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Executar um fluxo de trabalho usando bibliotecas de cliente

É possível executar um fluxo de trabalho e conferir os resultados da execução usando uma biblioteca de cliente.

Para mais informações sobre como instalar as bibliotecas de cliente e configurar o ambiente de desenvolvimento, consulte a Visão geral das bibliotecas de cliente do Workflows.

Antes de começar

As restrições de segurança definidas pela sua organização podem impedir que você conclua as etapas a seguir. Para informações sobre solução de problemas, consulte Desenvolver aplicativos em um ambiente restrito do Google Cloud.

O exemplo a seguir pressupõe que você já tenha implantado o fluxo de trabalho, myFirstWorkflow. Se ainda não tiver feito isso, implante-o agora usando o console do Google Cloud ou a Google Cloud CLI.
Faça o download e instale a ferramenta de gerenciamento de código-fonte Git.

Acessar o exemplo de código

Clone o repositório do aplicativo de amostra na máquina local:
Java
```
git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git
```
Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.
Node.js
```
git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git
```
Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.
Python
```
git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git
```
Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

Altere para o diretório que contém o código de amostra do Workflows:

Java

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

Node.js

cd nodejs-docs-samples/workflows/quickstart/

Python

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

Confira o código de amostra:

Java

// Imports the Google Cloud client library

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 WorkflowsQuickstart {

  private static final String PROJECT = System.getenv("GOOGLE_CLOUD_PROJECT");
  private static final String LOCATION = System.getenv().getOrDefault("LOCATION", "us-central1");
  private static final String WORKFLOW =
      System.getenv().getOrDefault("WORKFLOW", "myFirstWorkflow");

  public static void main(String... args)
      throws IOException, InterruptedException, ExecutionException {
    if (PROJECT == null) {
      throw new IllegalArgumentException(
          "Environment variable 'GOOGLE_CLOUD_PROJECT' is required to run this quickstart.");
    }
    workflowsQuickstart(PROJECT, LOCATION, WORKFLOW);
  }

  private static volatile boolean finished;

  public static void workflowsQuickstart(String projectId, String location, String workflow)
      throws IOException, InterruptedException, ExecutionException {
    // Initialize client that will be used to send requests. This client only needs
    // to be created once, and can be reused for multiple requests. After completing all of your
    // requests, call the "close" method on the client to safely clean up any remaining background
    // resources.
    try (ExecutionsClient executionsClient = ExecutionsClient.create()) {
      // Construct the fully qualified location path.
      WorkflowName parent = WorkflowName.of(projectId, location, workflow);

      // Creates the execution object.
      CreateExecutionRequest request =
          CreateExecutionRequest.newBuilder()
              .setParent(parent.toString())
              .setExecution(Execution.newBuilder().build())
              .build();
      Execution response = executionsClient.createExecution(request);

      String executionName = response.getName();
      System.out.printf("Created execution: %s%n", executionName);

      long backoffTime = 0;
      long backoffDelay = 1_000; // Start wait with delay of 1,000 ms
      final long backoffTimeout = 10 * 60 * 1_000; // Time out at 10 minutes
      System.out.println("Poll for results...");

      // Wait for execution to finish, then print results.
      while (!finished && backoffTime < backoffTimeout) {
        Execution execution = executionsClient.getExecution(executionName);
        finished = execution.getState() != Execution.State.ACTIVE;

        // If we haven't seen the results yet, wait.
        if (!finished) {
          System.out.println("- Waiting for results");
          Thread.sleep(backoffDelay);
          backoffTime += backoffDelay;
          backoffDelay *= 2; // Double the delay to provide exponential backoff.
        } else {
          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 createExecutionRes = await client.createExecution({
      parent: client.workflowPath(projectId, location, workflow),
      execution: {
        // Runtime arguments can be passed as a JSON string
        argument: JSON.stringify(runtimeArgs),
      },
    });
    const executionName = createExecutionRes[0].name;
    console.log(`Created execution: ${executionName}`);

    // Wait for execution to finish, then print results.
    let executionFinished = false;
    let backoffDelay = 1000; // Start wait with delay of 1,000 ms
    console.log('Poll every second for result...');
    while (!executionFinished) {
      const [execution] = await client.getExecution({
        name: executionName,
      });
      executionFinished = execution.state !== 'ACTIVE';

      // If we haven't seen the result yet, wait a second.
      if (!executionFinished) {
        console.log('- Waiting for results...');
        await sleep(backoffDelay);
        backoffDelay *= 2; // Double the delay to provide exponential backoff.
      } else {
        console.log(`Execution finished with state: ${execution.state}`);
        console.log(execution.result);
        return execution.result;
      }
    }
  } catch (e) {
    console.error(`Error executing workflow: ${e}`);
  }
}

executeWorkflow(projectId, location, workflowName, searchTerm).catch(err => {
  console.error(err.message);
  process.exitCode = 1;
});

Python

import time

from google.cloud import workflows_v1
from google.cloud.workflows import executions_v1
from google.cloud.workflows.executions_v1 import Execution
from google.cloud.workflows.executions_v1.types import executions


def execute_workflow(
    project: str, location: str = "us-central1", workflow: str = "myFirstWorkflow"
) -> Execution:
    """Execute a workflow and print the execution results.

    A workflow consists of a series of steps described using the Workflows syntax, and can be written in either YAML or JSON.

    Args:
        project: The Google Cloud project id which contains the workflow to execute.
        location: The location for the workflow
        workflow: The ID of the workflow to execute.

    Returns:
        The execution response.
    """
    # Set up API clients.
    execution_client = executions_v1.ExecutionsClient()
    workflows_client = workflows_v1.WorkflowsClient()
    # Construct the fully qualified location path.
    parent = workflows_client.workflow_path(project, location, workflow)

    # Execute the workflow.
    response = execution_client.create_execution(request={"parent": parent})
    print(f"Created execution: {response.name}")

    # Wait for execution to finish, then print results.
    execution_finished = False
    backoff_delay = 1  # Start wait with delay of 1 second
    print("Poll for result...")
    while not execution_finished:
        execution = execution_client.get_execution(request={"name": response.name})
        execution_finished = execution.state != executions.Execution.State.ACTIVE

        # If we haven't seen the result yet, wait a second.
        if not execution_finished:
            print("- Waiting for results...")
            time.sleep(backoff_delay)
            # Double the delay to provide exponential backoff.
            backoff_delay *= 2
        else:
            print(f"Execution finished with state: {execution.state.name}")
            print(f"Execution results: {execution.result}")
            return execution

O programa faz o seguinte:

Configura as bibliotecas de cliente do Cloud para o Workflows.
Executa um fluxo de trabalho.
Pesquisa a execução do fluxo de trabalho (usando a espera exponencial) até que ela seja encerrada.
Exibe os resultados da execução.

Executar a amostra

Para executar a amostra, primeiro instale as dependências:
Java
```
mvn compile
```
Node.js
```
npm install
```
Python
```
pip3 install -r requirements.txt
```

Execute o script:

Java

GOOGLE_CLOUD_PROJECT=PROJECT_ID LOCATION=CLOUD_REGION WORKFLOW=WORKFLOW_NAME mvn compile exec:java -Dexec.mainClass=com.example.workflows.WorkflowsQuickstart

Node.js

node . PROJECT_ID CLOUD_REGION WORKFLOW_NAME

Python

GOOGLE_CLOUD_PROJECT=PROJECT_ID LOCATION=CLOUD_REGION WORKFLOW=WORKFLOW_NAME python3 main.py

Substitua:

PROJECT_ID: (obrigatório) o ID do projeto do Google Cloud
CLOUD_REGION: o local do fluxo de trabalho (padrão: us-central1)
WORKFLOW_NAME: o ID do fluxo de trabalho (padrão: myFirstWorkflow)

O resultado será assim:

Execution finished with state: SUCCEEDED
["Sunday","Sunday in the Park with George","Sunday shopping","Sunday Bloody Sunday","Sunday Times Golden Globe Race","Sunday All Stars","Sunday Night (South Korean TV series)","Sunday Silence","Sunday Without God","Sunday Independent (Ireland)"]

Transmitir dados em uma solicitação de execução

Dependendo da linguagem da biblioteca de cliente, também é possível transmitir um argumento de ambiente de execução em uma solicitação de execução.

Por exemplo, usando JavaScript:

// Execute workflow
try {
  const createExecutionRes = await client.createExecution({
    parent: client.workflowPath(projectId, location, workflow),
    execution: {
      argument: JSON.stringify({"searchTerm": "Friday"})
    }
});
const executionName = createExecutionRes[0].name;

Ou, usando Java:

// Creates the execution object.
CreateExecutionRequest request =
    CreateExecutionRequest.newBuilder()
        .setParent(parent.toString())
        .setExecution(Execution.newBuilder().setArgument("{\"searchTerm\":\"Friday\"}").build())
        .build();

Para mais informações sobre como transmitir argumentos de ambiente de execução, consulte Transmitir argumentos de ambiente de execução em uma solicitação de execução.

Limpar

Para evitar cobranças na conta do Google Cloud pelos recursos usados nesta página, siga estas etapas.

No console do Google Cloud, abra a página Workflows.

Acessar fluxos de trabalho
Na lista de fluxos de trabalho, clique em um fluxo para acessar a página Detalhes do fluxo de trabalho.
Clique em Excluir.
Digite o nome do fluxo de trabalho e clique em Confirmar.

Executar um fluxo de trabalho usando bibliotecas de cliente

Antes de começar

Acessar o exemplo de código

Java

Node.js

Python

Java

Node.js

Python

Java

Node.js

Python

Executar a amostra

Java

Node.js

Python

Java

Node.js

Python

Transmitir dados em uma solicitação de execução

Limpar

A seguir