Run Java Functions

After packaging your Pulsar function, you can submit your Pulsar function to a Pulsar cluster. This document describes how to submit a Java function through a function CRD. You can use the image field to specify the runner image for creating the Java function. You can also specify the location where the package or the image is stored.

1. Define a Java function by using a YAML file and save the YAML file.

   • This example shows how to publish a java-function-sample function to a Pulsar cluster by using a JAR package called function://my-tenant/my-ns/my-function@0.1.

     apiVersion: compute.functionmesh.io/v1alpha1
     kind: Function
     metadata:
       name: java-function-sample
       namespace: default
     spec:
       image: streamnative/pulsar-functions-java-runner:2.7.1 # using java function runner
       className: exclamation_function.ExclamationFunction
       forwardSourceMessageProperty: true
       maxPendingAsyncRequests: 1000
       replicas: 1
       maxReplicas: 5
       logTopic: persistent://public/default/logging-function-logs
       input:
         topics:
         - persistent://public/default/java-function-input-topic
         typeClassName: java.lang.String
       output:
         topic: persistent://public/default/java-function-output-topic
         typeClassName: java.lang.String
       pulsar:
         pulsarConfig: "test-pulsar"
       java:
         extraDependenciesDir: random-dir/
         jar: my-function.jar # the package will download as this filename.
         jarLocation: function://my-tenant/my-ns/my-function@0.1 # function package URL

   • This example shows how to publish a java-function-sample function to a Pulsar cluster by using a Docker image.

     apiVersion: compute.functionmesh.io/v1alpha1
     kind: Function
     metadata:
       name: java-function-sample
       namespace: default
     spec:
       image: streamnative/example-function-image:latest # using function image here
       className: exclamation_function.ExclamationFunction
       forwardSourceMessageProperty: true
       maxPendingAsyncRequests: 1000
       replicas: 1
       maxReplicas: 5
       logTopic: persistent://public/default/logging-function-logs
       input:
         topics:
         - persistent://public/default/java-function-input-topic
         typeClassName: java.lang.String
       output:
         topic: persistent://public/default/java-function-output-topic
         typeClassName: java.lang.String
       pulsar:
         pulsarConfig: "test-pulsar"
       java:
         extraDependenciesDir: random-dir/
         jar: /pulsar/example-function.jar # the package location in image
         jarLocation: "" # leave empty since we will not download package from Pulsar Packages

• This example shows how to publish a java-exclamation-function function to a Pulsar cluster by using the self-built image java-exclamation-function:v1.

  apiVersion: compute.functionmesh.io/v1alpha1
  kind: Function
  metadata:
    name: java-exclamation-function
    namespace: default
  spec:
    image: java-exclamation-function:v1
    className: org.example.ExclamationFunction
    forwardSourceMessageProperty: true
    maxPendingAsyncRequests: 1000
    replicas: 1
    maxReplicas: 5
    logTopic: persistent://public/default/logging-function-logs
    input:
      topics:
      - persistent://public/default/input-java-topic
      typeClassName: java.lang.String
    output:
      topic: persistent://public/default/output-java-topic
      typeClassName: java.lang.String
    resources:
      requests:
        cpu: "0.1"
        memory: 1G
      limits:
        cpu: "0.2"
        memory: 1.1G
    secretsMap:
      "name":
          path: "test-secret"
          key: "username"
      "pwd":
          path: "test-secret"
          key: "password"
    pulsar:
      pulsarConfig: "test-pulsar"
    java:
      jar: /pulsar/java-function-1.0-SNAPSHOT.jar
    clusterName: test
    autoAck: true
  ---
  apiVersion: v1
  kind: ConfigMap
  metadata:
    name: test-pulsar
  data:
    webServiceURL: http://sn-platform-pulsar-broker.default.svc.cluster.local:8080
    brokerServiceURL: pulsar://sn-platform-pulsar-broker.default.svc.cluster.local:6650
  ---
  apiVersion: v1
  data:
    username: YWRtaW4=
    password: MWYyZDFlMmU2N2Rm
  kind: Secret
  metadata:
    name: test-secret
  type: Opaque

2. Apply the YAML file to create the Java function.

   kubectl apply -f /path/to/YAML/file

3. Check whether the Java function is created successfully.

   kubectl get all