Workflow mit den Cloud-Clientbibliotheken ausführen

Beispielworkflow bereitstellen

Nachdem Sie einen Workflow definiert haben, stellen Sie ihn bereit, um ihn für die Ausführung verfügbar zu machen. Der Bereitstellungsschritt überprüft auch, ob die Quelldatei ausgeführt werden kann.

Der folgende Workflow sendet eine Anfrage an eine öffentliche API und gibt dann die Antwort der API zurück.

1. Erstellen Sie eine Textdatei mit dem Dateinamen myFirstWorkflow.yaml und folgendem Inhalt:

   # This workflow accepts an optional "searchTerm" argument for the Wikipedia API.
   # If no input arguments are provided or "searchTerm" is absent,
   # it will fetch the day of the week in Amsterdam and use it as the search term.
   
   main:
       params: [input]
       steps:
       - validateSearchTermAndRedirectToReadWikipedia:
           switch:
               - condition: '${map.get(input, "searchTerm") != null}'
                 assign:
                   - searchTerm: '${input.searchTerm}'
                 next: readWikipedia
       - getCurrentTime:
           call: http.get
           args:
               url: https://timeapi.io/api/Time/current/zone?timeZone=Europe/Amsterdam
           result: currentTime
       - setFromCallResult:
           assign:
               - searchTerm: '${currentTime.body.dayOfWeek}'
       - readWikipedia:
           call: http.get
           args:
               url: 'https://en.wikipedia.org/w/api.php'
               query:
                   action: opensearch
                   search: '${searchTerm}'
           result: wikiResult
       - returnOutput:
               return: '${wikiResult.body[1]}'

2. Nachdem Sie den Workflow erstellt haben, können Sie ihn bereitstellen, aber nicht den Workflow ausführen:

   gcloud workflows deploy myFirstWorkflow \
       --source=myFirstWorkflow.yaml \
       --service-account=SERVICE_ACCOUNT_NAME@PROJECT_ID.iam.gserviceaccount.com \
       --location=CLOUD_REGION

   Ersetzen Sie CLOUD_REGION durch einen unterstützten Speicherort für den Workflow. Die Standardregion, die in den Codebeispielen verwendet wird, ist us-central1.

Beispielcode abrufen

Sie können den Beispielcode aus GitHub klonen.

1. Klonen Sie das Repository der Beispiel-App auf Ihren lokalen Computer:

   C#

   git clone https://github.com/GoogleCloudPlatform/dotnet-docs-samples.git

   Sie können auch das Beispiel als ZIP-Datei herunterladen und extrahieren.

   Go

   git clone https://github.com/GoogleCloudPlatform/golang-samples.git

   Sie können auch das Beispiel als ZIP-Datei herunterladen und extrahieren.

   Java

   git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git

   Sie können auch das Beispiel als ZIP-Datei herunterladen und extrahieren.

   Node.js

   git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git

   Sie können auch das Beispiel als ZIP-Datei herunterladen und extrahieren.

   Python

   git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git

   Sie können auch das Beispiel als ZIP-Datei herunterladen und extrahieren.

2. Wechseln Sie in das Verzeichnis, das den Workflows-Beispielcode enthält:

   C#

   cd dotnet-docs-samples/workflows/api/Workflow.Samples/

   Go

   cd golang-samples/workflows/executions/

   Java

   cd java-docs-samples/workflows/cloud-client/

   Node.js

   cd nodejs-docs-samples/workflows/quickstart/

   Python

   cd python-docs-samples/workflows/cloud-client/

3. Sehen Sie sich den Beispielcode an: Jede Beispiel-App führt folgende Schritte aus:

   1. Richtet die Cloud-Clientbibliotheken für Workflows ein.
   2. Führt einen Workflow aus.
   3. Fragt die Ausführung des Workflows (mit exponentiellem Backoff) ab, bis die Ausführung beendet ist.
   4. Druckt die Ausführungsergebnisse.

   C#

   
   using Google.Cloud.Workflows.Common.V1;
   using Google.Cloud.Workflows.Executions.V1;
   using System;
   using System.Threading;
   using System.Threading.Tasks;
   
   public class ExecuteWorkflowSample
   {
       /// <summary>
       /// Execute a workflow and return the execution operation.
       /// </summary>
       /// <param name="projectID">Your Google Cloud Project ID.</param>
       /// <param name="locationID">The region where your workflow is located.</param>
       /// <param name="workflowID">Your Workflow ID.</param>
       /// <returns>
       /// An Execute object representing the completed workflow execution.
       /// </returns>
       public async Task<Execution> ExecuteWorkflow(
           string projectId = "YOUR-PROJECT-ID",
           string locationID = "YOUR-LOCATION-ID",
           string workflowID = "YOUR-WORKFLOW-ID")
       {
           // Initialize the client.
           ExecutionsClient client = await ExecutionsClient.CreateAsync();
   
           // Build the parent location path.
           WorkflowName parent = new WorkflowName(projectId, locationID, workflowID);
   
           // Create an execution request.
           CreateExecutionRequest createExecutionRequest = new CreateExecutionRequest
           {
               ParentAsWorkflowName = parent,
           };
   
           // Execute the operation.
           Execution execution = await client.CreateExecutionAsync(createExecutionRequest);
           Console.WriteLine("- Execution started...");
   
           TimeSpan backoffDelay = TimeSpan.FromSeconds(1);
           TimeSpan maxBackoffDelay = TimeSpan.FromSeconds(16);
   
           // Keep polling the state until the execution finishes, using exponential backoff.
           while (execution.State == Execution.Types.State.Active)
           {
               await Task.Delay(backoffDelay);
   
               // Implement exponential backoff by doubling the delay, but limiting it to a practical duration.
               backoffDelay = (backoffDelay < maxBackoffDelay) ? backoffDelay * 2 : maxBackoffDelay;
   
               execution = await client.GetExecutionAsync(execution.Name);
           }
   
           // Print results.
           Console.WriteLine($"Execution finished with state: {execution.State}");
           Console.WriteLine($"Execution results: {execution.Result}");
   
           // Return the fetched execution.
           return execution;
       }
   }

   Go

   import (
   	"context"
   	"fmt"
   	"io"
   	"time"
   
   	workflowexecutions "google.golang.org/api/workflowexecutions/v1"
   )
   
   // Execute a workflow and print the execution results.
   //
   // For more information about Workflows see:
   // https://cloud.google.com/workflows/docs/overview
   func executeWorkflow(w io.Writer, projectID, workflowID, locationID string) error {
   	// TODO(developer): Uncomment and update the following lines:
   	// projectID := "YOUR_PROJECT_ID"
   	// workflowID := "YOUR_WORKFLOW_ID"
   	// locationID := "YOUR_LOCATION_ID"
   
   	ctx := context.Background()
   
   	// Construct the location path.
   	parent := fmt.Sprintf("projects/%s/locations/%s/workflows/%s", projectID, locationID, workflowID)
   
   	// Create execution client.
   	client, err := workflowexecutions.NewService(ctx)
   	if err != nil {
   		return fmt.Errorf("workflowexecutions.NewService error: %w", err)
   	}
   
   	// Get execution service.
   	service := client.Projects.Locations.Workflows.Executions
   
   	// Build and run the new workflow execution.
   	res, err := service.Create(parent, &workflowexecutions.Execution{}).Do()
   	if err != nil {
   		return fmt.Errorf("service.Create.Do error: %w", err)
   	}
   	fmt.Fprintln(w, "- Execution started...")
   
   	// Set initial value for backoff delay in one second.
   	backoffDelay := time.Second
   
   	for res.State == "ACTIVE" {
   		time.Sleep(backoffDelay)
   
   		// Request the updated state for the execution.
   		getReq := service.Get(res.Name)
   		res, err = getReq.Do()
   		if err != nil {
   			return fmt.Errorf("getReq error: %w", err)
   		}
   
   		// Double the delay to provide exponential backoff (capped at 16 seconds).
   		if backoffDelay < time.Second*16 {
   			backoffDelay *= 2
   		}
   	}
   
   	fmt.Fprintf(w, "Execution finished with state: %s\n", res.State)
   	fmt.Fprintf(w, "Execution results: %s\n", res.Result)
   
   	return nil
   }
   

   Java

   
   import com.google.cloud.workflows.executions.v1.CreateExecutionRequest;
   import com.google.cloud.workflows.executions.v1.Execution;
   import com.google.cloud.workflows.executions.v1.ExecutionsClient;
   import com.google.cloud.workflows.executions.v1.WorkflowName;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   
   public class ExecuteWithoutArguments {
     public static void main(String[] args)
         throws IOException, InterruptedException, ExecutionException {
       String projectId = "your-project-id";
       String location = "your-location"; // For example: us-central1
       String workflowId = "your-workflow-id";
   
       executeWorkflowWithoutArguments(projectId, location, workflowId);
     }
   
     public static void executeWorkflowWithoutArguments(
         String projectId, String location, String workflowId)
         throws IOException, InterruptedException, ExecutionException {
       try (ExecutionsClient executionsClient = ExecutionsClient.create()) {
         WorkflowName parent = WorkflowName.of(projectId, location, workflowId);
   
         CreateExecutionRequest executionRequest =
             CreateExecutionRequest.newBuilder()
                 .setParent(parent.toString())
                 .setExecution(Execution.newBuilder().build())
                 .build();
   
         Execution executionCreated = executionsClient.createExecution(executionRequest);
   
         System.out.println("Created execution: " + executionCreated.getName());
   
         // Wait for execution to finish using exponential backoff
         long backoffDelay = 1_000;
         Execution execution;
         System.out.println("Poll for result...");
         while (true) {
           execution = executionsClient.getExecution(executionCreated.getName());
   
           // Check if execution finished
           if (execution.getState() != Execution.State.ACTIVE) {
             break;
           }
   
           // Wait using exponential backoff
           System.out.println("- Waiting for results...");
           Thread.sleep(backoffDelay);
           backoffDelay *= 2;
         }
   
         System.out.println("Execution finished with state: " + execution.getState().name());
         System.out.println("Execution results: " + execution.getResult());
       }
     }
   }

   Node.js

   const {ExecutionsClient} = require('@google-cloud/workflows');
   const client = new ExecutionsClient();
   /**
    * TODO(developer): Uncomment these variables before running the sample.
    */
   // const projectId = 'my-project';
   // const location = 'us-central1';
   // const workflow = 'myFirstWorkflow';
   // const searchTerm = '';
   
   /**
    * Executes a Workflow and waits for the results with exponential backoff.
    * @param {string} projectId The Google Cloud Project containing the workflow
    * @param {string} location The workflow location
    * @param {string} workflow The workflow name
    * @param {string} searchTerm Optional search term to pass to the Workflow as a runtime argument
    */
   async function executeWorkflow(projectId, location, workflow, searchTerm) {
     /**
      * Sleeps the process N number of milliseconds.
      * @param {Number} ms The number of milliseconds to sleep.
      */
     function sleep(ms) {
       return new Promise(resolve => {
         setTimeout(resolve, ms);
       });
     }
     const runtimeArgs = searchTerm ? {searchTerm: searchTerm} : {};
     // Execute workflow
     try {
       const