Deploying Custom Classes With the User Code Namespace

Learn how to deploy custom classes with the User Code Namespace

Context

In this tutorial, you’ll do the following:

  • Deploy Hazelcast with userCodeNamespaces enabled.

  • Create a custom EntryListener class and package it into a JAR.

  • Upload the JAR file to cloud storage.

  • Apply a UserCodeNamespace resource, referencing the JAR in storage.

  • Create a Map resource with the EntryListener, setting userCodeNamespaces the same as the UserCodeNamespace object.

Before you Begin

You need the following:

Step 1. Start the Hazelcast Cluster

  1. Create a license secret

    Create a secret with your Hazelcast Enterprise License.

    kubectl create secret generic hazelcast-license-key --from-literal=license-key=<hz-license-key>

  2. Create the Hazelcast Cluster

    Run the following command to create the Hazelcast cluster with Persistence enabled using External type.

    kubectl apply -f - <<EOF
apiVersion: hazelcast.com/v1alpha1
kind: Hazelcast
metadata:
  name: hazelcast
spec:
  clusterSize: 1
  repository: "docker.io/hazelcast/hazelcast-enterprise"
  version: "5.5.4"
  licenseKeySecretName: hazelcast-license-key
  userCodeNamespaces: {}
EOF

  3. Check the Cluster Status

    Run the following commands to see the cluster status

    $ kubectl get hazelcast hazelcast
NAME        STATUS    MEMBERS
hazelcast   Running   1/1

Step 2. Deploy the EntryListener JAR to Cloud Storage

In this step, you’ll build the EntryListener JAR from the tutorial’s GitHub repository, and upload it to your cloud provider.

  1. Clone the sample project.

    • HTTPS

    • SSH

    git clone https://github.com/hazelcast-guides/hazelcast-platform-operator-user-code-namespace.git

cd hazelcast-platform-operator-user-code-namespace
    git clone git@github.com:hazelcast-guides/hazelcast-platform-operator-user-code-namespace.git

cd hazelcast-platform-operator-user-code-namespace

    The sample code for this tutorial is in the simple-entry-listener/src/main/java/com/hazelcast/tutorial/ directory:

  2. Build the SimpleEntryListener JAR.

    mvn package -f ./simple-entry-listener

  3. Upload the SimpleEntryListener JAR to the storage blob/bucket of your cloud provider, replacing the placeholder values.

    • S3

    • GCS

    • ABS

    aws s3 cp simple-entry-listener/target/simple-entry-listener-1.0-SNAPSHOT.jar s3://<BUCKET_NAME>
    gsutil cp simple-entry-listener/target/simple-entry-listener-1.0-SNAPSHOT.jar gs://<BUCKET_NAME>
    az storage blob upload --account-name <ACCOUNT_NAME> --container-name <CONTAINER_NAME> --file simple-entry-listener/target/simple-entry-listener-1.0-SNAPSHOT.jar

  4. Create a secret for your cloud storage by running one of the following commands. Remember to replace the placeholder values.

    • AWS

    • GCP

    • Azure

    kubectl create secret generic <SECRET-NAME> --from-literal=region=<region> \
	--from-literal=access-key-id=<access-key-id> \
	--from-literal=secret-access-key=<secret-access-key>
    kubectl create secret generic <SECRET-NAME> --from-file=google-credentials-path=<service_account_json_file>
    kubectl create secret generic <SECRET-NAME> \
	--from-literal=storage-account=<storage-account> \
	--from-literal=storage-key=<storage-key>

Step 3. Apply the UserCodeNamespace resource

  1. Apply the UserCodeNamespace resource

    Run the following command to create the UserCodeNamespace, referencing to the bucket where the EntryLister JAR is located.

    kubectl apply -f - <<EOF
apiVersion: hazelcast.com/v1alpha1
kind: UserCodeNamespace
metadata:
  name: my-ucn
spec:
  hazelcastResourceName: hazelcast
  bucketConfig:
    secretName: <SECRET_NAME>
    bucketURI: <BUCKET_URI>
EOF

  2. Check the status of the UserCodeNamespace resource

    Run the following command to check the status of the UserCodeNamespace resource

    $ kubectl get ucn my-ucn
NAME     STATUS
my-ucn   Success

    It verifies that:

    • The user code namespaces called my-ucn is created.

    • The jars in the bucket are downloaded into the members’ classpath.

    • The classes in the jars are added to the my-ucn namespace.

Step 4. Create the Map with the EntryListener

  1. Create the Map in a specific namespace

    Run the following command to create the Map with the SimpleEntryListener class in the my-ucn namespace.

    kubectl apply -f - <<EOF
apiVersion: hazelcast.com/v1alpha1
kind: Map
metadata:
  name: my-map
spec:
  hazelcastResourceName: hazelcast
  userCodeNamespace: my-ucn
  entryListeners:
    - className: com.hazelcast.tutorial.SimpleEntryListener
EOF

  2. Check the status of the Map

    Run the following command to check the status of the Map

    $ kubectl get map my-map
NAME     STATUS
my-map   Success

    The status of my-map is Success, indicating that the map was successfully created with the user code namespace my-ucn and includes one EntryListener class, com.hazelcast.tutorial.SimpleEntryListener.

    You can optionally put some entries to the map to observe the EntryListener in action.

    $ kubectl logs hazelcast-0
Entry Added:EntryEvent{entryEventType=ADDED, member=Member [10.80.2.23]:5702 - 237432e4-7a74-49ec-a2e5-d13ac9a8a41c this, name='my-map', key=gSMjgutLELKzZEEn, oldValue=null, value=LXqfGSOlYSIhMbTETLCNXgrYGbmdxCEpwmbPzmRkJjUCWUCu, mergingValue=null}
Entry Added:EntryEvent{entryEventType=ADDED, member=Member [10.80.2.23]:5702 - 237432e4-7a74-49ec-a2e5-d13ac9a8a41c this, name='my-map', key=MehMxfDQQAzSlJHc, oldValue=null, value=GJTqmcmeSGPbRzQHjcSQDrQtttDxqwrFuginlqZRtxkUMCll, mergingValue=null}
Entry Added:EntryEvent{entryEventType=ADDED, member=Member [10.80.2.23]:5702 - 237432e4-7a74-49ec-a2e5-d13ac9a8a41c this, name='my-map', key=YcSjQHklapAKVgZh, oldValue=null, value=QUmnTsqnTzivhROWpHlDujCuMwVnLzYSELwoNgWHkPEzwouL, mergingValue=null}
Entry Added:EntryEvent{entryEventType=ADDED, member=Member [10.80.2.23]:5702 - 237432e4-7a74-49ec-a2e5-d13ac9a8a41c this, name='my-map', key=XeHNRdcizbNZQgZH, oldValue=null, value=SFuZPrNNDbhHCGwAHLQWZZVmTBLvCFcUAawGSKzyAetQOpEi, mergingValue=null}
Entry Added:EntryEvent{entryEventType=ADDED, member=Member [10.80.2.23]:5702 - 237432e4-7a74-49ec-a2e5-d13ac9a8a41c this, name='my-map', key=mcPOBkUEmzBEkgXJ, oldValue=null, value=oTKCqSFoExFHuRKtzUcLjFdPbSPLihVBPfvafiQXppayJzom, mergingValue=null}

Step 6. Clean Up

To clean up the created resources remove the secrets and Hazelcast Custom Resources.

$ kubectl delete secret <external-bucket-secret-name>
$ kubectl delete secret hazelcast-license-key
$ kubectl delete hazelcast hazelcast

See Also