registry/storage/driver/azure: fix Move method

Something seems broken on azure/azure sdk side - it is currently not
possible to copy a blob of type AppendBlob using `CopyFromURL`.
Using the AppendBlob client via NewAppendBlobClient does not work
either.

According to Azure the correct way to do this is by using
StartCopyFromURL. Because this is an async operation, we need to do
polling ourselves. A simple backoff mechanism is used, where during each
iteration, the configured delay is multiplied by the retry number.

Also introduces two new config options for the Azure driver:
copy_status_poll_max_retry, and copy_status_poll_delay.

Signed-off-by: Flavian Missi <fmissi@redhat.com>

docs/configuration.md

@@ -103,6 +103,8 @@ storage:
       clientid: client_id_string
       tenantid: tenant_id_string
       secret: secret_string
+    copy_status_poll_max_retry: 10
+    copy_status_poll_delay: 100ms
   gcs:
     bucket: bucketname
     keyfile: /path/to/keyfile

docs/storage-drivers/azure.md

@@ -9,11 +9,13 @@ An implementation of the `storagedriver.StorageDriver` interface which uses [Mic
 ## Parameters
 
 | Parameter                          | Required | Description                                                                                                                                                                                                                                                         |
-|:--------------|:---------|:--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|:-----------------------------------|:---------|:--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `accountname`                      | yes      | Name of the Azure Storage Account.                                                                                                                                                                                                                                  |
 | `accountkey`                       | yes      | Primary or Secondary Key for the Storage Account.                                                                                                                                                                                                                   |
 | `container`                        | yes      | Name of the Azure root storage container in which all registry data is stored. Must comply the storage container name [requirements](https://docs.microsoft.com/rest/api/storageservices/fileservices/naming-and-referencing-containers--blobs--and-metadata). For example, if your url is `https://myaccount.blob.core.windows.net/myblob` use the container value of `myblob`.|
 | `realm`                            | no       | Domain name suffix for the Storage Service API endpoint. For example realm for "Azure in China" would be `core.chinacloudapi.cn` and realm for "Azure Government" would be `core.usgovcloudapi.net`. By default, this is `core.windows.net`.                        |
+| `copy_status_poll_max_retry`       | no       | Max retry number for polling of copy operation status. Retries use a simple backoff algorithm where each retry number is multiplied by `copy_status_poll_delay`, and this number is used as the delay. Set to -1 to disable retries and abort if the copy does not complete immediately. Defaults to 5.                |
+| `copy_status_poll_delay`            | no       | Time to wait between retries for polling of copy operation status. This time is multiplied by N on each retry, where N is the retry number. Defaults to 100ms |
 
 
 ## Related information

registry/storage/driver/azure/azure.go

@@ -21,9 +21,8 @@ import (
 	"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob/container"
 )
 
-const driverName = "azure"
-
 const (
+	driverName   = "azure"
 	maxChunkSize = 4 * 1024 * 1024
 )
 
@@ -31,6 +30,8 @@ type driver struct {
 	azClient               *azureClient
 	client                 *container.Client
 	rootDirectory          string
+	copyStatusPollMaxRetry int
+	copyStatusPollDelay    time.Duration
 }
 
 type baseEmbed struct{ base.Base }
@@ -59,11 +60,19 @@ func New(params *Parameters) (*Driver, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	copyStatusPollDelay, err := time.ParseDuration(params.CopyStatusPollDelay)
+	if err != nil {
+		return nil, err
+	}
+
 	client := azClient.ContainerClient()
 	d := &driver{
 		azClient:               azClient,
 		client:                 client,
 		rootDirectory:          params.RootDirectory,
+		copyStatusPollMaxRetry: params.CopyStatusPollMaxRetry,
+		copyStatusPollDelay:    copyStatusPollDelay,
 	}
 	return &Driver{baseEmbed: baseEmbed{Base: base.Base{StorageDriver: d}}}, nil
 }
@@ -282,7 +291,7 @@ func (d *driver) Move(ctx context.Context, sourcePath string, destPath string) e
 		return err
 	}
 	destBlobRef := d.client.NewBlockBlobClient(d.blobName(destPath))
-	_, err = destBlobRef.CopyFromURL(ctx, sourceBlobURL, nil)
+	resp, err := destBlobRef.StartCopyFromURL(ctx, sourceBlobURL, nil)
 	if err != nil {
 		if is404(err) {
 			return storagedriver.PathNotFoundError{Path: sourcePath}
@@ -290,6 +299,39 @@ func (d *driver) Move(ctx context.Context, sourcePath string, destPath string) e
 		return err
 	}
 
+	copyStatus := *resp.CopyStatus
+
+	if d.copyStatusPollMaxRetry == -1 && copyStatus == blob.CopyStatusTypePending {
+		destBlobRef.AbortCopyFromURL(ctx, *resp.CopyID, nil)
+		return nil
+	}
+
+	retryCount := 1
+	for copyStatus == blob.CopyStatusTypePending {
+		props, err := destBlobRef.GetProperties(ctx, nil)
+		if err != nil {
+			return err
+		}
+
+		if retryCount >= d.copyStatusPollMaxRetry {
+			destBlobRef.AbortCopyFromURL(ctx, *props.CopyID, nil)
+			return fmt.Errorf("max retries for copy polling reached, aborting copy")
+		}
+
+		copyStatus = *props.CopyStatus
+		if copyStatus == blob.CopyStatusTypeAborted || copyStatus == blob.CopyStatusTypeFailed {
+			if props.CopyStatusDescription != nil {
+				return fmt.Errorf("failed to move blob: %s", *props.CopyStatusDescription)
+			}
+			return fmt.Errorf("failed to move blob with copy id %s", *props.CopyID)
+		}
+
+		if copyStatus == blob.CopyStatusTypePending {
+			time.Sleep(d.copyStatusPollDelay * time.Duration(retryCount))
+		}
+		retryCount++
+	}
+
 	_, err = d.client.NewBlobClient(d.blobName(sourcePath)).Delete(ctx, nil)
 	return err
 }

registry/storage/driver/azure/azure_test.go

@@ -1,7 +1,9 @@
 package azure
 
 import (
+	"context"
 	"fmt"
+	"math/rand"
 	"os"
 	"strings"
 	"testing"
@@ -19,6 +21,8 @@ const (
 	envRootDirectory = "AZURE_ROOT_DIRECTORY"
 )
 
+var azureDriverConstructor func() (storagedriver.StorageDriver, error)
+
 // Hook up gocheck into the "go test" runner.
 func Test(t *testing.T) { check.TestingT(t) }
 
@@ -36,10 +40,10 @@ func init() {
 		value     *string
 		missingOk bool
 	}{
-		{envAccountName, &accountName, false},
+		{envAccountName, &accountName, true},
-		{envAccountKey, &accountKey, false},
+		{envAccountKey, &accountKey, true},
-		{envContainer, &container, false},
+		{envContainer, &container, true},
-		{envRealm, &realm, false},
+		{envRealm, &realm, true},
 		{envRootDirectory, &rootDirectory, true},
 	}
 
@@ -51,7 +55,7 @@ func init() {
 		}
 	}
 
-	azureDriverConstructor := func() (storagedriver.StorageDriver, error) {
+	azureDriverConstructor = func() (storagedriver.StorageDriver, error) {
 		parameters := map[string]interface{}{
 			"container":     container,
 			"accountname":   accountName,
@@ -77,6 +81,66 @@ func init() {
 	testsuites.RegisterSuite(azureDriverConstructor, skipCheck)
 }
 
+var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+func randStringRunes(n int) string {
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letterRunes[rand.Intn(len(letterRunes))]
+	}
+	return string(b)
+}
+
+func TestCommitAfterMove(t *testing.T) {
+	driver, err := azureDriverConstructor()
+	if err != nil {
+		t.Fatalf("unexpected error creating azure driver: %v", err)
+	}
+
+	contents := randStringRunes(4 * 1024 * 1024)
+	sourcePath := "/source/file"
+	destPath := "/dest/file"
+	ctx := context.Background()
+
+	defer driver.Delete(ctx, sourcePath)
+	defer driver.Delete(ctx, destPath)
+
+	writer, err := driver.Writer(ctx, sourcePath, false)
+	if err != nil {
+		t.Fatalf("unexpected error from driver.Writer: %v", err)
+	}
+
+	_, err = writer.Write([]byte(contents))
+	if err != nil {
+		t.Fatalf("writer.Write: unexpected error: %v", err)
+	}
+
+	err = writer.Commit()
+	if err != nil {
+		t.Fatalf("writer.Commit: unexpected error: %v", err)
+	}
+
+	err = writer.Close()
+	if err != nil {
+		t.Fatalf("writer.Close: unexpected error: %v", err)
+	}
+
+	_, err = driver.GetContent(ctx, sourcePath)
+	if err != nil {
+		t.Fatalf("driver.GetContent(sourcePath): unexpected error: %v", err)
+	}
+
+	err = driver.Move(ctx, sourcePath, destPath)
+	if err != nil {
+		t.Fatalf("driver.Move: unexpected error: %v", err)
+	}
+
+	_, err = driver.GetContent(ctx, destPath)
+	if err != nil {
+		t.Fatalf("GetContent(destPath): unexpected error: %v", err)
+	}
+}
+
 func TestParamParsing(t *testing.T) {
 	expectErrors := []map[string]interface{}{
 		{},

registry/storage/driver/azure/parser.go

@@ -9,6 +9,8 @@ import (
 
 const (
 	defaultRealm                  = "core.windows.net"
+	defaultCopyStatusPollMaxRetry = 5
+	defaultCopyStatusPollDelay    = "100ms"
 )
 
 type Credentials struct {
@@ -27,6 +29,8 @@ type Parameters struct {
 	Realm                  string      `mapstructure:"realm"`
 	RootDirectory          string      `mapstructure:"rootdirectory"`
 	ServiceURL             string      `mapstructure:"serviceurl"`
+	CopyStatusPollMaxRetry int         `mapstructure:"copy_status_poll_max_retry"`
+	CopyStatusPollDelay    string      `mapstructure:"copy_status_poll_delay"`
 }
 
 func NewParameters(parameters map[string]interface{}) (*Parameters, error) {
@@ -45,5 +49,11 @@ func NewParameters(parameters map[string]interface{}) (*Parameters, error) {
 	if params.ServiceURL == "" {
 		params.ServiceURL = fmt.Sprintf("https://%s.blob.%s", params.AccountName, params.Realm)
 	}
+	if params.CopyStatusPollMaxRetry == 0 {
+		params.CopyStatusPollMaxRetry = defaultCopyStatusPollMaxRetry
+	}
+	if params.CopyStatusPollDelay == "" {
+		params.CopyStatusPollDelay = defaultCopyStatusPollDelay
+	}
 	return &params, nil
 }