Custom Azure MySQL Authentication with Managed Identity in Django

Your approach to enabling Django to authenticate with Azure MySQL using Azure Managed Identity is technically sound. You're correctly extending the MySQL DatabaseWrapper class and overriding the get_connection_params method to inject the token-based authentication.

Reliability for Production

From a technical perspective, your implementation follows good practices:

1. You're using the async_unsafe decorator appropriately for the token retrieval method
2. You're properly extending the existing MySQL backend
3. The token refresh mechanism is handled by the Azure SDK

However, there are some considerations for production use:

• Connection Pooling: Since tokens expire every 30 minutes, you'll need to ensure connections are refreshed accordingly. The default Django connection handling might not be optimal for this scenario.
• Error Handling: Your implementation should include robust error handling for token retrieval failures.
• Performance Impact: Token retrieval adds overhead to connection establishment, which could impact performance under high load.

Integration Path

Based on the Django documentation regarding database backends, this functionality would be better suited as a standalone third-party Django database backend rather than being integrated into Django core. Here's why:

1. Django maintains official support for a limited set of database backends (MySQL, PostgreSQL, SQLite, Oracle)
2. There's an established ecosystem of third-party database backends for specialized use cases
3. Your implementation is specific to Azure services, which aligns with the third-party model

Recommendation

I recommend packaging this as a standalone third-party Django database backend, similar to other specialized backends like those for CockroachDB, Firebird, or Microsoft SQL Server mentioned in the Django documentation.

For production readiness, consider enhancing your implementation with:

PYTHONCopied
class DatabaseWrapper(DatabaseWrapper):
    def get_connection_params(self):
        kwargs = super().get_connection_params()
        settings_dict = self.settings_dict
        if settings_dict.get("CLIENTID"):
            try:
                clientid = settings_dict["CLIENTID"]
                kwargs["password"] = self._get_db_token(clientid)
            except Exception as e:
                # Log the error
                raise DatabaseError(f"Failed to retrieve Azure token: {str(e)}")
        return kwargs

    @async_unsafe
    def _get_db_token(self, clientid):
        credential = ManagedIdentityCredential(client_id=clientid)
        access_token = credential.get_token('https://ossrdbms-aad.database.windows.net/.default')
        return access_token.token

This approach would make your solution more robust for production environments while following Django's established patterns for database backend extensions.