Invoke a Google Cloud service using a connector

Workflows publishes connectors to make it easier to access other Google Cloud APIs within a workflow, and to integrate your workflows with those Google Cloud products. For example, you can use connectors to publish Pub/Sub messages, read or write data to a Firestore database, or retrieve authentication keys from Secret Manager. For a detailed reference of available connectors, see the Connectors reference.

Connectors simplify calling services because they handle the formatting of requests for you, providing methods and arguments so that you don't need to know the details of a Google Cloud API. To learn more about authentication, and behavior during retries and long-running operations, see Understand connectors.

Invoke a connector call

Similar to invoking an HTTP endpoint, a connector call requires call and args fields. You can specify a timeout value and polling policy using the connector_params block:

- STEP_NAME:
    call: CONNECTOR
    args:
        ARG: ARG_VALUE
        [...]
        body:
            KEY:KEY_VALUE
            [...]
        connector_params:
            timeout: TIMEOUT_IN_SECONDS
            polling_policy:
                initial_delay: INITIAL_DELAY_IN_SECONDS
                multiplier: MULTIPLIER_VALUE
                max_delay: MAX_DELAY_IN_SECONDS
            skip_polling: SKIP_POLLING_SWITCH 
            scopes:  OAUTH2_SCOPE 
    result: RESPONSE_VALUE

Replace the following:

• STEP_NAME: the name of the step.
• CONNECTOR (required): the connector method in the form googleapis.gcp_service.version.resource.operation. For example, googleapis.bigquery.v2.tables.get.
• ARG and ARG_VALUE (required): each connector call requires different arguments.
• KEY and KEY_VALUE (optional): fields to supply input to the API.
• Connector-specific parameters (optional):
  • TIMEOUT_IN_SECONDS: time in seconds. The end-to-end duration the connector call is allowed to run for before throwing a timeout exception. The default value is 1800 and this should be the maximum for connector methods that are not long-running operations. Otherwise, for long-running operations, the maximum timeout for a connector call is 31536000 seconds (one year).
  • INITIAL_DELAY_IN_SECONDS: polling policy parameter with a default value of 1.0. Only applies to long-running operation calls.
  • MULTIPLIER_VALUE: polling policy parameter with a default value of 1.25. Only applies to long-running operation calls.
  • MAX_DELAY_IN_SECONDS: polling policy parameter with a default value of 60.0. Only applies to long-running operation calls.
  • SKIP_POLLING_SWITCH: if set to True, the connector invocation call is non-blocking if the initial request to manage or update the resource succeeds (usually HTTP POST, HTTP UPDATE, or HTTP DELETE). If the initial request is not successful, retries might occur. Polling of status (HTTP GET requests that follow the initial request) is skipped for the long-running operation after the initial request completes. The default value is False.
  • OAUTH2_SCOPE: OAuth2 scopes to pass to the Google API. Can be a string, list of strings, space-separated string, or comma-separated string.
• RESPONSE_VALUE (optional): variable name where the result of a connector call invocation step is stored.

Example

The following workflow demonstrates using both the Cloud Storage API connector and the Cloud Translation API connector to translate two files to French and Spanish, saving the results in a Cloud Storage bucket.

main:
  steps:
  - init:
      assign:
      - projectId: ${sys.get_env("GOOGLE_CLOUD_PROJECT_ID")}
      - location: ${sys.get_env("GOOGLE_CLOUD_LOCATION")}
      - inputBucketName: ${projectId + "-input-files"}
      - outputBucketName: ${projectId + "-output-files-" + string(int(sys.now()))}
  - createOutputBucket:
        call: googleapis.storage.v1.buckets.insert
        args:
          project: ${projectId}
          body:
            name: ${outputBucketName}
  - batchTranslateText:
      call: googleapis.translate.v3beta1.projects.locations.batchTranslateText
      args:
          parent: ${"projects/" + projectId + "/locations/" + location}
          body:
              inputConfigs:
                gcsSource:
                  inputUri: ${"gs://" + inputBucketName + "/*"}
              outputConfig:
                  gcsDestination:
                    outputUriPrefix: ${"gs://" + outputBucketName + "/"}
              sourceLanguageCode: "en"
              targetLanguageCodes: ["es", "fr"]
      result: batchTranslateTextResult

What's next

• Tutorial: Run a batch translation using the Cloud Translation connector