Function Mesh provides a tool, which is used to migrate Pulsar Functions from the function worker of a Pulsar cluster to Function Mesh. The tool encapsulates the pulsarctl configurations, which is used to transfer Pulsar configurations.

Prerequisites

• Go 1.15 or higher

Steps

1. Build the tool.

   1. Define a pulsarctl.properties configuration file for the tool.

      webServiceUrl=http://localhost:8080
      tlsAllowInsecureConnection=false
      tlsTrustCertsFilePath=
      brokerServiceUrl=
      authParams=
      authPlugin=
      tlsEnableHostnameVerification=false
      

   2. Declare environment variables PULSAR_CLIENT_CONF.

      export PULSAR_CLIENT_CONF=/PATH/pulsarctl.properties
      

      Replace the PATH variable with the absolute path to the pulsarctl.properties configuration file.

   3. Build the tool from the source code.

      git clone https://github.com/streamnative/function-mesh
      cd function-mesh/tools
      go build
      

2. Generate the YAML file which is used to create the function in Function Mesh.

   ./tools
   

   The generated YAML file adopts a structure as below, where the public, default, and function-sample represent the tenant name, namespace name, and function name respectively.

   functions
   └── public
       └── default
           └── function-sample.yaml
   

   This is an example of the generated YAML file.

    ```yaml
    apiVersion: compute.functionmesh.io/v1alpha1
    kind: Function
    metadata:
      creationTimestamp: null
      name: function-sample
      namespace: default
    spec:
      autoAck: true
      className: org.apache.pulsar.functions.api.examples.ExclamationFunction
      cleanupSubscription: true
      clusterName: standalone
      funcConfig:
        PublishTopic: test_result
      input:
        sourceSpecs:
        test_src: {}
        topics:
        - test_src
      # other function config
    ```
   

After the YAML file is generated, you can use the kubectl apply -f command to create the function.

kubectl apply -f /path/to/function-sample.yaml