Como testar funções em segundo plano

Há dois tipos distintos de Funções do Cloud: funções HTTP e funções em segundo plano. Cada tipo tem requisitos de teste próprios.

A estrutura de teste das funções depende dos recursos do Google Cloud que elas usam. Por sua vez, o uso do recurso da função depende de como essa ela é acionada.

Este documento mostra como testar as funções do Cloud em segundo plano. Consulte Como testar as funções HTTP para obter informações sobre como testar as funções HTTP.

Funções acionadas pelo Pub/Sub

Os testes da função acionada pelo Pub/Sub são estruturados de maneira diferente dependendo de onde a função testada está em execução.

Veja o exemplo de uma função acionada pelo Pub/Sub com "Hello, World"

Node.js

/**
 * Background Cloud Function to be triggered by Pub/Sub.
 * This function is exported by index.js, and executed when
 * the trigger topic receives a message.
 *
 * @param {object} message The Pub/Sub message.
 * @param {object} context The event metadata.
 */
exports.helloPubSub = (message, context) => {
  const name = message.data
    ? Buffer.from(message.data, 'base64').toString()
    : 'World';

  console.log(`Hello, ${name}!`);
};

Python

def hello_pubsub(event, context):
    """Background Cloud Function to be triggered by Pub/Sub.
    Args:
         event (dict):  The dictionary with data specific to this type of
         event. The `data` field contains the PubsubMessage message. The
         `attributes` field will contain custom attributes if there are any.
         context (google.cloud.functions.Context): The Cloud Functions event
         metadata. The `event_id` field contains the Pub/Sub message ID. The
         `timestamp` field contains the publish time.
    """
    import base64

    print("""This Function was triggered by messageId {} published at {}
    """.format(context.event_id, context.timestamp))

    if 'data' in event:
        name = base64.b64decode(event['data']).decode('utf-8')
    else:
        name = 'World'
    print('Hello {}!'.format(name))

Go


// Package helloworld provides a set of Cloud Functions samples.
package helloworld

import (
	"context"
	"log"
)

// PubSubMessage is the payload of a Pub/Sub event.
type PubSubMessage struct {
	Data []byte `json:"data"`
}

// HelloPubSub consumes a Pub/Sub message.
func HelloPubSub(ctx context.Context, m PubSubMessage) error {
	name := string(m.Data) // Automatically decoded from base64.
	if name == "" {
		name = "World"
	}
	log.Printf("Hello, %s!", name)
	return nil
}

Java


import com.google.cloud.functions.BackgroundFunction;
import com.google.cloud.functions.Context;
import functions.eventpojos.PubSubMessage;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.logging.Level;
import java.util.logging.Logger;

public class HelloPubSub implements BackgroundFunction<PubSubMessage> {
  private static final Logger logger = Logger.getLogger(HelloPubSub.class.getName());

  @Override
  public void accept(PubSubMessage message, Context context) {
    String name = "world";
    if (message != null && message.getData() != null) {
      name = new String(
          Base64.getDecoder().decode(message.getData().getBytes(StandardCharsets.UTF_8)),
          StandardCharsets.UTF_8);
    }
    logger.info(String.format("Hello %s!", name));
    return;
  }
}

Testes de unidade

Veja os testes de unidade da função acima acionada pelo Pub/Sub:

Node.js

const assert = require('assert');
const uuid = require('uuid');
const sinon = require('sinon');

const {helloPubSub} = require('..');

const stubConsole = function () {
  sinon.stub(console, `error`);
  sinon.stub(console, `log`);
};

const restoreConsole = function () {
  console.log.restore();
  console.error.restore();
};

beforeEach(stubConsole);
afterEach(restoreConsole);

it('helloPubSub: should print a name', () => {
  // Create mock Pub/Sub event
  const name = uuid.v4();
  const event = {
    data: Buffer.from(name).toString('base64'),
  };

  // Call tested function and verify its behavior
  helloPubSub(event);
  assert.ok(console.log.calledWith(`Hello, ${name}!`));
});

Python

import base64

import mock

import main

mock_context = mock.Mock()
mock_context.event_id = '617187464135194'
mock_context.timestamp = '2019-07-15T22:09:03.761Z'

def test_print_hello_world(capsys):
    data = {}

    # Call tested function
    main.hello_pubsub(data, mock_context)
    out, err = capsys.readouterr()
    assert 'Hello World!' in out

def test_print_name(capsys):
    name = 'test'
    data = {'data': base64.b64encode(name.encode())}

    # Call tested function
    main.hello_pubsub(data, mock_context)
    out, err = capsys.readouterr()
    assert 'Hello {}!\n'.format(name) in out

Go


package helloworld

import (
	"context"
	"io/ioutil"
	"log"
	"os"
	"testing"
)

func TestHelloPubSub(t *testing.T) {
	tests := []struct {
		data string
		want string
	}{
		{want: "Hello, World!\n"},
		{data: "Go", want: "Hello, Go!\n"},
	}
	for _, test := range tests {
		r, w, _ := os.Pipe()
		log.SetOutput(w)
		originalFlags := log.Flags()
		log.SetFlags(log.Flags() &^ (log.Ldate | log.Ltime))

		m := PubSubMessage{
			Data: []byte(test.data),
		}
		HelloPubSub(context.Background(), m)

		w.Close()
		log.SetOutput(os.Stderr)
		log.SetFlags(originalFlags)

		out, err := ioutil.ReadAll(r)
		if err != nil {
			t.Fatalf("ReadAll: %v", err)
		}
		if got := string(out); got != test.want {
			t.Errorf("HelloPubSub(%q) = %q, want %q", test.data, got, test.want)
		}
	}
}

Java


import static com.google.common.truth.Truth.assertThat;

import com.google.common.testing.TestLogHandler;
import functions.eventpojos.PubSubMessage;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.logging.Logger;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 * Unit tests for main.java.com.example.functions.helloworld.HelloPubSub.
 */
@RunWith(JUnit4.class)
public class HelloPubSubTest {

  private HelloPubSub sampleUnderTest;
  private static final Logger logger = Logger.getLogger(HelloPubSub.class.getName());

  private static final TestLogHandler LOG_HANDLER = new TestLogHandler();

  @Before
  public void setUp() {
    sampleUnderTest = new HelloPubSub();
    logger.addHandler(LOG_HANDLER);
    LOG_HANDLER.clear();
  }

  @Test
  public void helloPubSub_shouldPrintName() {
    PubSubMessage pubSubMessage = new PubSubMessage();
    pubSubMessage.setData(Base64.getEncoder().encodeToString(
        "John".getBytes(StandardCharsets.UTF_8)));
    sampleUnderTest.accept(pubSubMessage, null);

    String logMessage = LOG_HANDLER.getStoredLogRecords().get(0).getMessage();
    assertThat("Hello John!").isEqualTo(logMessage);
  }

  @Test
  public void helloPubSub_shouldPrintHelloWorld() {
    PubSubMessage pubSubMessage = new PubSubMessage();
    sampleUnderTest.accept(pubSubMessage, null);

    String logMessage = LOG_HANDLER.getStoredLogRecords().get(0).getMessage();
    assertThat("Hello world!").isEqualTo(logMessage);
  }
}

Faça os testes de unidade com este comando:

Node.js

mocha test/sample.unit.pubsub.test.js --exit

Python

pytest sample_pubsub_test.py

Go

go test -v ./hello_pubsub_test.go

Java

mvn clean verify

Testes de integração

Veja os testes de integração da função acima acionada pelo Pub/Sub:

Node.js

const assert = require('assert');
const execPromise = require('child-process-promise').exec;
const path = require('path');
const requestRetry = require('requestretry');
const uuid = require('uuid');

const cwd = path.join(__dirname, '..');

  it('helloPubSub: should print a name', async () => {
    const name = uuid.v4();
    const PORT = 8088; // Each running framework instance needs a unique port

    const encodedName = Buffer.from(name).toString('base64');
    const pubsubMessage = {data: {data: encodedName}};

    // exec's 'timeout' param won't kill children of "shim" /bin/sh process
    // Workaround: include "& sleep <TIMEOUT>; kill $!" in executed command
    const proc = execPromise(
      `functions-framework --target=helloPubSub --signature-type=event --port=${PORT} & sleep 1; kill $!`,
      {shell: true, cwd}
    );

    // Send HTTP request simulating Pub/Sub message
    // (GCF translates Pub/Sub messages to HTTP requests internally)
    const response = await requestRetry({
      url: `http://localhost:${PORT}/`,
      method: 'POST',
      body: pubsubMessage,
      retryDelay: 200,
      json: true,
    });

    assert.strictEqual(response.statusCode, 204);

    // Wait for the functions framework to stop
    const {stdout} = await proc;

    assert(stdout.includes(`Hello, ${name}!`));
  });
});

Python

import base64
import os
import subprocess
import uuid

import requests
from requests.packages.urllib3.util.retry import Retry

def test_print_name():
    name = str(uuid.uuid4())
    port = 8088  # Each running framework instance needs a unique port

    encoded_name = base64.b64encode(name.encode('utf-8')).decode('utf-8')
    pubsub_message = {
        'data': {'data': encoded_name}
    }

    process = subprocess.Popen(
      [
        'functions-framework',
        '--target', 'hello_pubsub',
        '--signature-type', 'event',
        '--port', str(port)
      ],
      cwd=os.path.dirname(__file__),
      stdout=subprocess.PIPE
    )

    # Send HTTP request simulating Pub/Sub message
    # (GCF translates Pub/Sub messages to HTTP requests internally)
    url = f'http://localhost:{port}/'

    retry_policy = Retry(total=6, backoff_factor=1)
    retry_adapter = requests.adapters.HTTPAdapter(
      max_retries=retry_policy)

    session = requests.Session()
    session.mount(url, retry_adapter)

    response = session.post(url, json=pubsub_message)

    assert response.status_code == 200

    # Stop the functions framework process
    process.kill()
    process.wait()
    out, err = process.communicate()

    print(out, err, response.content)

    assert f'Hello {name}!' in str(out)

Java


import static com.google.common.truth.Truth.assertThat;

import com.google.gson.Gson;
import io.github.resilience4j.core.IntervalFunction;
import io.github.resilience4j.retry.Retry;
import io.github.resilience4j.retry.RetryConfig;
import io.github.resilience4j.retry.RetryRegistry;
import io.vavr.CheckedRunnable;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.Map;
import java.util.UUID;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.HttpHostConnectException;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class ExampleIntegrationTest {
  // Root URL pointing to the locally hosted function
  // The Functions Framework Maven plugin lets us run a function locally
  private static final String BASE_URL = "http://localhost:8080";

  private static Process emulatorProcess = null;
  private static HttpClient client = HttpClientBuilder.create().build();
  private static final Gson gson = new Gson();

  @BeforeClass
  public static void setUp() throws IOException {
    // Get the sample's base directory (the one containing a pom.xml file)
    String baseDir = System.getProperty("basedir");

    // Emulate the function locally by running the Functions Framework Maven plugin
    emulatorProcess = new ProcessBuilder()
        .command("mvn", "function:run")
        .directory(new File(baseDir))
        .start();
  }

  @AfterClass
  public static void tearDown() {
    // Terminate the running Functions Framework Maven plugin process (if it's still running)
    if (emulatorProcess.isAlive()) {
      emulatorProcess.destroy();
    }
  }

  @Test
  public void helloPubSub_shouldRunWithFunctionsFramework() throws Throwable {
    String functionUrl = BASE_URL + "/helloPubsub"; // URL to your locally-running function

    // Initialize constants
    String name = UUID.randomUUID().toString();
    String nameBase64 = Base64.getEncoder().encodeToString(name.getBytes(StandardCharsets.UTF_8));

    String jsonStr = gson.toJson(Map.of("data", Map.of("data", nameBase64)));

    HttpPost postRequest =  new HttpPost(URI.create(functionUrl));
    postRequest.setEntity(new StringEntity(jsonStr));

    // The Functions Framework Maven plugin process takes time to start up
    // Use resilience4j to retry the test HTTP request until the plugin responds
    RetryRegistry registry = RetryRegistry.of(RetryConfig.custom()
        .maxAttempts(8)
        .retryExceptions(HttpHostConnectException.class)
        .intervalFunction(IntervalFunction.ofExponentialBackoff(200, 2))
        .build());
    Retry retry = registry.retry("my");

    // Perform the request-retry process
    CheckedRunnable retriableFunc = Retry.decorateCheckedRunnable(
        retry, () -> client.execute(postRequest));
    retriableFunc.run();

    // Get Functions Framework plugin process' stdout
    InputStream stdoutStream = emulatorProcess.getErrorStream();
    ByteArrayOutputStream stdoutBytes = new ByteArrayOutputStream();
    stdoutBytes.write(stdoutStream.readNBytes(stdoutStream.available()));

    // Verify desired name value is present
    assertThat(stdoutBytes.toString(StandardCharsets.UTF_8)).contains(
        String.format("Hello %s!", name));
  }
}

É possível executar os testes de integração para essa função da seguinte maneira:

Node.js

mocha test/sample.integration.pubsub.test.js --exit

Python

pytest sample_pubsub_test_integration.py

Java

mvn clean verify -Dtest=ExampleIntegrationTest

Testes do sistema

Estes são os testes do sistema para essa função:

Node.js

const childProcess = require('child_process');
const assert = require('assert');
const uuid = require('uuid');
const {PubSub} = require('@google-cloud/pubsub');
const moment = require('moment');
const promiseRetry = require('promise-retry');

const pubsub = new PubSub();
const topicName = process.env.FUNCTIONS_TOPIC;
const baseCmd = 'gcloud functions';

describe('system tests', () => {
  it('helloPubSub: should print a name', async () => {
    const name = uuid.v4();

    // Subtract time to work-around local-GCF clock difference
    const startTime = moment().subtract(4, 'minutes').toISOString();

    // Publish to pub/sub topic
    const topic = pubsub.topic(topicName);
    await topic.publish(Buffer.from(name));

    // Wait for logs to become consistent
    await promiseRetry((retry) => {
      const logs = childProcess
        .execSync(`${baseCmd} logs read helloPubSub --start-time ${startTime}`)
        .toString();

      try {
        assert.ok(logs.includes(`Hello, ${name}!`));
      } catch (err) {
        retry(err);
      }
    });
  });

Python

from datetime import datetime
from os import getenv
import subprocess
import time
import uuid

from google.cloud import pubsub_v1
import pytest

PROJECT = getenv('GCP_PROJECT')
TOPIC = getenv('TOPIC')

assert PROJECT is not None
assert TOPIC is not None

@pytest.fixture(scope='module')
def publisher_client():
    yield pubsub_v1.PublisherClient()

def test_print_name(publisher_client):
    start_time = datetime.utcnow().isoformat()
    topic_path = publisher_client.topic_path(PROJECT, TOPIC)

    # Publish the message
    name = uuid.uuid4()
    data = str(name).encode('utf-8')
    publisher_client.publish(topic_path, data=data).result()

    # Wait for logs to become consistent
    time.sleep(15)

    # Check logs after a delay
    log_process = subprocess.Popen([
        'gcloud',
        'alpha',
        'functions',
        'logs',
        'read',
        'hello_pubsub',
        '--start-time',
        start_time
    ], stdout=subprocess.PIPE)
    logs = str(log_process.communicate()[0])
    assert 'Hello {}!'.format(name) in logs

Go


package helloworld

import (
	"context"
	"log"
	"os"
	"os/exec"
	"strings"
	"testing"
	"time"

	"cloud.google.com/go/pubsub"
	"github.com/gobuffalo/uuid"
)

func TestHelloPubSubSystem(t *testing.T) {
	ctx := context.Background()

	topicName := os.Getenv("FUNCTIONS_TOPIC")
	projectID := os.Getenv("GCP_PROJECT")

	startTime := time.Now().UTC().Format(time.RFC3339)

	// Create the Pub/Sub client and topic.
	client, err := pubsub.NewClient(ctx, projectID)
	if err != nil {
		log.Fatal(err)
	}
	topic := client.Topic(topicName)

	// Publish a message with a random string to verify.
	// We use a random string to make sure the function is logging the correct
	// message for this test invocation.
	u := uuid.Must(uuid.NewV4())
	msg := &pubsub.Message{
		Data: []byte(u.String()),
	}
	topic.Publish(ctx, msg).Get(ctx)

	// Wait for logs to be consistent.
	time.Sleep(20 * time.Second)

	// Check logs after a delay.
	cmd := exec.Command("gcloud", "alpha", "functions", "logs", "read", "HelloPubSub", "--start-time", startTime)
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("exec.Command: %v", err)
	}
	if got := string(out); !strings.Contains(got, u.String()) {
		t.Errorf("HelloPubSub got %q, want to contain %q", got, u.String())
	}
}

Java

import static com.google.common.truth.Truth.assertThat;

import com.google.api.gax.paging.Page;
import com.google.cloud.logging.LogEntry;
import com.google.cloud.logging.Logging;
import com.google.cloud.logging.LoggingOptions;
import com.google.cloud.pubsub.v1.Publisher;
import com.google.protobuf.ByteString;
import com.google.pubsub.v1.ProjectTopicName;
import com.google.pubsub.v1.PubsubMessage;
import io.github.resilience4j.core.IntervalFunction;
import io.github.resilience4j.retry.Retry;
import io.github.resilience4j.retry.RetryConfig;
import io.github.resilience4j.retry.RetryRegistry;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.time.Instant;
import java.time.format.DateTimeFormatter;
import java.util.UUID;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import org.junit.BeforeClass;
import org.junit.Test;

public class ExampleSystemTest {

  // TODO<developer>: set these values (as environment variables)
  private static final String PROJECT_ID = System.getenv("GCP_PROJECT");
  private static final String TOPIC_NAME = System.getenv("FUNCTIONS_SYSTEM_TEST_TOPIC");
  private static final String FUNCTION_DEPLOYED_NAME = "HelloPubSub";

  private static Logging loggingClient;

  private static Publisher publisher;

  private HelloPubSub sampleUnderTest;

  @BeforeClass
  public static void setUp() throws IOException {
    loggingClient = LoggingOptions.getDefaultInstance().getService();
    publisher = Publisher.newBuilder(
        ProjectTopicName.of(PROJECT_ID, TOPIC_NAME)).build();
  }

  private static String getLogEntriesAsString(String startTimestamp) {
    // Construct Stackdriver logging filter
    // See this page for more info: https://cloud.google.com/logging/docs/view/advanced-queries
    String filter = "resource.type=\"cloud_function\""
        + " AND severity=INFO"
        + " AND resource.labels.function_name=" + FUNCTION_DEPLOYED_NAME
        + String.format(" AND timestamp>=\"%s\"", startTimestamp);

    // Get Stackdriver logging entries
    Page<LogEntry> logEntries =
        loggingClient.listLogEntries(
            Logging.EntryListOption.filter(filter),
            Logging.EntryListOption.sortOrder(
                Logging.SortingField.TIMESTAMP, Logging.SortingOrder.DESCENDING)
        );

    // Serialize Stackdriver logging entries + collect them into a single string
    String logsConcat = StreamSupport.stream(logEntries.getValues().spliterator(), false)
        .map((x) -> x.toString())
        .collect(Collectors.joining("%n"));

    return logsConcat;
  }

  @Test
  public void helloPubSub_shouldRunOnGcf() throws Exception {
    String name = UUID.randomUUID().toString();

    // Subtract time to work-around local-GCF clock difference
    Instant startInstant = Instant.now().minus(Duration.ofMinutes(4));
    String startTimestamp = DateTimeFormatter.ISO_INSTANT.format(startInstant);

    // Publish to pub/sub topic
    ByteString byteStr = ByteString.copyFrom(name, StandardCharsets.UTF_8);
    PubsubMessage pubsubApiMessage = PubsubMessage.newBuilder().setData(byteStr).build();
    publisher.publish(pubsubApiMessage).get();

    // Keep retrying until the logs contain the desired invocation's log entry
    // (If the invocation failed, the retry process will eventually time out)
    RetryRegistry registry = RetryRegistry.of(RetryConfig.custom()
        .maxAttempts(8)
        .intervalFunction(IntervalFunction.ofExponentialBackoff(1000, 2))
        .retryOnResult(s -> !s.toString().contains(name))
        .build());
    Retry retry = registry.retry(name);
    String logEntry = Retry
        .decorateFunction(retry, ExampleSystemTest::getLogEntriesAsString)
        .apply(startTimestamp);

    // Perform final assertion (to make sure we fail on timeout)
    assertThat(logEntry).contains(name);
  }
}

Faça os testes do sistema seguindo estas instruções:

  1. No projeto do Cloud, selecione um tópico do Pub/Sub para assinar. Se você digitar o nome de um tópico do Pub/Sub que não existe, ele será criado automaticamente.

  2. Em seguida, implante as funções usando este comando:

    Node.js

    gcloud functions deploy helloPubSub \
    --runtime nodejs10 \
    --trigger-topic YOUR_PUBSUB_TOPIC
    É possível usar os seguintes valores na sinalização --runtime para especificar a versão preferencial do Node.js:
    • nodejs10
    • nodejs12

    Python

    gcloud functions deploy hello_pubsub \
    --runtime python37 \
    --trigger-topic YOUR_PUBSUB_TOPIC
    É possível usar os seguintes valores da sinalização --runtime para especificar a versão preferencial do Python:
    • python37
    • python38

    Go

    gcloud functions deploy HelloPubSub \
    --runtime go111 \
    --trigger-topic YOUR_PUBSUB_TOPIC
    É possível usar os seguintes valores para a sinalização --runtime para especificar sua versão Go preferencial:
    • go111
    • go113

    Java

    gcloud functions deploy java-hello-pubsub \
    --entry-point functions.HelloPubSub \
    --runtime java11 \
    --memory 512MB \
    --trigger-topic YOUR_PUBSUB_TOPIC

    em que YOUR_PUBSUB_TOPIC é o nome do tópico do Pub/Sub de que suas funções devem ter uma assinatura.

  3. Faça os testes do sistema com este comando:

    Node.js

    export FUNCTIONS_TOPIC=YOUR_PUBSUB_TOPIC
    mocha test/sample.system.pubsub.test.js --exit
    

    Python

    export FUNCTIONS_TOPIC=YOUR_PUBSUB_TOPIC
    pytest sample_pubsub_test_system.py
    

    Go

    export FUNCTIONS_TOPIC=YOUR_PUBSUB_TOPIC
    go test -v ./hello_pubsub_system_test.go
    

    Java

    export FUNCTIONS_TOPIC=YOUR_PUBSUB_TOPIC
    mvn clean verify
    

    em que YOUR_PUBSUB_TOPIC é o nome do tópico do Pub/Sub de que suas funções devem ter uma assinatura.

Funções acionadas pelo armazenamento

Os testes de funções acionadas pelo armazenamento têm estrutura parecida com as equivalentes acionadas pelo Pub/Sub. Assim como os testes de funções acionados pelo Pub/Sub, os testes de funções acionados pelo armazenamento são estruturados de outra maneira dependendo de onde a função testada é hospedada.

Veja o exemplo de uma função acionada pelo armazenamento:

Node.js

/**
 * Generic background Cloud Function to be triggered by Cloud Storage.
 *
 * @param {object} file The Cloud Storage file metadata.
 * @param {object} context The event metadata.
 */
exports.helloGCS = (file, context) => {
  console.log(`  Event: ${context.eventId}`);
  console.log(`  Event Type: ${context.eventType}`);
  console.log(`  Bucket: ${file.bucket}`);
  console.log(`  File: ${file.name}`);
  console.log(`  Metageneration: ${file.metageneration}`);
  console.log(`  Created: ${file.timeCreated}`);
  console.log(`  Updated: ${file.updated}`);
};

Python

def hello_gcs(event, context):
    """Background Cloud Function to be triggered by Cloud Storage.
       This generic function logs relevant data when a file is changed.

    Args:
        event (dict):  The dictionary with data specific to this type of event.
                       The `data` field contains a description of the event in
                       the Cloud Storage `object` format described here:
                       https://cloud.google.com/storage/docs/json_api/v1/objects#resource
        context (google.cloud.functions.Context): Metadata of triggering event.
    Returns:
        None; the output is written to Stackdriver Logging
    """

    print('Event ID: {}'.format(context.event_id))
    print('Event type: {}'.format(context.event_type))
    print('Bucket: {}'.format(event['bucket']))
    print('File: {}'.format(event['name']))
    print('Metageneration: {}'.format(event['metageneration']))
    print('Created: {}'.format(event['timeCreated']))
    print('Updated: {}'.format(event['updated']))

Go


// Package helloworld provides a set of Cloud Functions samples.
package helloworld

import (
	"context"
	"fmt"
	"log"
	"time"

	"cloud.google.com/go/functions/metadata"
)

// GCSEvent is the payload of a GCS event.
type GCSEvent struct {
	Kind                    string                 `json:"kind"`
	ID                      string                 `json:"id"`
	SelfLink                string                 `json:"selfLink"`
	Name                    string                 `json:"name"`
	Bucket                  string                 `json:"bucket"`
	Generation              string                 `json:"generation"`
	Metageneration          string                 `json:"metageneration"`
	ContentType             string                 `json:"contentType"`
	TimeCreated             time.Time              `json:"timeCreated"`
	Updated                 time.Time              `json:"updated"`
	TemporaryHold           bool                   `json:"temporaryHold"`
	EventBasedHold          bool                   `json:"eventBasedHold"`
	RetentionExpirationTime time.Time              `json:"retentionExpirationTime"`
	StorageClass            string                 `json:"storageClass"`
	TimeStorageClassUpdated time.Time              `json:"timeStorageClassUpdated"`
	Size                    string                 `json:"size"`
	MD5Hash                 string                 `json:"md5Hash"`
	MediaLink               string                 `json:"mediaLink"`
	ContentEncoding         string                 `json:"contentEncoding"`
	ContentDisposition      string                 `json:"contentDisposition"`
	CacheControl            string                 `json:"cacheControl"`
	Metadata                map[string]interface{} `json:"metadata"`
	CRC32C                  string                 `json:"crc32c"`
	ComponentCount          int                    `json:"componentCount"`
	Etag                    string                 `json:"etag"`
	CustomerEncryption      struct {
		EncryptionAlgorithm string `json:"encryptionAlgorithm"`
		KeySha256           string `json:"keySha256"`
	}
	KMSKeyName    string `json:"kmsKeyName"`
	ResourceState string `json:"resourceState"`
}

// HelloGCS consumes a GCS event.
func HelloGCS(ctx context.Context, e GCSEvent) error {
	meta, err := metadata.FromContext(ctx)
	if err != nil {
		return fmt.Errorf("metadata.FromContext: %v", err)
	}
	log.Printf("Event ID: %v\n", meta.EventID)
	log.Printf("Event type: %v\n", meta.EventType)
	log.Printf("Bucket: %v\n", e.Bucket)
	log.Printf("File: %v\n", e.Name)
	log.Printf("Metageneration: %v\n", e.Metageneration)
	log.Printf("Created: %v\n", e.TimeCreated)
	log.Printf("Updated: %v\n", e.Updated)
	return nil
}

Java

import com.google.cloud.functions.BackgroundFunction;
import com.google.cloud.functions.Context;
import functions.eventpojos.GcsEvent;
import java.util.logging.Logger;

public class HelloGcs implements BackgroundFunction<GcsEvent> {
  private static final Logger logger = Logger.getLogger(HelloGcs.class.getName());

  @Override
  public void accept(GcsEvent event, Context context) {
    logger.info("Event: " + context.eventId());
    logger.info("Event Type: " + context.eventType());
    logger.info("Bucket: " + event.getBucket());
    logger.info("File: " + event.getName());
    logger.info("Metageneration: " + event.getMetageneration());
    logger.info("Created: " + event.getTimeCreated());
    logger.info("Updated: " + event.getUpdated());
  }
}

Testes de unidade

Veja os testes de unidade da função acima acionada pelo armazenamento:

Node.js

const assert = require('assert');
const uuid = require('uuid');
const sinon = require('sinon');

const {helloGCS} = require('..');

const stubConsole = function () {
  sinon.stub(console, `error`);
  sinon.stub(console, `log`);
};

const restoreConsole = function () {
  console.log.restore();
  console.error.restore();
};

beforeEach(stubConsole);
afterEach(restoreConsole);

it('helloGCS: should print out event', () => {
  // Initialize mocks
  const filename = uuid.v4();
  const eventType = 'google.storage.object.finalize';
  const event = {
    name: filename,
    resourceState: 'exists',
    metageneration: '1',
  };
  const context = {
    eventId: 'g1bb3r1sh',
    eventType: eventType
  }

  // Call tested function and verify its behavior
  helloGCS(event, context);
  assert.ok(console.log.calledWith(`  File: ${filename}`));
  assert.ok(console.log.calledWith(`  Event Type: ${eventType}`));
});

Python

import mock

import main

def test_print(capsys):
    name = 'test'
    event = {
        'bucket': 'some-bucket',
        'name': name,
        'metageneration': 'some-metageneration',
        'timeCreated': '0',
        'updated': '0'
    }

    context = mock.MagicMock()
    context.event_id = 'some-id'
    context.event_type = 'gcs-event'

    # Call tested function
    main.hello_gcs(event, context)
    out, err = capsys.readouterr()
    assert 'File: {}\n'.format(name) in out

Go

package helloworld

import (
	"context"
	"io/ioutil"
	"log"
	"os"
	"strings"
	"testing"

	"cloud.google.com/go/functions/metadata"
)

func TestHelloGCS(t *testing.T) {
	r, w, _ := os.Pipe()
	log.SetOutput(w)
	originalFlags := log.Flags()
	log.SetFlags(log.Flags() &^ (log.Ldate | log.Ltime))

	name := "hello_gcs.txt"
	e := GCSEvent{
		Name: name,
	}
	meta := &metadata.Metadata{
		EventID: "event ID",
	}
	ctx := metadata.NewContext(context.Background(), meta)

	HelloGCS(ctx, e)

	w.Close()
	log.SetOutput(os.Stderr)
	log.SetFlags(originalFlags)

	out, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("ReadAll: %v", err)
	}

	got := string(out)
	wants := []string{
		"File: " + name,
		"Event ID: " + meta.EventID,
	}
	for _, want := range wants {
		if !strings.Contains(got, want) {
			t.Errorf("HelloGCS(%v) = %q, want to contain %q", e, got, want)
		}
	}
}

Java

import static com.google.common.truth.Truth.assertThat;

import com.google.common.testing.TestLogHandler;
import functions.eventpojos.GcsEvent;
import functions.eventpojos.MockContext;
import java.util.logging.Logger;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

/**
 * Unit tests for main.java.com.example.functions.helloworld.HelloGcs.
 */
public class HelloGcsTest {
  private static final TestLogHandler LOG_HANDLER = new TestLogHandler();
  private static final Logger logger = Logger.getLogger(HelloGcs.class.getName());

  @Before
  public void beforeTest() throws Exception {
    logger.addHandler(LOG_HANDLER);
  }

  @After
  public void afterTest() {
    LOG_HANDLER.clear();
  }

  @Test
  public void helloGcs_shouldPrintFileName() {
    GcsEvent event = new GcsEvent();
    event.setName("foo.txt");

    MockContext context = new MockContext();
    context.eventType = "google.storage.object.finalize";

    new HelloGcs().accept(event, context);

    String message = LOG_HANDLER.getStoredLogRecords().get(3).getMessage();
    assertThat(message).contains("File: foo.txt");
  }
}

Faça os testes de unidade com este comando:

Node.js

mocha test/sample.unit.storage.test.js --exit

Python

pytest sample_storage_test.py

Go

go test -v ./hello_cloud_storage_test.go

Java

mvn clean verify

Testes de integração

Veja os testes de integração da função acima acionada pelo armazenamento:

Node.js

const assert = require('assert');
const execPromise = require('child-process-promise').exec;
const path = require('path');
const uuid = require('uuid');

const requestRetry = require('requestretry');
const cwd = path.join(__dirname, '..');

  it('helloGCSGeneric: should print GCS event', async () => {
    const filename = uuid.v4(); // Use a unique filename to avoid conflicts
    const PORT = 9000; // Each running framework instance needs a unique port

    const eventType = 'google.storage.object.finalize';

    const data = {
      data: {
        name: filename,
        resourceState: 'exists',
        metageneration: '1',
      },
      context: {
        eventType: eventType
      }
    };

    // Run the functions-framework instance to host functions locally
    //   exec's 'timeout' param won't kill children of "shim" /bin/sh process
    //   Workaround: include "& sleep <TIMEOUT>; kill $!" in executed command
    const proc = execPromise(
      `functions-framework --target=helloGCS --signature-type=event --port=${PORT} & sleep 1; kill $!`,
      {shell: true, cwd}
    );

    // Send HTTP request simulating GCS change notification
    // (GCF translates GCS notifications to HTTP requests internally)
    const response = await requestRetry({
      url: `http://localhost:${PORT}/`,
      method: 'POST',
      body: data,
      retryDelay: 200,
      json: true,
    });

    assert.strictEqual(response.statusCode, 204);

    // Wait for functions-framework process to exit
    const {stdout} = await proc;
    assert.ok(stdout.includes(`File: ${filename}`));
    assert.ok(stdout.includes(`Event Type: ${eventType}`));
  });
});

Java


import static com.google.common.truth.Truth.assertThat;

import com.google.gson.Gson;
import io.github.resilience4j.core.IntervalFunction;
import io.github.resilience4j.retry.Retry;
import io.github.resilience4j.retry.RetryConfig;
import io.github.resilience4j.retry.RetryRegistry;
import io.vavr.CheckedRunnable;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.Map;
import java.util.UUID;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.HttpHostConnectException;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class ExampleIntegrationTest {
  // Root URL pointing to the locally hosted function
  // The Functions Framework Maven plugin lets us run a function locally
  private static final String BASE_URL = "http://localhost:8080";

  private static Process emulatorProcess = null;
  private static final HttpClient client = HttpClientBuilder.create().build();
  private static final Gson gson = new Gson();

  @BeforeClass
  public static void setUp() throws IOException {
    // Get the sample's base directory (the one containing a pom.xml file)
    String baseDir = System.getProperty("basedir");

    // Emulate the function locally by running the Functions Framework Maven plugin
    emulatorProcess = new ProcessBuilder()
        .command("mvn", "function:run")
        .directory(new File(baseDir))
        .start();
  }

  @AfterClass
  public static void tearDown() {
    // Terminate the running Functions Framework Maven plugin process (if it's still running)
    if (emulatorProcess.isAlive()) {
      emulatorProcess.destroy();
    }
  }

  @Test
  public void helloGcs_shouldRunWithFunctionsFramework() throws Throwable {
    String functionUrl = BASE_URL + "/helloGcs"; // URL to your locally-running function

    // Initialize constants
    String name = UUID.randomUUID().toString();
    String jsonStr = gson.toJson(Map.of(
        "data", Map.of(
            "name", name, "resourceState", "exists", "metageneration", 1),
        "context", Map.of(
            "eventType", "google.storage.object.finalize")
    ));

    HttpPost postRequest =  new HttpPost(URI.create(functionUrl));
    postRequest.setEntity(new StringEntity(jsonStr));

    // The Functions Framework Maven plugin process takes time to start up
    // Use resilience4j to retry the test HTTP request until the plugin responds
    RetryRegistry registry = RetryRegistry.of(RetryConfig.custom()
        .maxAttempts(8)
        .retryExceptions(HttpHostConnectException.class)
        .intervalFunction(IntervalFunction.ofExponentialBackoff(200, 2))
        .build());
    Retry retry = registry.retry("my");

    // Perform the request-retry process
    CheckedRunnable retriableFunc = Retry.decorateCheckedRunnable(
        retry, () -> client.execute(postRequest));
    retriableFunc.run();

    // Get Functions Framework plugin process' stdout
    InputStream stdoutStream = emulatorProcess.getErrorStream();
    ByteArrayOutputStream stdoutBytes = new ByteArrayOutputStream();
    stdoutBytes.write(stdoutStream.readNBytes(stdoutStream.available()));

    // Verify desired name value is present
    assertThat(stdoutBytes.toString(StandardCharsets.UTF_8)).contains(
        String.format("File: %s", name));
  }
}

É possível executar os testes de integração para essa função da seguinte maneira:

Node.js

mocha test/sample.integration.storage.test.js --exit

Java

mvn clean verify -Dtest=ExampleIntegrationTest

Testes do sistema

Estes são os testes de sistema para a função acionada pelo armazenamento acima:

Node.js

const {Storage} = require('@google-cloud/storage');
const storage = new Storage();
const uuid = require('uuid');
const assert = require('assert');
const path = require('path');
const childProcess = require('child_process');
const moment = require('moment');
const promiseRetry = require('promise-retry');

// Use unique GCS filename to avoid conflicts between concurrent test runs
const gcsFileName = `test-${uuid.v4()}.txt`;

const localFileName = 'test.txt';
const bucketName = process.env.FUNCTIONS_DELETABLE_BUCKET;
const bucket = storage.bucket(bucketName);
const baseCmd = 'gcloud functions';

describe('system tests', () => {
  it('helloGCS: should print event', async () => {
    // Subtract time to work-around local-GCF clock difference
    const startTime = moment().subtract(2, 'minutes').toISOString();

    // Upload file
    const filepath = path.join(__dirname, localFileName);
    await bucket.upload(filepath, {
      destination: gcsFileName,
    });

    // Wait for logs to become consistent
    await promiseRetry((retry) => {
      const logs = childProcess
        .execSync(`${baseCmd} logs read helloGCS --start-time ${startTime}`)
        .toString();

      try {
        assert.ok(logs.includes(`Filename: ${gcsFileName}`));
        assert.ok(logs.includes(`Event Type: google.storage.object.finalize`));
      } catch (err) {
        retry(err);
      }
    });
  });

Python

from datetime import datetime
from os import getenv, path
import subprocess
import time
import uuid

from google.cloud import storage
import pytest

PROJECT = getenv('GCP_PROJECT')
BUCKET = getenv('BUCKET')

assert PROJECT is not None
assert BUCKET is not None

@pytest.fixture(scope='module')
def storage_client():
    yield storage.Client()

@pytest.fixture(scope='module')
def bucket_object(storage_client):
    bucket_object = storage_client.get_bucket(BUCKET)
    yield bucket_object

@pytest.fixture(scope='module')
def uploaded_file(bucket_object):
    name = 'test-{}.txt'.format(str(uuid.uuid4()))
    blob = bucket_object.blob(name)

    test_dir = path.dirname(path.abspath(__file__))
    blob.upload_from_filename(path.join(test_dir, 'test.txt'))
    yield name
    blob.delete()

def test_hello_gcs(uploaded_file):
    start_time = datetime.utcnow().isoformat()
    time.sleep(10)  # Wait for logs to become consistent

    log_process = subprocess.Popen([
        'gcloud',
        'alpha',
        'functions',
        'logs',
        'read',
        'hello_gcs_generic',
        '--start-time',
        start_time
    ], stdout=subprocess.PIPE)
    logs = str(log_process.communicate()[0])
    assert uploaded_file in logs

Go


package helloworld

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"strings"
	"testing"
	"time"

	"cloud.google.com/go/storage"
)

func TestHelloGCSSystem(t *testing.T) {
	ctx := context.Background()
	bucketName := os.Getenv("BUCKET_NAME")

	client, err := storage.NewClient(ctx)
	if err != nil {
		t.Fatalf("storage.NewClient: %v", err)
	}

	// Create a file.
	startTime := time.Now().UTC().Format(time.RFC3339)
	oh := client.Bucket(bucketName).Object("TestHelloGCSSystem")
	w := oh.NewWriter(ctx)
	fmt.Fprintf(w, "Content of the file")
	w.Close()

	// Wait for logs to be consistent.
	time.Sleep(20 * time.Second)

	// Check logs.
	want := "created"
	if got := readLogs(t, startTime); !strings.Contains(got, want) {
		t.Errorf("HelloGCS logged %q, want to contain %q", got, want)
	}

	// Modify the file.
	startTime = time.Now().UTC().Format(time.RFC3339)
	_, err = oh.Update(ctx, storage.ObjectAttrsToUpdate{
		Metadata: map[string]string{"Content-Type": "text/html"},
	})
	if err != nil {
		t.Errorf("Update: %v", err)
	}

	// Wait for logs to be consistent.
	time.Sleep(20 * time.Second)

	// Check logs.
	want = "updated"
	if got := readLogs(t, startTime); !strings.Contains(got, want) {
		t.Errorf("HelloGCS logged %q, want to contain %q", got, want)
	}

	// Delete the file.
	startTime = time.Now().UTC().Format(time.RFC3339)
	if err := oh.Delete(ctx); err != nil {
		t.Errorf("Delete: %v", err)
	}

	// Wait for logs to be consistent.
	time.Sleep(20 * time.Second)

	// Check logs.
	want = "deleted"
	if got := readLogs(t, startTime); !strings.Contains(got, want) {
		t.Errorf("HelloGCS logged %q, want to contain %q", got, want)
	}
}

func readLogs(t *testing.T, startTime string) string {
	t.Helper()
	cmd := exec.Command("gcloud", "alpha", "functions", "logs", "read", "HelloGCS", "--start-time", startTime)
	got, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("exec.Command: %v", err)
	}
	return string(got)
}

Java

import static com.google.common.truth.Truth.assertThat;

import com.google.api.gax.paging.Page;
import com.google.cloud.logging.LogEntry;
import com.google.cloud.logging.Logging;
import com.google.cloud.logging.LoggingOptions;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import io.github.resilience4j.core.IntervalFunction;
import io.github.resilience4j.retry.Retry;
import io.github.resilience4j.retry.RetryConfig;
import io.github.resilience4j.retry.RetryRegistry;
import java.io.IOException;
import java.time.Duration;
import java.time.Instant;
import java.time.format.DateTimeFormatter;
import java.util.UUID;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import org.junit.BeforeClass;
import org.junit.Test;

public class ExampleSystemTest {

  // TODO<developer>: set these values (as environment variables)
  private static final String PROJECT_ID = System.getenv("GCP_PROJECT");
  private static final String FUNCTIONS_BUCKET = System.getenv("FUNCTIONS_BUCKET");
  private static final String FUNCTION_DEPLOYED_NAME = "HelloGcs";
  private static final Storage STORAGE = StorageOptions.getDefaultInstance().getService();

  private static Logging loggingClient;

  private HelloGcs sampleUnderTest;

  @BeforeClass
  public static void setUp() throws IOException {
    loggingClient = LoggingOptions.getDefaultInstance().getService();
  }

  private static String getLogEntriesAsString(String startTimestamp) {
    // Construct Stackdriver logging filter
    // See this page for more info: https://cloud.google.com/logging/docs/view/advanced-queries
    String filter = "resource.type=\"cloud_function\""
        + " AND severity=INFO"
        + " AND resource.labels.function_name=" + FUNCTION_DEPLOYED_NAME
        + String.format(" AND timestamp>=\"%s\"", startTimestamp);

    // Get Stackdriver logging entries
    Page<LogEntry> logEntries =
        loggingClient.listLogEntries(
            Logging.EntryListOption.filter(filter),
            Logging.EntryListOption.sortOrder(
                Logging.SortingField.TIMESTAMP, Logging.SortingOrder.DESCENDING)
        );

    // Serialize Stackdriver logging entries + collect them into a single string
    String logsConcat = StreamSupport.stream(logEntries.getValues().spliterator(), false)
        .map((x) -> x.toString())
        .collect(Collectors.joining("%n"));

    return logsConcat;
  }

  @Test
  public void helloGcs_shouldRunOnGcf() {
    String filename = String.format("test-%s.txt", UUID.randomUUID());

    // Subtract time to work-around local-GCF clock difference
    Instant startInstant = Instant.now().minus(Duration.ofMinutes(4));
    String startTimestamp = DateTimeFormatter.ISO_INSTANT.format(startInstant);

    // Upload a file to Cloud Storage
    BlobInfo blobInfo = BlobInfo.newBuilder(BlobId.of(FUNCTIONS_BUCKET, filename)).build();
    STORAGE.create(blobInfo);

    // Keep retrying until the logs contain the desired invocation's log entry
    // (If the invocation failed, the retry process will eventually time out)
    String expected = String.format("File: %s", filename);
    RetryRegistry registry = RetryRegistry.of(RetryConfig.custom()
        .maxAttempts(8)
        .intervalFunction(IntervalFunction.ofExponentialBackoff(1000, 2))
        .retryOnResult(s -> !s.toString().contains(expected))
        .build());
    Retry retry = registry.retry(filename);
    String logEntry = Retry
        .decorateFunction(retry, ExampleSystemTest::getLogEntriesAsString)
        .apply(startTimestamp);

    // Perform final assertion (to make sure we fail on timeout)
    assertThat(logEntry).contains(filename);
  }
}

Implante a função com este comando:

Node.js

gcloud functions deploy helloGCS \
--runtime nodejs10 \
--trigger-bucket YOUR_GCS_BUCKET_NAME
É possível usar os seguintes valores na sinalização --runtime para especificar a versão preferencial do Node.js:
  • nodejs10
  • nodejs12

Python

gcloud functions deploy hello_gcs \
--runtime python37 \
--trigger-bucket YOUR_GCS_BUCKET_NAME
É possível usar os seguintes valores da sinalização --runtime para especificar a versão preferencial do Python:
  • python37
  • python38

Go

gcloud functions deploy HelloGCS \
--runtime go111 \
--trigger-bucket YOUR_GCS_BUCKET_NAME
É possível usar os seguintes valores para a sinalização --runtime para especificar sua versão Go preferencial:
  • go111
  • go113

Java

gcloud functions deploy java-hello-gcs \
--entry-point functions.HelloGcs \
--runtime java11 \
--memory 512MB \
--trigger-bucket YOUR_GCS_BUCKET_NAME

em que YOUR_GCS_BUCKET_NAME é o bucket do Cloud Storage que você deve monitorar. É necessário que faça referência a um bucket que exista no mesmo projeto do Cloud em que a função está implantada.

Faça testes do sistema com estes comandos:

Node.js

export BUCKET_NAME=YOUR_GCS_BUCKET_NAME
mocha test/sample.system.storage.test.js --exit

Python

export BUCKET_NAME=YOUR_GCS_BUCKET_NAME
pytest sample_storage_test_system.py

Go

export BUCKET_NAME=YOUR_GCS_BUCKET_NAME
go test -v ./hello_cloud_storage_system_test.go

Java

mvn clean verify