Pengendali Pub/Sub untuk memproses peristiwa Cloud Storage

Tutorial ini menunjukkan penggunaan Cloud Run, Cloud Vision API, dan ImageMagick untuk mendeteksi dan memburamkan gambar menyinggung yang diupload ke bucket Cloud Storage.

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Untuk dokumentasi mendetail yang menyertakan contoh kode ini, lihat artikel berikut:

Contoh kode

GoJavaNode.jsPython

Untuk melakukan autentikasi ke Cloud Run, siapkan Kredensial Default Aplikasi. Untuk mengetahui informasi selengkapnya, lihat Menyiapkan autentikasi untuk lingkungan pengembangan lokal. 


// Sample image-processing is a Cloud Run service which performs asynchronous processing on images.
package main

import (
	"encoding/json"
	"io"
	"log"
	"net/http"
	"os"

	"github.com/GoogleCloudPlatform/golang-samples/run/image-processing/imagemagick"
)

func main() {
	http.HandleFunc("/", HelloPubSub)
	// Determine port for HTTP service.
	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}
	// Start HTTP server.
	log.Printf("Listening on port %s", port)
	if err := http.ListenAndServe(":"+port, nil); err != nil {
		log.Fatal(err)
	}
}

// PubSubMessage is the payload of a Pub/Sub event.
// See the documentation for more details:
// https://cloud.google.com/pubsub/docs/reference/rest/v1/PubsubMessage
type PubSubMessage struct {
	Message struct {
		Data []byte `json:"data,omitempty"`
		ID   string `json:"id"`
	} `json:"message"`
	Subscription string `json:"subscription"`
}

// HelloPubSub receives and processes a Pub/Sub push message.
func HelloPubSub(w http.ResponseWriter, r *http.Request) {
	var m PubSubMessage
	body, err := io.ReadAll(r.Body)
	if err != nil {
		log.Printf("ioutil.ReadAll: %v", err)
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}
	if err := json.Unmarshal(body, &m); err != nil {
		log.Printf("json.Unmarshal: %v", err)
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}

	var e imagemagick.GCSEvent
	if err := json.Unmarshal(m.Message.Data, &e); err != nil {
		log.Printf("json.Unmarshal: %v", err)
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}

	if e.Name == "" || e.Bucket == "" {
		log.Printf("invalid GCSEvent: expected name and bucket")
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}

	if err := imagemagick.BlurOffensiveImages(r.Context(), e); err != nil {
		log.Printf("imagemagick.BlurOffensiveImages: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

Untuk melakukan autentikasi ke Cloud Run, siapkan Kredensial Default Aplikasi. Untuk mengetahui informasi selengkapnya, lihat Menyiapkan autentikasi untuk lingkungan pengembangan lokal. 

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import java.util.Base64;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

// PubsubController consumes a Pub/Sub message.
@RestController
public class PubSubController {
  @RequestMapping(value = "/", method = RequestMethod.POST)
  public ResponseEntity<String> receiveMessage(@RequestBody Body body) {
    // Get PubSub message from request body.
    Body.Message message = body.getMessage();
    if (message == null) {
      String msg = "Bad Request: invalid Pub/Sub message format";
      System.out.println(msg);
      return new ResponseEntity<>(msg, HttpStatus.BAD_REQUEST);
    }

    // Decode the Pub/Sub message.
    String pubSubMessage = message.getData();
    JsonObject data;
    try {
      String decodedMessage = new String(Base64.getDecoder().decode(pubSubMessage));
      data = JsonParser.parseString(decodedMessage).getAsJsonObject();
    } catch (Exception e) {
      String msg = "Error: Invalid Pub/Sub message: data property is not valid base64 encoded JSON";
      System.out.println(msg);
      return new ResponseEntity<>(msg, HttpStatus.BAD_REQUEST);
    }

    // Validate the message is a Cloud Storage event.
    if (data.get("name") == null || data.get("bucket") == null) {
      String msg = "Error: Invalid Cloud Storage notification: expected name and bucket properties";
      System.out.println(msg);
      return new ResponseEntity<>(msg, HttpStatus.BAD_REQUEST);
    }

    try {
      ImageMagick.blurOffensiveImages(data);
    } catch (Exception e) {
      String msg = String.format("Error: Blurring image: %s", e.getMessage());
      System.out.println(msg);
      return new ResponseEntity<>(msg, HttpStatus.INTERNAL_SERVER_ERROR);
    }
    return new ResponseEntity<>(HttpStatus.OK);
  }
}

Untuk melakukan autentikasi ke Cloud Run, siapkan Kredensial Default Aplikasi. Untuk mengetahui informasi selengkapnya, lihat Menyiapkan autentikasi untuk lingkungan pengembangan lokal. 


const express = require('express');
const app = express();

// This middleware is available in Express v4.16.0 onwards
app.use(express.json());

const image = require('./image');

app.post('/', async (req, res) => {
  if (!req.body) {
    const msg = 'no Pub/Sub message received';
    console.error(`error: ${msg}`);
    res.status(400).send(`Bad Request: ${msg}`);
    return;
  }
  if (!req.body.message || !req.body.message.data) {
    const msg = 'invalid Pub/Sub message format';
    console.error(`error: ${msg}`);
    res.status(400).send(`Bad Request: ${msg}`);
    return;
  }

  // Decode the Pub/Sub message.
  const pubSubMessage = req.body.message;
  let data;
  try {
    data = Buffer.from(pubSubMessage.data, 'base64').toString().trim();
    data = JSON.parse(data);
  } catch (err) {
    const msg =
      'Invalid Pub/Sub message: data property is not valid base64 encoded JSON';
    console.error(`error: ${msg}: ${err}`);
    res.status(400).send(`Bad Request: ${msg}`);
    return;
  }

  // Validate the message is a Cloud Storage event.
  if (!data.name || !data.bucket) {
    const msg =
      'invalid Cloud Storage notification: expected name and bucket properties';
    console.error(`error: ${msg}`);
    res.status(400).send(`Bad Request: ${msg}`);
    return;
  }

  try {
    await image.blurOffensiveImages(data);
    res.status(204).send();
  } catch (err) {
    console.error(`error: Blurring image: ${err}`);
    res.status(500).send();
  }
});

Untuk melakukan autentikasi ke Cloud Run, siapkan Kredensial Default Aplikasi. Untuk mengetahui informasi selengkapnya, lihat Menyiapkan autentikasi untuk lingkungan pengembangan lokal. 

import base64
import json
import os

from flask import Flask, request

import image


app = Flask(__name__)


@app.route("/", methods=["POST"])
def index():
    """Receive and parse Pub/Sub messages containing Cloud Storage event data."""
    envelope = request.get_json()
    if not envelope:
        msg = "no Pub/Sub message received"
        print(f"error: {msg}")
        return f"Bad Request: {msg}", 400

    if not isinstance(envelope, dict) or "message" not in envelope:
        msg = "invalid Pub/Sub message format"
        print(f"error: {msg}")
        return f"Bad Request: {msg}", 400

    # Decode the Pub/Sub message.
    pubsub_message = envelope["message"]

    if isinstance(pubsub_message, dict) and "data" in pubsub_message:
        try:
            data = json.loads(base64.b64decode(pubsub_message["data"]).decode())

        except Exception as e:
            msg = (
                "Invalid Pub/Sub message: "
                "data property is not valid base64 encoded JSON"
            )
            print(f"error: {e}")
            return f"Bad Request: {msg}", 400

        # Validate the message is a Cloud Storage event.
        if not data["name"] or not data["bucket"]:
            msg = (
                "Invalid Cloud Storage notification: "
                "expected name and bucket properties"
            )
            print(f"error: {msg}")
            return f"Bad Request: {msg}", 400

        try:
            image.blur_offensive_images(data)
            return ("", 204)

        except Exception as e:
            print(f"error: {e}")
            return ("", 500)

    return ("", 500)

Langkah berikutnya

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