Quickstart: Create a workflow using Terraform

Create a Terraform configuration file

Create a terraform configuration file called main.tf to include the Google Cloud resources used in this project.

1. Create a directory:

   mkdir terraform

2. Go to the terraform directory:

   cd terraform

3. Add a new file, main.tf, to the directory:

   nano main.tf

4. Add the following resources to the main.tf file:
   1. Assign the ID of the project:

      provider "google" {
       project = "PROJECT_ID"
      }
      

      Replace PROJECT_ID with your project's ID.

   2. Enable the Workflows API:
      terraform/basic/main.tf

      View on GitHub

      resource "google_project_service" "workflows" {
        service            = "workflows.googleapis.com"
        disable_on_destroy = false
      }

   3. Create a service account for the workflow:
      terraform/basic/main.tf

      View on GitHub

      resource "google_service_account" "workflows_service_account" {
        account_id   = "sample-workflows-sa"
        display_name = "Sample Workflows Service Account"
      }

   4. Define and deploy the workflow:
      terraform/basic/main.tf

      View on GitHub

      resource "google_workflows_workflow" "workflows_example" {
        name            = "sample-workflow"
        region          = "us-central1"
        description     = "A sample workflow"
        service_account = google_service_account.workflows_service_account.id
        source_contents = <<-EOF
        # This is a sample workflow, feel free to replace it with your source code
        #
        # This workflow does the following:
        # - reads current time and date information from an external API and stores
        #   the response in CurrentDateTime variable
        # - retrieves a list of Wikipedia articles related to the day of the week
        #   from CurrentDateTime
        # - returns the list of articles as an output of the workflow
        # FYI, In terraform you need to escape the $$ or it will cause errors.
      
        - getCurrentTime:
            call: http.get
            args:
                url: https://us-central1-workflowsample.cloudfunctions.net/datetime
            result: CurrentDateTime
        - readWikipedia:
            call: http.get
            args:
                url: https://en.wikipedia.org/w/api.php
                query:
                    action: opensearch
                    search: $${CurrentDateTime.body.dayOfTheWeek}
            result: WikiResult
        - returnOutput:
            return: $${WikiResult.body[1]}
      EOF
      
        depends_on = [google_project_service.workflows]
      }

Deploy and execute the workflow

Deploy your resources with Terraform to create a workflow.

1. Initialize Terraform in the directory:

   terraform init
   

2. Check that the changes you propose with Terraform match the expected plan:

   terraform plan
   

   You can ignore the note regarding not using the -out option.

3. Create the workflow:

   terraform apply
   

4. At the Enter a value prompt, enter yes to proceed with the creation of resources.
5. Confirm that a workflow is created:

   gcloud workflows list --location us-central1
   

   The output should be similar to the following:

   NAME                                                                          STATE   REVISION_ID  UPDATE_TIME
   projects/project-name/locations/us-central1/workflows/sample-workflow         ACTIVE  000001-f9a   2021-06-24T13:38:58.353765906Z
   

6. Optionally, you can execute the workflow:

   gcloud workflows execute sample-workflow