Golang storage.NewClient函數代碼示例

func (s *shard) createOutputFile(c context.Context) (io.WriteCloser, error) {
	c, _ = context.WithTimeout(c, time.Duration(10)*time.Minute)
	// for development we can't use the appengine default credentials so
	// instead need to create our own oauth token source to access storage

	// TODO: maybe give job a chance to generate this - it could also
	// create the writer (?). The only reason we're doing it is to prevent
	// duplication and also handle the file rollup operations
	var client *cstorage.Client
	if appengine.IsDevAppServer() {
		jsonKey, err := ioutil.ReadFile("service-account.json")
		if err != nil {
			return nil, err
		}
		conf, err := google.JWTConfigFromJSON(jsonKey, cstorage.ScopeReadWrite)
		if err != nil {
			return nil, err
		}
		client, err = cstorage.NewClient(c, option.WithTokenSource(conf.TokenSource(c)))
		if err != nil {
			return nil, err
		}
	} else {
		var err error
		client, err = cstorage.NewClient(c)
		if err != nil {
			return nil, err
		}
	}

	o := client.Bucket(s.job.Bucket).Object(s.sliceFilename(s.Sequence)).NewWriter(c)

	// TODO: wrap writer to count bytes and continue slice if we get close to 10Mb limit (?)
	return o, nil
}

func main() {
	log.SetPrefix("gcsbench: ")
	log.SetFlags(0)

	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "usage: gcsbench -b bucketName\n")
		os.Exit(2)
	}
	flag.Parse()
	if *bucketName == "" || len(flag.Args()) > 0 {
		flag.Usage()
	}

	http.DefaultTransport = newLogger(http.DefaultTransport)

	start := time.Now()
	var (
		mu    sync.Mutex
		total time.Duration
	)
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		log.Fatalf("storage.NewClient: %v", err)
	}
	sema := make(chan bool, *parallel)
	for i := 0; i < *count; i++ {
		sema <- true
		name := fmt.Sprintf("gcsbench/tmp.%d", i)
		go func() {
			start := time.Now()
			client := client
			if *newClient {
				var err error
				client, err = storage.NewClient(ctx)
				if err != nil {
					log.Fatalf("storage.NewClient: %v", err)
				}
			}
			obj := client.Bucket(*bucketName).Object(name)
			w := obj.NewWriter(ctx)
			w.Write(make([]byte, *size))
			if err := w.Close(); err != nil {
				log.Fatalf("writing file: %v", err)
			}
			mu.Lock()
			total += time.Since(start)
			mu.Unlock()
			<-sema
		}()
	}
	for i := 0; i < *parallel; i++ {
		sema <- true
	}

	fmt.Printf("avg %.3fs per write\n", (total / time.Duration(*count)).Seconds())
	elapsed := time.Since(start)
	fmt.Printf("total %.3fs %.3f MB/s\n", elapsed.Seconds(), float64(*count)*float64(*size)/1e6/elapsed.Seconds())
}

func Setup(t *testing.T) *storage.Client {
	if testProject == "" || testBucket == "" {
		t.Skip("TESTPROJECT, and TESTBUCKET EnvVars must be set to perform integration test")
	}

	gcsctx := &cloudstorage.CloudStoreContext{
		LogggingContext: "testing-config",
		TokenSource:     cloudstorage.GCEDefaultOAuthToken,
		Project:         testProject,
		Bucket:          testBucket,
	}

	// Create http client with Google context auth
	googleClient, err := cloudstorage.NewGoogleClient(gcsctx)
	if err != nil {
		t.Errorf("Failed to create Google Client: %v\n", err)
	}

	gsc, err := storage.NewClient(context.Background(), option.WithHTTPClient(googleClient.Client()))
	if err != nil {
		t.Errorf("Error creating Google cloud storage client. project:%s gs://%s/ err:%v\n",
			gcsctx.Project, gcsctx.Bucket, err)

	}
	if gsc == nil {
		t.Errorf("storage Client returned is nil!")
	}
	return gsc
}

func ExampleObjectHandle_Delete() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	// To delete multiple objects in a bucket, list them with an
	// ObjectIterator, then Delete them.

	// If you are using this package on the App Engine Flex runtime,
	// you can init a bucket client with your app's default bucket name.
	// See http://godoc.org/google.golang.org/appengine/file#DefaultBucketName.
	bucket := client.Bucket("my-bucket")
	it := bucket.Objects(ctx, nil)
	for {
		objAttrs, err := it.Next()
		if err != nil && err != storage.Done {
			// TODO: Handle error.
		}
		if err == storage.Done {
			break
		}
		if err := bucket.Object(objAttrs.Name).Delete(ctx); err != nil {
			// TODO: Handle error.
		}
	}
	fmt.Println("deleted all object items in the bucket specified.")
}

func ExampleComposer_Run() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	bkt := client.Bucket("bucketname")
	src1 := bkt.Object("o1")
	src2 := bkt.Object("o2")
	dst := bkt.Object("o3")
	// Compose and modify metadata.
	c := dst.ComposerFrom(src1, src2)
	c.ContentType = "text/plain"
	attrs, err := c.Run(ctx)
	if err != nil {
		// TODO: Handle error.
	}
	fmt.Println(attrs)
	// Just compose.
	attrs, err = dst.ComposerFrom(src1, src2).Run(ctx)
	if err != nil {
		// TODO: Handle error.
	}
	fmt.Println(attrs)
}

func ExampleCopier_Run() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	src := client.Bucket("bucketname").Object("file1")
	dst := client.Bucket("another-bucketname").Object("file2")

	// Copy content and modify metadata.
	copier := dst.CopierFrom(src)
	copier.ContentType = "text/plain"
	attrs, err := copier.Run(ctx)
	if err != nil {
		// TODO: Handle error, possibly resuming with copier.RewriteToken.
	}
	fmt.Println(attrs)

	// Just copy content.
	attrs, err = dst.CopierFrom(src).Run(ctx)
	if err != nil {
		// TODO: Handle error. No way to resume.
	}
	fmt.Println(attrs)
}

// getInstalledTLS returns the TLS certificate and key stored on Google Cloud Storage for the
// instance defined in d.Conf.
//
// If either the TLS keypair doesn't exist, the error is os.ErrNotExist.
func (d *Deployer) getInstalledTLS() (certPEM, keyPEM []byte, err error) {
	ctx := context.Background()
	stoClient, err := cloudstorage.NewClient(ctx, option.WithHTTPClient(d.Client))
	if err != nil {
		return nil, nil, fmt.Errorf("error creating Cloud Storage client to fetch TLS cert & key from new instance: %v", err)
	}
	getFile := func(name string) ([]byte, error) {
		sr, err := stoClient.Bucket(d.Conf.bucketBase()).Object(path.Join(configDir, name)).NewReader(ctx)
		if err == cloudstorage.ErrObjectNotExist {
			return nil, os.ErrNotExist
		}
		if err != nil {
			return nil, err
		}
		defer sr.Close()
		return ioutil.ReadAll(sr)
	}
	var grp syncutil.Group
	grp.Go(func() (err error) {
		certPEM, err = getFile(certFilename())
		return
	})
	grp.Go(func() (err error) {
		keyPEM, err = getFile(keyFilename())
		return
	})
	err = grp.Err()
	return
}

func deployerCredsFromGCS() (*gce.Config, error) {
	ctx := context.Background()
	sc, err := storage.NewClient(ctx)
	if err != nil {
		return nil, err
	}
	slurp := func(key string) ([]byte, error) {
		const bucket = "camlistore-website-resource"
		rc, err := sc.Bucket(bucket).Object(key).NewReader(ctx)
		if err != nil {
			return nil, fmt.Errorf("Error fetching GCS object %q in bucket %q: %v", key, bucket, err)
		}
		defer rc.Close()
		return ioutil.ReadAll(rc)
	}
	var cfg gce.Config
	data, err := slurp("launcher-config.json")
	if err != nil {
		return nil, err
	}
	if err := json.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("Could not JSON decode camli GCE launcher config: %v", err)
	}
	return &cfg, nil
}

func NewGCS(name string, info map[string]string) (Backend, error) {
	b := &gcsBackend{
		name:       name,
		bucketName: info["bucket"],
	}
	keyJSON := []byte(info["key"])

	if b.bucketName == "" {
		return nil, fmt.Errorf("blobstore: missing Google Cloud Storage bucket param for %s", name)
	}
	if len(keyJSON) == 0 {
		return nil, fmt.Errorf("blobstore: missing Google Cloud Storage key JSON param for %s", name)
	}

	jwtToken, err := google.JWTConfigFromJSON(keyJSON, "https://www.googleapis.com/auth/devstorage.read_write")
	if err != nil {
		return nil, fmt.Errorf("blobstore: error loading Google Cloud Storage JSON key: %s", err)
	}
	tokenSource := jwtToken.TokenSource(context.Background())

	// Test getting an OAuth token so we can disambiguate an issue with the
	// token and an issue with the bucket permissions below.
	if _, err := tokenSource.Token(); err != nil {
		return nil, fmt.Errorf("blobstore: error getting Google Cloud Storage OAuth token: %s", err)
	}

	pemBlock, _ := pem.Decode(jwtToken.PrivateKey)
	privateKey, err := x509.ParsePKCS8PrivateKey(pemBlock.Bytes)
	if err != nil {
		return nil, fmt.Errorf("blobstore: error decoding Google Cloud Storage private key: %s", err)
	}
	rsaPrivateKey, ok := privateKey.(*rsa.PrivateKey)
	if !ok {
		return nil, fmt.Errorf("blobstore: unexpected Google Cloud Storage key type: %T", privateKey)
	}
	b.signOpts = func() *storage.SignedURLOptions {
		return &storage.SignedURLOptions{
			GoogleAccessID: jwtToken.Email,
			SignBytes: func(b []byte) ([]byte, error) {
				digest := sha256.Sum256(b)
				return rsa.SignPKCS1v15(rand.Reader, rsaPrivateKey, crypto.SHA256, digest[:])
			},
			Method:  "GET",
			Expires: time.Now().Add(10 * time.Minute),
		}
	}

	client, err := storage.NewClient(context.Background(), option.WithTokenSource(tokenSource))
	if err != nil {
		return nil, fmt.Errorf("blobstore: error creating Google Cloud Storage client: %s", err)
	}
	b.bucket = client.Bucket(b.bucketName)

	_, err = b.bucket.Attrs(context.Background())
	if err != nil {
		return nil, fmt.Errorf("blobstore: error checking Google Cloud Storage bucket %q existence, ensure that it exists and Owner access for %s is included the bucket ACL: %q", b.bucketName, jwtToken.Email, err)
	}
	return b, nil
}

func init() {
	client, err := storage.NewClient(context.Background())
	if err != nil {
		log.Fatalf("Unable to get storage client: %v", err)
	}
	bucket = client.Bucket(bucketName)

}

func upload(srcPath string) {
	if !*flagUpload {
		return
	}
	destName := strings.Replace(filepath.Base(srcPath), "camlistore", "camlistore-"+releaseDate.Format(fileDateFormat), 1)
	versionedTarball := "monthly/" + destName

	log.Printf("Uploading %s/%s ...", bucket, versionedTarball)

	ts, err := tokenSource(bucket)
	if err != nil {
		log.Fatal(err)
	}
	ctx := context.Background()
	stoClient, err := storage.NewClient(ctx, option.WithTokenSource(ts), option.WithHTTPClient(oauth2.NewClient(ctx, ts)))
	if err != nil {
		log.Fatal(err)
	}
	w := stoClient.Bucket(bucket).Object(versionedTarball).NewWriter(ctx)
	w.ACL = publicACL(project)
	w.CacheControl = "no-cache" // TODO: remove for non-tip releases? set expirations?
	contentType := "application/x-gtar"
	if strings.HasSuffix(versionedTarball, ".zip") {
		contentType = "application/zip"
	}
	w.ContentType = contentType
	csw := sha256.New()
	mw := io.MultiWriter(w, csw)

	src, err := os.Open(srcPath)
	if err != nil {
		log.Fatal(err)
	}
	defer src.Close()

	if _, err := io.Copy(mw, src); err != nil {
		log.Fatalf("io.Copy: %v", err)
	}
	if err := w.Close(); err != nil {
		log.Fatalf("closing GCS storage writer: %v", err)
	}
	log.Printf("Uploaded monthly tarball to %s", versionedTarball)

	// And upload the corresponding checksum
	checkSumFile := versionedTarball + ".sha256"
	sum := fmt.Sprintf("%x", csw.Sum(nil))
	w = stoClient.Bucket(bucket).Object(checkSumFile).NewWriter(ctx)
	w.ACL = publicACL(project)
	w.CacheControl = "no-cache" // TODO: remove for non-tip releases? set expirations?
	w.ContentType = "text/plain"
	if _, err := io.Copy(w, strings.NewReader(sum)); err != nil {
		log.Fatalf("error uploading checksum %v: %v", checkSumFile, err)
	}
	if err := w.Close(); err != nil {
		log.Fatalf("closing GCS storage writer: %v", err)
	}
	log.Printf("Uploaded monthly tarball checksum to %s", checkSumFile)
}

func ExampleBucketHandle_Objects() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	it := client.Bucket("my-bucket").Objects(ctx, nil)
	_ = it // TODO: iterate using Next or NextPage.
}

func ExampleObjectHandle_NewWriter() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	wc := client.Bucket("bucketname").Object("filename1").NewWriter(ctx)
	_ = wc // TODO: Use the Writer.
}

func setup(t *testing.T) *storage.Client {
	ctx := context.Background()

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

func ExampleClient_Buckets() {
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		// TODO: handle error.
	}
	it := client.Bucket("my-bucket")
	_ = it // TODO: iterate using Next or iterator.Pager.
}