AzureBlob

This gem was built to replace azure-storage-blob (deprecated) in Active Storage, but was written to be Rails agnostic.

Active Storage

Migration

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

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

Managed Identity (Entra ID)

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.

It is recommended to add the identity’s principal_id to the config.

ActiveStorage config example:

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

Standalone

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) #=&gt; "Hello world!"

# Delete
client.delete_blob(path)

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

Contributing

Dev environment

A dev environment is supplied through Nix with devenv.

Install devenv.
Enter the dev environment by cd into the repo and running devenv shell (or direnv allow if you are a direnv user).
Log into azure CLI with az login
terraform init
terraform apply This will generate the necessary infrastructure on azure.
Generate devenv.local.nix with your private key and container information: generate-env-file
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.

Entra ID

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 is false by default.
To create the VPS, Create a var file var.tfvars containing:

create_vm = 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.

Cleanup

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

Run without devenv/nix

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

License

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

Modules

Classes