org.apache.flink.kubernetes.kubeclient

Interface FlinkKubeClient

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

Fabric8FlinkKubeClient

public interface FlinkKubeClient
extends AutoCloseable

The client to talk with kubernetes. The interfaces will be called both in Client and ResourceManager. To avoid potentially blocking the execution of RpcEndpoint's main thread, these interfaces createTaskManagerPod(KubernetesPod), stopPod(String) should be implemented asynchronously.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	FlinkKubeClient.WatchCallbackHandler<T> Callback handler for kubernetes resources.

Method Summary

Modifier and Type	Method and Description
CompletableFuture<Boolean>	checkAndUpdateConfigMap(String configMapName, Function<KubernetesConfigMap,Optional<KubernetesConfigMap>> updateFunction) Update an existing ConfigMap with the data.
void	close() Close the Kubernetes client with no exception.
CompletableFuture<Void>	createConfigMap(KubernetesConfigMap configMap) Create the ConfigMap with specified content.
KubernetesConfigMapSharedWatcher	createConfigMapSharedWatcher(String name) Create a shared watcher for ConfigMaps with specified name.
void	createJobManagerComponent(KubernetesJobManagerSpecification kubernetesJMSpec) Create the Master components, this can include the Deployment, the ConfigMap(s), and the Service(s).
KubernetesLeaderElector	createLeaderElector(KubernetesLeaderElectionConfiguration leaderElectionConfiguration, KubernetesLeaderElector.LeaderCallbackHandler leaderCallbackHandler) Create a leader elector service based on Kubernetes api.
CompletableFuture<Void>	createTaskManagerPod(KubernetesPod kubernetesPod) Create task manager pod.
CompletableFuture<Void>	deleteConfigMap(String configMapName) Delete a Kubernetes ConfigMap by name.
Optional<KubernetesConfigMap>	getConfigMap(String name) Get the ConfigMap with specified name.
List<KubernetesPod>	getPodsWithLabels(Map<String,String> labels) List the pods with specified labels.
Optional<Endpoint>	getRestEndpoint(String clusterId) Get the rest endpoint for access outside cluster.
Optional<KubernetesService>	getService(String serviceName) Get the kubernetes service of the given flink clusterId.
KubernetesPod	loadPodFromTemplateFile(File podTemplateFile) Load pod from template file.
void	stopAndCleanupCluster(String clusterId) Stop cluster and clean up all resources, include services, auxiliary services and all running pods.
CompletableFuture<Void>	stopPod(String podName) Stop a specified pod by name.
CompletableFuture<Void>	updateServiceTargetPort(String serviceName, String portName, int targetPort) Update the target ports of the given Kubernetes service.
CompletableFuture<KubernetesWatch>	watchPodsAndDoCallback(Map<String,String> labels, FlinkKubeClient.WatchCallbackHandler<KubernetesPod> podCallbackHandler) Watch the pods selected by labels and do the FlinkKubeClient.WatchCallbackHandler.

Method Detail

createJobManagerComponent

void createJobManagerComponent(KubernetesJobManagerSpecification kubernetesJMSpec)

Create the Master components, this can include the Deployment, the ConfigMap(s), and the Service(s).

Parameters:

kubernetesJMSpec - jobmanager specification

createTaskManagerPod

CompletableFuture<Void> createTaskManagerPod(KubernetesPod kubernetesPod)

Create task manager pod.

Parameters:

kubernetesPod - taskmanager pod

Returns:

Return the taskmanager pod creation future

stopPod

CompletableFuture<Void> stopPod(String podName)

Stop a specified pod by name.

Parameters:

podName - pod name

Returns:

Return the pod stop future

stopAndCleanupCluster

void stopAndCleanupCluster(String clusterId)

Stop cluster and clean up all resources, include services, auxiliary services and all running pods.

Parameters:

clusterId - cluster id

getService

Optional<KubernetesService> getService(String serviceName)

Get the kubernetes service of the given flink clusterId.

Parameters:

serviceName - the name of the service

Returns:

Return the optional kubernetes service of the specified name.

getRestEndpoint

Optional<Endpoint> getRestEndpoint(String clusterId)

Get the rest endpoint for access outside cluster.

Parameters:

clusterId - cluster id

Returns:

Return empty if the service does not exist or could not extract the Endpoint from the service.

getPodsWithLabels

List<KubernetesPod> getPodsWithLabels(Map<String,String> labels)

List the pods with specified labels.

Parameters:

labels - labels to filter the pods

Returns:

pod list

watchPodsAndDoCallback

CompletableFuture<KubernetesWatch> watchPodsAndDoCallback(Map<String,String> labels,
                                                          FlinkKubeClient.WatchCallbackHandler<KubernetesPod> podCallbackHandler)
                                                   throws Exception

Watch the pods selected by labels and do the FlinkKubeClient.WatchCallbackHandler.

Parameters:

labels - labels to filter the pods to watch

podCallbackHandler - podCallbackHandler which reacts to pod events

Returns:

Return a watch for pods. It needs to be closed after use.

Throws:

Exception

createLeaderElector

KubernetesLeaderElector createLeaderElector(KubernetesLeaderElectionConfiguration leaderElectionConfiguration,
                                            KubernetesLeaderElector.LeaderCallbackHandler leaderCallbackHandler)

Create a leader elector service based on Kubernetes api.

Parameters:

leaderElectionConfiguration - election configuration

leaderCallbackHandler - Callback when the current instance is leader or not.

Returns:

Return the created leader elector. It should be started manually via KubernetesLeaderElector#run.

createConfigMap

CompletableFuture<Void> createConfigMap(KubernetesConfigMap configMap)

Create the ConfigMap with specified content. If the ConfigMap already exists, a KubernetesException will be thrown.

Parameters:

configMap - ConfigMap to be created.

Returns:

Return the ConfigMap create future. The returned future will be completed exceptionally if the ConfigMap already exists.

getConfigMap

Optional<KubernetesConfigMap> getConfigMap(String name)

Get the ConfigMap with specified name.

Parameters:

name - name of the ConfigMap to retrieve.

Returns:

Return the ConfigMap, or empty if the ConfigMap does not exist.

checkAndUpdateConfigMap

CompletableFuture<Boolean> checkAndUpdateConfigMap(String configMapName,
                                                   Function<KubernetesConfigMap,Optional<KubernetesConfigMap>> updateFunction)

Update an existing ConfigMap with the data. Benefit from resource version and combined with getConfigMap(String), we could perform a get-check-and-update transactional operation. Since concurrent modification could happen on a same ConfigMap, the update operation may fail. We need to retry internally in the implementation.

Parameters:

configMapName - configMapName specifies the name of the ConfigMap which shall be updated.

updateFunction - Function to be applied to the obtained ConfigMap and get a new updated one. If the returned optional is empty, we will not do the update.

Returns:

Return the ConfigMap update future. The boolean result indicates whether the ConfigMap is updated. The returned future will be completed exceptionally if the ConfigMap does not exist. A failure during the update operation will result in the future failing with a PossibleInconsistentStateException indicating that no clear decision can be made on whether the update was successful or not. The PossibleInconsistentStateException not being present indicates that the failure happened before writing the updated ConfigMap to Kubernetes. For the latter case, it can be assumed that the ConfigMap was not updated.

deleteConfigMap

CompletableFuture<Void> deleteConfigMap(String configMapName)

Delete a Kubernetes ConfigMap by name.

Parameters:

configMapName - ConfigMap name

Returns:

Return the delete future.

createConfigMapSharedWatcher

KubernetesConfigMapSharedWatcher createConfigMapSharedWatcher(String name)

Create a shared watcher for ConfigMaps with specified name.

Parameters:

name - name of the ConfigMap to watch.

Returns:

Return a shared watcher.

close

void close()

Close the Kubernetes client with no exception.

Specified by:

close in interface AutoCloseable

loadPodFromTemplateFile

KubernetesPod loadPodFromTemplateFile(File podTemplateFile)

Load pod from template file.

Parameters:

podTemplateFile - The pod template file.

Returns:

Return a Kubernetes pod loaded from the template.

updateServiceTargetPort

CompletableFuture<Void> updateServiceTargetPort(String serviceName,
                                                String portName,
                                                int targetPort)

Update the target ports of the given Kubernetes service.

Parameters:

serviceName - The name of the service which needs to be updated

portName - The port name which needs to be updated

targetPort - The updated target port

Returns:

Return the update service target port future