified bucket. Only triggered on first time creation of a flow with a given name. |
|
A new version for a flow has been saved in the registry. |
|
A bucket has been updated. |
|
A flow that exist in a bucket has been updated. |
|
An existing bucket in the registry is deleted. |
|
An existing flow in the registry is deleted. |
|
Invoked once the NiFi Registry application has been successfully started. This is only invoked after a complete and successful start. |
Shared Event Hook Properties
There are certain properties that are shared amongst all of the NiFi Registry provided Event Hook implementations. Those properties and their purpose are listed below.
| Property Name | Description |
|---|---|
|
Event types the hook provider configured with this property should respond to. If this property is left blank or not provided, all events will fire for the configured hook provider. Multiple |
ScriptEventHookProvider
The ScriptEventHookProvider invokes a shell script that has been written by a user and placed on a file system that is accessible
by the NiFi Registry instance that the provider is configured for.
<eventHookProvider>
<class>org.apache.nifi.registry.provider.hook.ScriptEventHookProvider</class>
<property name="Script Path"></property>
<property name="Working Directory"></property>
<!-- optional -->
<property name="Whitelisted Event Type 1">CREATE_FLOW</property>
<property name="Whitelisted Event Type 2">UPDATE_FLOW</property>
</eventHookProvider>
| Property Name | Description |
|---|---|
|
Full path to a script that will executed for each event. The arguments to the script will be the event fields in the order they are specified for the given event type. |
|
Working directory from where the commands will be executed. |
LoggingEventHookProvider
The LoggingEventHookProvider logs a string representation of each event using an SLF4J logger. The logger can be configured
via NiFi Registry’s logback.xml, which by default contains an appender that writes to a log file named nifi-registry-event.log in the logs directory.
<eventHookProvider>
<class>org.apache.nifi.registry.provider.hook.LoggingEventHookProvider</class>
</eventHookProvider>
URL Aliasing
A versioned item may contain the URL of a registry instance embedded in the content of the item. For example, flows with nested versioning contain the URL of the registry where the nested versioned flow is located. If the location of the registry instances changes, then the content is no longer accurate.
URL aliasing can be used to dynamically handle this situation so that URLs are never written to the stored content, and can be re-written with the correct value when being retrieved by a client.
The aliases are configured in an XML file which can be specified in nifi-registry.properties.
<aliases>
<alias>
<internal>NIFI_REGISTRY_1</internal>
<external>http://registry1.nifi.apache.org:18080</external>
</alias>
<alias>
<internal>NIFI_REGISTRY_2</internal>
<external>http://registry2.nifi.apache.org:18080</external>
</alias>
</aliases>If a flow is saved to registry with two child process groups, each under version control, the incoming flow would contain something like the following:
"processGroups" : [ {
...
"versionedFlowCoordinates" : {
"bucketId" : "ca20e058-f6e7-404c-aee0-e30833e792c7",
"flowId" : "178a6657-e1a7-4cce-8f83-4e615e38f57a",
"registryUrl" : "http://registry1.nifi.apache.org:18080",
"version" : 1
},
{
...
"versionedFlowCoordinates" : {
"bucketId" : "ca20e058-f6e7-404c-aee0-e30833e792c7",
"flowId" : "985cb44b-3aec-32be-860f-d2a0f2c72aac",
"registryUrl" : "http://registry2.nifi.apache.org:18080",
"version" : 1
}
]
With the example aliases configuration above, the URLs would be written to the flow persistence provider as the following:
"processGroups" : [ {
...
"versionedFlowCoordinates" : {
"bucketId" : "ca20e058-f6e7-404c-aee0-e30833e792c7",
"flowId" : "178a6657-e1a7-4cce-8f83-4e615e38f57a",
"registryUrl" : "NIFI_REGISTRY_1",
"version" : 1
},
{
...
"versionedFlowCoordinates" : {
"bucketId" : "ca20e058-f6e7-404c-aee0-e30833e792c7",
"flowId" : "985cb44b-3aec-32be-860f-d2a0f2c72aac",
"registryUrl" : "NIFI_REGISTRY_2",
"version" : 1
}
]
When this flow is retrieved from any API call, the internal values would be rewritten to the external values.
Backup & Recovery
In order to prevent data loss it is important to consider backup and recovery options. The data that needs to be considered is the following:
-
Metadata Database
-
Persistence providers
-
Configuration files
Metadata Database
If using H2, the database file should be backed up periodically to an external location. In order to ensure a proper backup, NiFi Registry should be stopped to ensure no write operations are occurring while copying the file.
If using Postgres, backups may be taken on the Postgres database, or Postgres may be configured for high availability such that there is a failover or backup instance.
If starting a brand new NiFi Registry instance, the metadata database can be automatically rebuilt from the information in the GitFlowPersistenceProvider. This is a one-time operation during the first start of the application, and is not meant to keep the DB in sync with external changes made in Git. This feature only applies to flows and would not be able to restore information about extension bundles.
Persistence Providers
Each persistence provider may have its own option for backup & recovery.
Flow Persistence
If using the FileSystemFlowPersistenceProvider, the directory where flows are stored should be backed up periodically to an external location. In order to ensure a proper backup, NiFi Registry should be stopped to ensure no flows are being written to disk. If using H2 for metadata, H2 should be backed up at the same time to ensure consistency between the flows on disk and the contents in H2.
If using the GitFlowPersistenceProvider, the ability to automatically push to a remote may be configured. This provides an automatic backup of the data in the remote repo.
Bundle Persistence
If using the FileSystemBundlePersistenceProvider, the directory where bundles are stored should be backed up periodically to an external location. In order to ensure a proper backup, NiFi Registry should be stopped to ensure no bundles are being written to disk. If using H2 for metadata, H2 should be backed up at the same time to ensure consistency between the bundles on disk and the contents in H2.
If using the S3BundlePersistenceProvider, data will be stored remotely and automatically replicated.
Configuration Files
If using NiFi Registry’s policy based authorization, the users, groups, and policies are stored in files on disk named users.xml and authorizations.xml. These files should be periodically backed up to an external location. In order to ensure a proper backup, NiFi Registry should be stopped to ensure no authorization data is being written to disk.
If using Ranger, then all authorization information is stored externally and there is nothing to back up.