Add Managed Identity option to azure storage

updates

pkg/storages/azure/folder.go

@@ -28,6 +28,7 @@ const (
 	BufferSizeSetting = "AZURE_BUFFER_SIZE"
 	MaxBuffersSetting = "AZURE_MAX_BUFFERS"
 	TryTimeoutSetting = "AZURE_TRY_TIMEOUT"
+	ClientIDSetting   = "AZURE_CLIENT_ID"
 	minBufferSize     = 1024
 	defaultBufferSize = 8 * 1024 * 1024
 	minBuffers        = 1
@@ -40,8 +41,9 @@ const (
 type AzureAuthType string
 
 const (
-	AzureAccessKeyAuth AzureAuthType = "AzureAccessKeyAuth"
-	AzureSASTokenAuth  AzureAuthType = "AzureSASTokenAuth"
+	AzureAccessKeyAuth       AzureAuthType = "AzureAccessKeyAuth"
+	AzureSASTokenAuth        AzureAuthType = "AzureSASTokenAuth"
+	AzureManagedIdentityAuth AzureAuthType = "AzureManagedIdentityAuth"
 )
 
 var SettingList = []string{
@@ -52,6 +54,7 @@ var SettingList = []string{
 	EndpointSuffix,
 	BufferSizeSetting,
 	MaxBuffersSetting,
+	ClientIDSetting,
 }
 
 func NewFolderError(err error, format string, args ...interface{}) storage.Error {
@@ -78,6 +81,31 @@ func NewFolder(
 	}
 }
 
+func getContainerClientWithManagedIndetity(
+	accountName string,
+	storageEndpointSuffix string,
+	containerName string,
+	timeout time.Duration,
+	clientID string) (*azblob.ContainerClient, error) {
+	cred, err := azidentity.NewManagedIdentityCredential(&azidentity.ManagedIdentityCredentialOptions{
+		ID: azidentity.ClientID(clientID),
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	containerURLString := fmt.Sprintf("https://%s.blob.%s/%s", accountName, storageEndpointSuffix, containerName)
+	_, err = url.Parse(containerURLString)
+	if err != nil {
+		return nil, NewFolderError(err, "Unable to parse service URL")
+	}
+
+	containerClient, err := azblob.NewContainerClient(containerURLString, cred, &azblob.ClientOptions{
+		Retry: policy.RetryOptions{TryTimeout: timeout},
+	})
+	return containerClient, err
+}
+
 func getContainerClientWithSASToken(
 	accountName string,
 	storageEndpointSuffix string,
@@ -136,9 +164,9 @@ func getContainerClient(
 	return containerClient, err
 }
 
-func configureAuthType(settings map[string]string) (AzureAuthType, string, string) {
+func configureAuthType(settings map[string]string) (AzureAuthType, string, string, string) {
 	var ok bool
-	var accountToken, accessKey string
+	var accountToken, accessKey, clientID string
 	var authType AzureAuthType
 
 	if accessKey, ok = settings[AccessKeySetting]; ok {
@@ -149,9 +177,11 @@ func configureAuthType(settings map[string]string) (AzureAuthType, string, strin
 		if !strings.HasPrefix(accountToken, "?") {
 			accountToken = "?" + accountToken
 		}
+	} else if clientID, ok = settings[ClientIDSetting]; ok {
+		authType = AzureManagedIdentityAuth
 	}
 
-	return authType, accountToken, accessKey
+	return authType, accountToken, accessKey, clientID
 }
 
 func ConfigureFolder(prefix string, settings map[string]string) (storage.Folder, error) {
@@ -161,7 +191,7 @@ func ConfigureFolder(prefix string, settings map[string]string) (storage.Folder,
 		return nil, NewCredentialError(AccountSetting)
 	}
 
-	authType, accountToken, accountKey := configureAuthType(settings)
+	authType, accountToken, accountKey, clientID := configureAuthType(settings)
 
 	var credential *azblob.SharedKeyCredential
 	var err error
@@ -199,6 +229,8 @@ func ConfigureFolder(prefix string, settings map[string]string) (storage.Folder,
 	var containerClient *azblob.ContainerClient
 	if authType == AzureSASTokenAuth {
 		containerClient, err = getContainerClientWithSASToken(accountName, storageEndpointSuffix, containerName, timeout, accountToken)
+	} else if authType == AzureManagedIdentityAuth {
+		containerClient, err = getContainerClientWithManagedIndetity(accountName, storageEndpointSuffix, containerName, timeout, clientID)
 	} else if authType == AzureAccessKeyAuth {
 		containerClient, err = getContainerClientWithAccessKey(accountName, storageEndpointSuffix, containerName, timeout, credential)
 	} else {

pkg/storages/azure/folder_test.go

@@ -2,6 +2,7 @@ package azure
 
 import (
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/wal-g/wal-g/pkg/storages/storage"
@@ -22,24 +23,47 @@ var ConfigureAuthType = configureAuthType
 
 func TestConfigureAccessKeyAuthType(t *testing.T) {
 	settings := map[string]string{AccessKeySetting: "foo"}
-	authType, accountToken, accessKey := ConfigureAuthType(settings)
+	authType, accountToken, accessKey, clientID := ConfigureAuthType(settings)
 	assert.Equal(t, authType, AzureAccessKeyAuth)
 	assert.Empty(t, accountToken)
 	assert.Equal(t, accessKey, "foo")
+	assert.Empty(t, clientID)
 }
 
 func TestConfigureSASTokenAuth(t *testing.T) {
 	settings := map[string]string{SasTokenSetting: "foo"}
-	authType, accountToken, accessKey := ConfigureAuthType(settings)
+	authType, accountToken, accessKey, clientID := ConfigureAuthType(settings)
 	assert.Equal(t, authType, AzureSASTokenAuth)
 	assert.Equal(t, accountToken, "?foo")
 	assert.Empty(t, accessKey)
+	assert.Empty(t, clientID)
 }
 
 func TestConfigureDefaultAuth(t *testing.T) {
 	settings := make(map[string]string)
-	authType, accountToken, accessKey := ConfigureAuthType(settings)
+	authType, accountToken, accessKey, clientID := ConfigureAuthType(settings)
 	assert.Empty(t, authType)
 	assert.Empty(t, accountToken)
 	assert.Empty(t, accessKey)
+	assert.Empty(t, clientID)
+}
+
+func TestConfigureManagedIdentityAuth(t *testing.T) {
+	settings := map[string]string{ClientIDSetting: "foo"}
+	authType, accountToken, accessKey, clientID := ConfigureAuthType(settings)
+	assert.Equal(t, authType, AzureManagedIdentityAuth)
+	assert.Empty(t, accountToken)
+	assert.Empty(t, accessKey)
+	assert.Equal(t, clientID, "foo")
+}
+func TestGetContainerClientWithManagedIdentity(t *testing.T) {
+	accountName := "test-account"
+	storageEndpointSuffix := "test-endpoint"
+	containerName := "test-container"
+	timeout := time.Minute
+	clientID := "test-client-id"
+
+	containerClient, err := getContainerClientWithManagedIndetity(accountName, storageEndpointSuffix, containerName, timeout, clientID)
+	assert.NoError(t, err)
+	assert.NotNil(t, containerClient)
 }