AzureBlob

Azure Blob client and Active Storage adapter to replace the now abandoned azure-storage-blob

An Active Storage is supplied, but the gem is Rails agnostic and can be used in any Ruby project.

To migrate from azure-storage-blob to azure-blob:

1. Replace azure-storage-blob in your Gemfile with azure-blob
2. Run bundle install
3. Change the AzureStorage service to AzureBlob in your Active Storage config (config/storage.yml)
4. Restart or deploy the app.

Example config:

microsoft:
  service: AzureBlob
  storage_account_name: account_name
  storage_access_key: SECRET_KEY
  container: container_name

AzureBlob supports managed identities on :

• Azure VM
• App Service
• Azure Functions (Untested but should work)
• Azure Containers (Untested but should work)

AKS support will likely require more work. Contributions are welcome.

To authenticate through managed identities instead of a shared key, omit storage_access_key from your storage.yml file and pass in the identity principal_id.

ActiveStorage config example:

prod:
  service: AzureBlob
  container: container_name
  storage_account_name: account_name
  principal_id: 71b34410-4c50-451d-b456-95ead1b18cce

To use Azurite, pass the storage_blob_host config key with the Azurite URL (http://127.0.0.1:10000/devstoreaccount1 by default) and the Azurite credentials (devstoreaccount1 and Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw== by default).

Example:

dev:
  service: AzureBlob
  container: container_name
  storage_account_name: devstoreaccount1
  storage_access_key: "Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw=="
  storage_blob_host: http://127.0.0.1:10000/devstoreaccount1

You'll have to create the container before you can start uploading files. You can do so using Azure CLI, Azure Storage Explorer, or by running:

bin/rails runner "ActiveStorage::Blob.service.client.tap{|client| client.create_container unless client.get_container_properties.present?}.tap { |client| puts 'done!' if client.get_container_properties.present?}"

Make sure that config.active_storage.service = :dev is set to your azurite configuration. Container names can't have any special characters, or you'll get an error.

Instantiate a client with your account name, an access key and the container name:

client = AzureBlob::Client.new(
      account_name: @account_name,
      access_key: @access_key,
      container: @container,
    )

path = "some/new/file"

# Upload
client.create_block_blob(path, "Hello world!")

# Download
client.get_blob(path) #=> "Hello world!"

# Delete
client.delete_blob(path)

For the full list of methods: https://www.rubydoc.info/gems/azure-blob/AzureBlob/Client

The client is configured to raise an error early for missing credentials, causing it to crash before becoming healthy. This behavior can sometimes be undesirable, such as during assets precompilation.

To enable lazy loading and ignore missing credentials, set the lazy option:

AzureBlob::Client.new(account_name: nil, access_key: nil, container: nil, lazy: true)

or add lazy: true to your config/storage.yml for Active Storage.

A dev environment is supplied through Nix with devenv.

1. Install devenv.
2. Enter the dev environment by cd into the repo and running devenv shell (or direnv allow if you are a direnv user).
3. Log into azure CLI with az login
4. terraform init
5. terraform apply This will generate the necessary infrastructure on azure.
6. Generate devenv.local.nix with your private key and container information: generate-env-file
7. If you are using direnv, the environment will reload automatically. If not, exit the shell and reopen it by hitting and running devenv shell again.

To test with Entra ID, the AZURE_ACCESS_KEY environment variable must be unset and the code must be ran or proxied through a VPS with the proper roles.

For cost saving, the terraform variable create_vm and create_app_service are false by default. To create the VPS and App service, Create a var file var.tfvars containing:

create_vm = true
create_app_service = true

and re-apply terraform: terraform apply -var-file=var.tfvars.

This will create the VPS and required managed identities.

bin/rake test_azure_vm and bin/rake test_app_service will establish a VPN connection to the VM or App service container and run the test suite. You might be prompted for a sudo password when the VPN starts (sshuttle).

After you are done, run terraform again without the var file (terraform apply) to destroy the VPS and App service application.

Some tests copied over from Rails don't clean after themselves. A rake task is provided to empty your containers and keep cost low: bin/rake flush_test_container

If you prefer not using devenv/nix:

Ensure your version of Ruby fit the minimum version in azure-blob.gemspec

and setup those Env variables:

• AZURE_ACCOUNT_NAME
• AZURE_ACCESS_KEY
• AZURE_PRIVATE_CONTAINER
• AZURE_PUBLIC_CONTAINER

The gem is available as open source under the terms of the MIT License.