Package org.apache.nifi.registry.flow

Interface FlowRegistryClient

All Superinterfaces:

ConfigurableComponent

All Known Implementing Classes:

AbstractFlowRegistryClient

public interface FlowRegistryClient
extends ConfigurableComponent

Represents and external source, where flows might be stored and retrieved from. The interface provides the possibility to have multiple different types of registries backing NiFi.

FlowRegistryClients are discovered using Java's ServiceLoader mechanism. As a result, all implementations must follow these rules:

• The implementation must implement this interface.
• The implementation must have a file named org.apache.nifi.registry.flow.FlowRegistryClient located within the jar's META-INF/services directory. This file contains a list of fully-qualified class names of all FlowRegistryClients in the jar, one-per-line.
• The implementation must support a default constructor.

FlowRegistryClient instances are always considered "active" and approachable when the validation status is considered as valid. Therefore after initialize, implementations must expect incoming requests any time.

The argument list of the request methods contain instances FlowRegistryClientConfigurationContext, which always contains the current state of the properties. Caching properties between method calls is not recommended.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_BRANCH_NAME

Method Summary

Modifier and Type	Method	Description
RegisteredFlow	deregisterFlow(FlowRegistryClientConfigurationContext context, FlowLocation flowLocation)	Deletes the specified flow from the Flow Registry.
default String	generateFlowId(String flowName)	Generates the id for registering a flow.
default Set<FlowRegistryBranch>	getBranches(FlowRegistryClientConfigurationContext context)	Get the available branches.
FlowRegistryBucket	getBucket(FlowRegistryClientConfigurationContext context, BucketLocation bucketLocation)	Gets the bucket with the given id.
Set<FlowRegistryBucket>	getBuckets(FlowRegistryClientConfigurationContext context, String branch)	Gets the buckets for the specified user.
default FlowRegistryBranch	getDefaultBranch(FlowRegistryClientConfigurationContext context)	Gets the default branch.
RegisteredFlow	getFlow(FlowRegistryClientConfigurationContext context, FlowLocation flowLocation)	Retrieves a flow by bucket id and Flow id.
RegisteredFlowSnapshot	getFlowContents(FlowRegistryClientConfigurationContext context, FlowVersionLocation flowVersionLocation)	Retrieves the contents of the flow snapshot with the given Bucket id, Flow id, and version, from the Registry.
Set<RegisteredFlow>	getFlows(FlowRegistryClientConfigurationContext context, BucketLocation bucketLocation)	Retrieves the set of all Flows for the specified bucket.
Set<RegisteredFlowSnapshotMetadata>	getFlowVersions(FlowRegistryClientConfigurationContext context, FlowLocation flowLocation)	Retrieves the set of all versions of the specified flow.
Optional<String>	getLatestVersion(FlowRegistryClientConfigurationContext context, FlowLocation flowLocation)	Returns the latest (most recent) version of the Flow in the Flow Registry for the given bucket and Flow.
void	initialize(FlowRegistryClientInitializationContext context)
default boolean	isBranchingSupported(FlowRegistryClientConfigurationContext context)	Indicates if the registry supports branching.
boolean	isStorageLocationApplicable(FlowRegistryClientConfigurationContext context, String location)	Decides if the given location is applicable by the repository instance.
RegisteredFlow	registerFlow(FlowRegistryClientConfigurationContext context, RegisteredFlow flow)	Registers the given RegisteredFlow into the Flow Registry.
RegisteredFlowSnapshot	registerFlowSnapshot(FlowRegistryClientConfigurationContext context, RegisteredFlowSnapshot flowSnapshot, RegisterAction action)	Adds the given snapshot to the Flow Registry for the given Flow.

Methods inherited from interface org.apache.nifi.components.ConfigurableComponent

getIdentifier, getPropertyDescriptor, getPropertyDescriptors, onPropertyModified, validate

Field Details

DEFAULT_BRANCH_NAME

static final String DEFAULT_BRANCH_NAME

See Also:

• Constant Field Values

Method Details

initialize

void initialize(FlowRegistryClientInitializationContext context)

isStorageLocationApplicable

boolean isStorageLocationApplicable(FlowRegistryClientConfigurationContext context,
 String location)

Decides if the given location is applicable by the repository instance. The format depends on the implementation.

Parameters:

context - Configuration context.

location - The location of versioned flow to check.

Returns:

True in case of the given storage location is applicable, false otherwise. An applicable location does not mean that the flow specified by the location is stored in the registry. Depending on the implementation it might be merely a static check on the format of the location string. In case of uncertainty, NiFi tries to load the versioned flow from registries with true return value first.

isBranchingSupported

default boolean isBranchingSupported(FlowRegistryClientConfigurationContext context)

Indicates if the registry supports branching. If the registry does not supporting branching, then this method should return false and the registry client should use the default implementations of getBranches and getDefaultBranch. If the registry does support branching, then this method should return true and the registry client should use override getBranches and getDefaultBranch to provide appropriate implementations.

Parameters:

context - Configuration context

Returns:

true if the registry supports branching, false otherwise

getBranches

default Set<FlowRegistryBranch> getBranches(FlowRegistryClientConfigurationContext context)
                                     throws FlowRegistryException,
IOException

Get the available branches. Should return at least one branch that matches the response of getDefaultBranch.

Parameters:

context - Configuration context

Returns:

the set of available branches

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getDefaultBranch

default FlowRegistryBranch getDefaultBranch(FlowRegistryClientConfigurationContext context)
                                     throws FlowRegistryException,
IOException

Gets the default branch. Must return a non-null FlowRegistryBranch instance with a non-null name. The interface provides a default implementation which will return a branch named 'main'.

Parameters:

context - Configuration context

Returns:

the default branch

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getBuckets

Set<FlowRegistryBucket> getBuckets(FlowRegistryClientConfigurationContext context,
 String branch)
                            throws FlowRegistryException,
IOException

Gets the buckets for the specified user.

Parameters:

context - Configuration context.

branch - the branch

Returns:

Buckets for this user. In case there are no available buckets for the user the result will be an empty set.

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getBucket

FlowRegistryBucket getBucket(FlowRegistryClientConfigurationContext context,
 BucketLocation bucketLocation)
                      throws FlowRegistryException,
IOException

Gets the bucket with the given id.

Parameters:

context - Configuration context.

bucketLocation - The location of the bucket.

Returns:

The bucket with the given id.

Throws:

NoSuchBucketException - If there is no bucket in the Registry with the given id.

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

registerFlow

RegisteredFlow registerFlow(FlowRegistryClientConfigurationContext context,
 RegisteredFlow flow)
                     throws FlowRegistryException,
IOException

Registers the given RegisteredFlow into the Flow Registry.

Parameters:

context - Configuration context.

flow - The RegisteredFlow to add to the Registry.

Returns:

The fully populated RegisteredFlow

Throws:

FlowAlreadyExistsException - If a Flow with the given identifier already exists in the registry.

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

deregisterFlow

RegisteredFlow deregisterFlow(FlowRegistryClientConfigurationContext context,
 FlowLocation flowLocation)
                       throws FlowRegistryException,
IOException

Deletes the specified flow from the Flow Registry.

Parameters:

context - Configuration context.

flowLocation - the location of the flow

Returns:

The deleted Flow.

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getFlow

RegisteredFlow getFlow(FlowRegistryClientConfigurationContext context,
 FlowLocation flowLocation)
                throws FlowRegistryException,
IOException

Retrieves a flow by bucket id and Flow id.

Parameters:

context - Configuration context.

flowLocation - the location of the flow

Returns:

The Flow for the given bucket and Flow id's.

Throws:

NoSuchFlowException - If there is no Flow in the bucket with the given id.

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getFlows

Set<RegisteredFlow> getFlows(FlowRegistryClientConfigurationContext context,
 BucketLocation bucketLocation)
                      throws FlowRegistryException,
IOException

Retrieves the set of all Flows for the specified bucket.

Parameters:

context - Configuration context.

bucketLocation - the location of the bucket

Returns:

The set of all Flows from the specified bucket. In case there are no available flows in the bucket the result will be an empty set.

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getFlowContents

RegisteredFlowSnapshot getFlowContents(FlowRegistryClientConfigurationContext context,
 FlowVersionLocation flowVersionLocation)
                                throws FlowRegistryException,
IOException

Retrieves the contents of the flow snapshot with the given Bucket id, Flow id, and version, from the Registry.

Parameters:

context - Configuration context.

flowVersionLocation - the location of the flow version

Returns:

The contents of the Flow from the Flow Registry.

Throws:

NoSuchFlowVersionException - If there is no version of the Flow with the given version number.

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

registerFlowSnapshot

RegisteredFlowSnapshot registerFlowSnapshot(FlowRegistryClientConfigurationContext context,
 RegisteredFlowSnapshot flowSnapshot,
 RegisterAction action)
                                     throws FlowRegistryException,
IOException

Adds the given snapshot to the Flow Registry for the given Flow.

Parameters:

context - Configuration context.

flowSnapshot - The flow snapshot to register.

action - The register action

Returns:

The flow snapshot.

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getFlowVersions

Set<RegisteredFlowSnapshotMetadata> getFlowVersions(FlowRegistryClientConfigurationContext context,
 FlowLocation flowLocation)
                                             throws FlowRegistryException,
IOException

Retrieves the set of all versions of the specified flow.

Parameters:

context - Configuration context.

flowLocation - the location of the flow

Returns:

The set of all versions of the specified flow. In case there are no available versions for the specified flow the result will be an empty set.

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

getLatestVersion

Optional<String> getLatestVersion(FlowRegistryClientConfigurationContext context,
 FlowLocation flowLocation)
                           throws FlowRegistryException,
IOException

Returns the latest (most recent) version of the Flow in the Flow Registry for the given bucket and Flow.

Parameters:

context - Configuration context.

flowLocation - the location of the flow

Returns:

an Optional containing the latest version of the flow, or empty if no versions exist for the flow

Throws:

FlowRegistryException - If an issue happens during processing the request.

IOException - If there is issue with the communication between NiFi and the Flow Registry.

generateFlowId

default String generateFlowId(String flowName)

Generates the id for registering a flow.

Parameters:

flowName - the name of the flow

Returns:

the generated id