upload /download to firebase google and to AWS S3 golang

go_upload_to_cloud.go

//---------- Firestore -------------

// ********* UPLOAD *******
configStorage := &firebase.Config{
		StorageBucket: "xxxxxxxxxxxxxxxxx.appspot.com",
	}
	opt := option.WithCredentialsFile("./config/serviceAccountKey.json")
	app, err := firebase.NewApp(context.Background(), configStorage, opt)
	if err != nil {
		log.Error(err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	client, err := app.Storage(context.Background())
	if err != nil {
		log.Error(err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	bucket, err := client.DefaultBucket()
	if err != nil {
		log.Error(err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	docName := user.ID + "/" + user.ID + "_" + newID + filepath.Ext(header.Filename)

	// upload it to google cloud store
	go func() {
		wc := bucket.Object(docName).NewWriter(context.Background())
		if _, err = io.Copy(wc, uploadedFile); err != nil {
			log.Error(err)
			return
		}
		err = wc.Close()
		if err != nil {
			log.Error(err)
		}
	}()
  
  
//******* DOWNLOAD ********
// downloads a file from cloud
func downloadFromCloudStorage(fileURI string) ([]byte, error) {

	configStorage := &firebase.Config{
		StorageBucket: "fxxxxxxxxxxx.appspot.com",
	}
	opt := option.WithCredentialsFile("./config/serviceAccountKey.json")
	app, err := firebase.NewApp(context.Background(), configStorage, opt)
	if err != nil {
		return nil, err
	}

	client, err := app.Storage(context.Background())
	if err != nil {
		return nil, err
	}

	bucket, err := client.DefaultBucket()
	if err != nil {
		return nil, err
	}

	rc, err := bucket.Object(fileURI).NewReader(context.Background())
	if err != nil {
		return nil, err
	}
	defer rc.Close()

	data, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, err
	}
	return data, nil

}

  //--------- S3 -----------
  sess, err := session.NewSession(&aws.Config{Region: aws.String("ca-central-1"),
		S3ForcePathStyle: aws.Bool(true), LogLevel: aws.LogLevel(aws.LogDebugWithRequestErrors),
		Credentials: credentials.NewStaticCredentials("XXXXXXXXX", "YYYYYYYYYYYYYYYYYYYYYY/", "")})
	if err != nil {
		panic(err)
	}

	s3client := s3.New(sess)

	file, err := os.Open("testfile.jpg")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer file.Close()

	fileInfo, _ := file.Stat()
	var size = fileInfo.Size()

	buffer := make([]byte, size)

	// read file content to buffer
	file.Read(buffer)

	fileBytes := bytes.NewReader(buffer) // convert to io.ReadSeeker type

	fileType := http.DetectContentType(buffer)

	path := file.Name() // you can add folder by "/examplefolder/"

	params := &s3.PutObjectInput{
		Bucket:        aws.String(bucketName), // required
		Key:           aws.String(path),       // required
		ACL:           aws.String("public-read"),
		Body:          fileBytes,
		ContentLength: aws.Int64(size),
		ContentType:   aws.String(fileType),
		Metadata: map[string]*string{
			"Key": aws.String("MetadataValue"), //required
		},
		// see more at http://godoc.org/github.com/aws/aws-sdk-go/service/s3#S3.PutObject
	}

	result, err := s3client.PutObject(params)
	if err != nil {
		if awsErr, ok := err.(awserr.Error); ok {
			// Generic AWS Error with Code, Message, and original error (if any)
			fmt.Println(awsErr.Code(), awsErr.Message(), awsErr.OrigErr())
			if reqErr, ok := err.(awserr.RequestFailure); ok {
				// A service error occurred
				fmt.Println(reqErr.Code(), reqErr.Message(), reqErr.StatusCode(), reqErr.RequestID())
			}
		} else {
			// This case should never be hit, the SDK should always return an
			// error which satisfies the awserr.Error interface.
			fmt.Println(err.Error())
		}
	}

	fmt.Println(awsutil.StringValue(result))