Azure Storage Docs

Azure Blob Storage Container Concepts

A container in Azure Blob Storage is a logical grouping of related blobs. Think of it as a folder in a file system, though it's important to remember that Blob Storage is a flat namespace and doesn't support true nested folders. Containers provide a way to organize and manage your data.

Key Characteristics of Containers

• Root Level Organization: Containers are created at the root level of a storage account.
• Naming Conventions: Container names must start with a letter or number, and can contain only lowercase letters, numbers, and hyphens. They must be between 3 and 63 characters long and end with a letter or number.
• Uniqueness: Container names must be unique within a storage account.
• Access Control: Access to a container and its blobs is managed through permissions. Public access can be configured at the container level for anonymous read access.
• Metadata: Containers can have associated metadata, which is a set of key-value pairs that you can use to store custom information about the container.
• Leasing: Containers can be leased, which provides a way to manage exclusive write access to a container.

Public Access Levels

Azure Blob Storage offers several options for controlling public access to your containers and blobs:

• Private (No Anonymous Access): This is the default setting. Only authenticated users with appropriate permissions can access the container and its blobs.
• Blob (Anonymous Read Access for Blobs): In this mode, anonymous users can read blobs within the container, but they cannot access container metadata or list blobs. Each blob must be explicitly granted read access.
• Container (Anonymous Read Access for Container and Blobs): With this setting, anonymous users can list blobs within the container and read the blobs themselves. However, they cannot access container metadata.

Container Operations

You can perform various operations on containers using the Azure portal, Azure CLI, Azure PowerShell, or storage SDKs:

• Create: Create a new container.
• List: List all containers within a storage account.
• Get Properties: Retrieve metadata and properties of a container.
• Set Metadata: Update the metadata associated with a container.
• Set Public Access: Change the public access level of a container.
• Delete: Delete a container and all its contents.

Example: Creating a Container using Azure CLI

az storage container create \
    --name my-sample-container \
    --account-name mystorageaccount \
    --auth-mode login
                    

Example: Setting Public Access to Blob Level

az storage container set-public-access \
    --name my-sample-container \
    --account-name mystorageaccount \
    --public-access blob \
    --auth-mode login
                    

Best Practices

• Organize your blobs logically into containers to improve manageability and control access.
• Use descriptive container names.
• Carefully manage public access settings to protect your data.
• Leverage container metadata for custom tagging and organization.