How can I run create Dataproc cluster, run job, de

Question

I would like to start a Dataproc job in response to log files arriving in GCS bucket. I also do not want to keep a persistent cluster running as new log files arrive only several times a day and it would be idle most of the time.

Answer 1

I can use WorkflowTemplate API to manage the cluster lifecycle for me. With Dataproc Workflows I don't have to poll for either cluster to be created, or job created, or do any error handling.

Here's my Cloud Function. Set to Cloud Storage bucket to trigger on Finalize/Create event:

index.js:

exports.startWorkflow = (event, callback) => {

  const {google} = require('googleapis');

  const region = 'global'
  const zone = 'us-central1-a'
  const clusterName = 'my-cluster'

  const file = event.data;
  console.log("Event: ", file);

  if (!file.name) {
    throw "Skipped processing file!";
  }

  const queryFileUri = "gs://" + file.bucket + "/" + file.name

  console.log("Creating auth client: ");
  google.auth.getApplicationDefault(
    (err, authClient, projectId) => {
      if (authClient.createScopedRequired && authClient.createScopedRequired()) {
        authClient = authClient.createScoped([
          'https://www.googleapis.com/auth/cloud-platform',
          'https://www.googleapis.com/auth/userinfo.email'
        ]);
      }

      const request = {
        parent: "projects/" + projectId + "/regions/" + region,
        resource: {
          "placement": {
            "managedCluster": {
              "clusterName": clusterName,
              "config": {
                "gceClusterConfig": {
                  "zoneUri" : zone, // Can be omitted if using regional endpoint (like us-central1-a, not global)
                }
              }
            }
          },
          "jobs": [
            {
              "stepId": "step1",
              "pigJob": {
                "queryFileUri": queryFileUri,
              },
              "prerequisiteStepIds": [],
            }
          ]
        }
      };

      const dataproc = google.dataproc({ version: 'v1beta2', auth: authClient});
      dataproc.projects.regions.workflowTemplates.instantiateInline(
        request, (err, result) => {
          if (err) {
            throw err;
          }
          console.log(result);
          callback();
        });
    });
};

Make sure to set Function to Execute to startWorkflow.

package.json

{
  "name": "dataproc-workflow",
  "version": "1.0.0",
  "dependencies":{ "googleapis": "30.0.0"}
}