Introduction to Azure Blob Storage

Azure Blob Storage is Microsoft's object storage solution for the cloud. It is optimized for storing massive amounts of unstructured data, such as text or binary data. Blob storage can be used to serve images or documents directly to a browser, store files for distributed access, stream video and audio, write to log files, store data for backup and restore, disaster recovery, and archive.

Key features include:

  • Scalability and Cost-Effectiveness
  • High Availability and Durability
  • Security and Access Control
  • Global Reach

Getting Started

To begin using Azure Blob Storage, you need an Azure subscription and a storage account. Once created, you can interact with blobs via:

  • Azure Portal
  • Azure CLI
  • Azure PowerShell
  • Azure SDKs (for various programming languages)
  • REST API
Tip: For programmatic access, consider using the Azure SDKs which offer simplified APIs and robust error handling.

Core Blob Operations

Creating a Container

Containers are logical groupings of blobs. A storage account can contain an unlimited number of containers, but each container can hold an unlimited number of blobs.

REST API Example (Create Container)

PUT request to the container endpoint.

PUT https://myaccount.blob.core.windows.net/mycontainer?restype=container HTTP/1.1
Authorization: SharedKey myaccount:{"me=="}
Date: Tue, 29 Jul 2014 22:39:06 GMT
Content-Length: 0

Azure CLI Example

az storage container create --name mycontainer --account-name myaccount --auth-mode login

Uploading a Blob

Blobs can be of different types: block blobs, append blobs, and page blobs. Block blobs are the most common type and are suitable for storing text and binary data.

REST API Example (Upload Block Blob)

PUT request to the blob endpoint with the blob data in the request body.

PUT https://myaccount.blob.core.windows.net/mycontainer/myblob.txt?comp=block HTTP/1.1
Authorization: SharedKey myaccount:{"me=="}
Date: Tue, 29 Jul 2014 22:40:00 GMT
Content-Length: 11
x-ms-blob-type: BlockBlob

Hello World!

Azure CLI Example

az storage blob upload --account-name myaccount --container-name mycontainer --name myblob.txt --file <path-to-local-file> --auth-mode login

Downloading a Blob

Retrieve the content of a blob from Azure Blob Storage.

REST API Example (Download Blob)

GET request to the blob endpoint.

GET https://myaccount.blob.core.windows.net/mycontainer/myblob.txt HTTP/1.1
Authorization: SharedKey myaccount:{"me=="}
Date: Tue, 29 Jul 2014 22:41:00 GMT

Azure CLI Example

az storage blob download --account-name myaccount --container-name mycontainer --name myblob.txt --file <path-to-save-file> --auth-mode login

Deleting a Blob

Remove a blob from a container.

REST API Example (Delete Blob)

DELETE request to the blob endpoint.

DELETE https://myaccount.blob.core.windows.net/mycontainer/myblob.txt HTTP/1.1
Authorization: SharedKey myaccount:{"me=="}
Date: Tue, 29 Jul 2014 22:42:00 GMT

Azure CLI Example

az storage blob delete --account-name myaccount --container-name mycontainer --name myblob.txt --auth-mode login

Listing Blobs

Retrieve a list of blobs within a specific container.

REST API Example (List Blobs)

GET request to the container endpoint with the comp=list query parameter.

GET https://myaccount.blob.core.windows.net/mycontainer?comp=list HTTP/1.1
Authorization: SharedKey myaccount:{"me=="}
Date: Tue, 29 Jul 2014 22:43:00 GMT

Azure CLI Example

az storage blob list --account-name myaccount --container-name mycontainer --auth-mode login

Managing Access and Permissions

Control who can access your blobs using Shared Access Signatures (SAS), Access Control Lists (ACLs), and role-based access control (RBAC).

Note: Always apply the principle of least privilege when granting access to your storage resources.

Advanced Operations

Azure Blob Storage supports more advanced features such as:

  • Blob versioning and immutability policies for data protection and compliance.
  • Blob indexing for efficient querying of blobs based on metadata.
  • Hierarchical namespace for Azure Data Lake Storage Gen2 capabilities.
  • Access tiers (Hot, Cool, Archive) for cost optimization.
  • Blob snapshots for point-in-time backups.

Best Practices

  • Organize your data logically using containers and blob names.
  • Use appropriate blob types (block, append, page) for your workload.
  • Implement robust error handling and retry mechanisms in your applications.
  • Regularly review access policies and permissions.
  • Monitor storage usage and costs to optimize expenses.
  • Consider data redundancy options based on your availability requirements.