# BLOB Storing Azure Provider

BLOB Storing Azure Provider can store BLOBs in [Azure Blob storage](https://azure.microsoft.com/en-us/services/storage/blobs/).

> Read the [BLOB Storing document](Blob-Storing.md) to understand how to use the BLOB storing system. This document only covers how to configure containers to use a Azure BLOB as the storage provider.

## Installation

Use the ABP CLI to add [Volo.Abp.BlobStoring.Azure](https://www.nuget.org/packages/Volo.Abp.BlobStoring.Azure) NuGet package to your project:

* Install the [ABP CLI](https://docs.abp.io/en/abp/latest/CLI) if you haven't installed before.
* Open a command line (terminal) in the directory of the `.csproj` file you want to add the `Volo.Abp.BlobStoring.Azure` package.
* Run `abp add-package Volo.Abp.BlobStoring.Azure` command.

If you want to do it manually, install the [Volo.Abp.BlobStoring.Azure](https://www.nuget.org/packages/Volo.Abp.BlobStoring.Azure) NuGet package to your project and add `[DependsOn(typeof(AbpBlobStoringAzureModule))]` to the [ABP module](Module-Development-Basics.md) class inside your project.

## Configuration

Configuration is done in the `ConfigureServices` method of your [module](Module-Development-Basics.md) class, as explained in the [BLOB Storing document](Blob-Storing.md).

**Example: Configure to use the azure storage provider by default**

````csharp
Configure<AbpBlobStoringOptions>(options =>
{
    options.Containers.ConfigureDefault(container =>
    {
        container.UseAzure(azure =>
        {
            azure.ConnectionString = "your azure connection string";
            azure.ContainerName = "your azure container name";
            azure.CreateContainerIfNotExists = false;
        });
    });
});
````

> See the [BLOB Storing document](Blob-Storing.md) to learn how to configure this provider for a specific container.

### Options

* **ConnectionString** (string): A connection string includes the authorization information required for your application to access data in an Azure Storage account at runtime using Shared Key authorization. Please refer to Azure documentation: https://docs.microsoft.com/en-us/azure/storage/common/storage-configure-connection-string
* **ContainerName** (string): You can specify the container name in azure. If this is not specified, it uses the name of the BLOB container defined with the `BlogContainerName` attribute (see the [BLOB storing document](Blob-Storing.md)). Please note that Azure has some **rules for naming containers**. A container name must be a valid DNS name, conforming to the [following naming rules](https://docs.microsoft.com/en-us/rest/api/storageservices/naming-and-referencing-containers--blobs--and-metadata#container-names):
    * Container names must start or end with a letter or number, and can contain only letters, numbers, and the dash (-) character.
    * Every dash (-) character must be immediately preceded and followed by a letter or number; consecutive dashes are not permitted in container names.
    * All letters in a container name must be **lowercase**.
    * Container names must be from **3** through **63** characters long.
* **CreateContainerIfNotExists** (bool): Default value is `false`, If a container does not exist in azure, `AzureBlobProvider` will try to create it.


## Azure Blob Name Calculator

Azure Blob Provider organizes BLOB name and implements some conventions. The full name of a BLOB is determined by the following rules by default:

* Appends `host` string if [current tenant](Multi-Tenancy.md) is `null` (or multi-tenancy is disabled for the container - see the [BLOB Storing document](Blob-Storing.md) to learn how to disable multi-tenancy for a container).
* Appends `tenants/<tenant-id>` string if current tenant is not `null`.
* Appends the BLOB name.

## Other Services

* `AzureBlobProvider` is the main service that implements the Azure BLOB storage provider, if you want to override/replace it via [dependency injection](Dependency-Injection.md) (don't replace `IBlobProvider` interface, but replace `AzureBlobProvider` class).
* `IAzureBlobNameCalculator` is used to calculate the full BLOB name (that is explained above). It is implemented by the `DefaultAzureBlobNameCalculator` by default.