Getting started with Flink native Kubernetes for Amazon EMR on EKS

Before you can run a Flink application with the Flink Native Kubernetes command, complete the steps in Setting up Flink Native Kubernetes for Amazon EMR on EKS.

Download and install Flink.

Set the values for the following environment variables.

#Export the FLINK_HOME environment variable to your local installation of Flink
export FLINK_HOME=/usr/local/bin/flink #Will vary depending on your installation
export NAMESPACE=flink
export CLUSTER_ID=flink-application-cluster
export IMAGE=<123456789012.dkr.ecr.sample-Amazon Web Services Region-.amazonaws.com/flink/emr-6.13.0-flink:latest>
export FLINK_SERVICE_ACCOUNT=emr-containers-sa-flink
export FLINK_CLUSTER_ROLE_BINDING=emr-containers-crb-flink

Create a service account to manage Kubernetes resources.

kubectl create serviceaccount $FLINK_SERVICE_ACCOUNT -n $NAMESPACE
kubectl create clusterrolebinding $FLINK_CLUSTER_ROLE_BINDING --clusterrole=edit --serviceaccount=$NAMESPACE:$FLINK_SERVICE_ACCOUNT

Run the run-application CLI command.

$FLINK_HOME/bin/flink run-application \
    --target kubernetes-application \
    -Dkubernetes.namespace=$NAMESPACE \
    -Dkubernetes.cluster-id=$CLUSTER_ID \
    -Dkubernetes.container.image.ref=$IMAGE \
    -Dkubernetes.service-account=$FLINK_SERVICE_ACCOUNT \
    local:///opt/flink/examples/streaming/Iteration.jar
2022-12-29 21:13:06,947 INFO  org.apache.flink.kubernetes.utils.KubernetesUtils            [] - Kubernetes deployment requires a fixed port. Configuration blob.server.port will be set to 6124
2022-12-29 21:13:06,948 INFO  org.apache.flink.kubernetes.utils.KubernetesUtils            [] - Kubernetes deployment requires a fixed port. Configuration taskmanager.rpc.port will be set to 6122
2022-12-29 21:13:07,861 WARN  org.apache.flink.kubernetes.KubernetesClusterDescriptor      [] - Please note that Flink client operations(e.g. cancel, list, stop, savepoint, etc.) won't work from outside the Kubernetes cluster since 'kubernetes.rest-service.exposed.type' has been set to ClusterIP.
2022-12-29 21:13:07,868 INFO  org.apache.flink.kubernetes.KubernetesClusterDescriptor      [] - Create flink application cluster flink-application-cluster successfully, JobManager Web Interface: http://flink-application-cluster-rest.flink:8081
                 

Examine the created Kubernetes resources.

kubectl get all -n <namespace>
NAME READY STATUS RESTARTS AGE
pod/flink-application-cluster-546687cb47-w2p2z 1/1 Running 0 3m37s
pod/flink-application-cluster-taskmanager-1-1 1/1 Running 0 3m24s

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/flink-application-cluster ClusterIP None <none> 6123/TCP,6124/TCP 3m38s
service/flink-application-cluster-rest ClusterIP 10.100.132.158 <none> 8081/TCP 3m38s

NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/flink-application-cluster 1/1 1 1 3m38s

NAME DESIRED CURRENT READY AGE
replicaset.apps/flink-application-cluster-546687cb47 1 1 1 3m38s
                     

Port forward to 8081.

kubectl port-forward service/flink-application-cluster-rest 8081 -n <namespace>
Forwarding from 127.0.0.1:8081 -> 8081

Locally access the Flink UI.

Delete the Flink application.

kubectl delete deployment.apps/flink-application-cluster -n <namespace>
deployment.apps "flink-application-cluster" deleted