This article shows how to delete blobs using theAzure Storage client module for Go, and how to restoresoft-deleted blobs during the retention period.

Prerequisites

• Azure subscription -create one for free
• Azure storage account -create a storage account
• Go 1.18+

Set up your environment

If you don't have an existing project, this section shows how to set up a project to work with the Azure Blob Storage client module for Go. The steps include module installation, addingimport paths, and creating an authorized client object. For details, seeGet started with Azure Blob Storage and Go.

Install modules

Install theazblob module using the following command:

go get github.com/Azure/azure-sdk-for-go/sdk/storage/azblob

To authenticate with Microsoft Entra ID (recommended), install theazidentity module using the following command:

go get github.com/Azure/azure-sdk-for-go/sdk/azidentity

Add import paths

In your code file, add the following import paths:

import (    "github.com/Azure/azure-sdk-for-go/sdk/azidentity""github.com/Azure/azure-sdk-for-go/sdk/storage/azblob")

These import paths represent the minimum needed to get started. Some code examples in this article might require additional import paths. For specific details and example usage, seeCode samples.

Create a client object

To connect an app to Blob Storage, create a client object usingazblob.NewClient. The following example shows how to create a client object usingDefaultAzureCredential for authorization:

func getServiceClientTokenCredential(accountURL string) *azblob.Client {    // Create a new service client with token credential    credential, err := azidentity.NewDefaultAzureCredential(nil)    handleError(err)    client, err := azblob.NewClient(accountURL, credential, nil)    handleError(err)    return client}

Authorization

The authorization mechanism must have the necessary permissions to delete a blob, or to restore a soft-deleted blob. For authorization with Microsoft Entra ID (recommended), you need Azure RBAC built-in roleStorage Blob Data Contributor or higher. To learn more, see the authorization guidance forDelete Blob (REST API) andUndelete Blob (REST API).

Delete a blob

To delete a blob, call the following method:

• DeleteBlob

The following example deletes a blob:

func deleteBlob(client *azblob.Client, containerName string, blobName string) {    // Delete the blob    _, err := client.DeleteBlob(context.TODO(), containerName, blobName, nil)    handleError(err)}

If the blob has any associated snapshots, you must delete all of its snapshots to delete the blob. The following example deletes a blob and its snapshots:

func deleteBlobWithSnapshots(client *azblob.Client, containerName string, blobName string) {    // Delete the blob and its snapshots    _, err := client.DeleteBlob(context.TODO(), containerName, blobName, &blob.DeleteOptions{        DeleteSnapshots: to.Ptr(blob.DeleteSnapshotsOptionTypeInclude),    })    handleError(err)}

To deleteonly the snapshots and not the blob itself, you can pass the valueDeleteSnapshotsOptionTypeOnly to theDeleteSnapshots parameter.

Restore a deleted blob

Blob soft delete protects an individual blob and its versions, snapshots, and metadata from accidental deletes or overwrites by maintaining the deleted data in the system for a specified period of time. During the retention period, you can restore the blob to its state at deletion. After the retention period expires, the blob is permanently deleted. For more information about blob soft delete, seeSoft delete for blobs.

You can use the Azure Storage client libraries to restore a soft-deleted blob or snapshot.

How you restore a soft-deleted blob depends on whether or not your storage account has blob versioning enabled. For more information on blob versioning, seeBlob versioning. See one of the following sections, depending on your scenario:

• Blob versioning is not enabled
• Blob versioning is enabled

Restore soft-deleted objects when versioning is disabled

To restore deleted blobs when versioning is disabled, call the following method:

• UndeleteBlob

This method restores the content and metadata of a soft-deleted blob and any associated soft-deleted snapshots. Calling this method for a blob that hasn't been deleted has no effect.

func restoreDeletedBlob(client *azblob.Client, containerName string, blobName string) {    // Reference the blob as a client object    blobClient := client.ServiceClient().NewContainerClient(containerName).NewBlobClient(blobName)    // Restore the deleted blob    _, err := blobClient.Undelete(context.TODO(), &blob.UndeleteOptions{})    handleError(err)}

Restore soft-deleted objects when versioning is enabled

If a storage account is configured to enable blob versioning, deleting a blob causes the current version of the blob to become the previous version. To restore a soft-deleted blob when versioning is enabled, copy a previous version over the base blob. You can use the following method:

• StartCopyFromURL

The following code example identifies a version of a deleted blob, and restores that version by copying it to the base blob:

func restoreDeletedBlobVersion(client *azblob.Client, containerName string, blobName string, versionID string) {    // Reference the blob as a client object    baseBlobClient := client.ServiceClient().NewContainerClient(containerName).NewBlobClient(blobName)    blobVersionClient, err := baseBlobClient.WithVersionID(versionID)    handleError(err)    // Restore the blob version by copying it to the base blob    _, err = baseBlobClient.StartCopyFromURL(context.TODO(), blobVersionClient.URL(), nil)    handleError(err)}

Resources

To learn more about how to delete blobs and restore deleted blobs using the Azure Blob Storage client module for Go, see the following resources.

Code samples

• Viewcode samples from this article (GitHub)

REST API operations

The Azure SDK for Go contains libraries that build on top of the Azure REST API, allowing you to interact with REST API operations through familiar Go paradigms. The client library methods for deleting blobs and restoring deleted blobs use the following REST API operations:

• Delete Blob (REST API)
• Undelete Blob (REST API)

Client module resources

• Client module reference documentation
• Client module source code
• Package (pkg.go.dev)

See also

• Soft delete for blobs
• Blob versioning

Related content

• This article is part of the Blob Storage developer guide for Go. To learn more, see the full list of developer guide articles atBuild your Go app.