What is a recommended best practice when handling authentication for a new microservice retrieving missed events?

The recommended best practice for handling authentication, especially in the context of a new microservice retrieving missed events, is to keep the API key in a secret management service. This approach enhances security by ensuring that sensitive credentials are not hard-coded into the application code or exposed to public access. Secret management services provide a centralized solution for storing, accessing, and managing secrets such as API keys, making them easily accessible to authorized services while minimizing the risk of exposure.

Using a secret management service helps enforce strict access controls and auditing capabilities, thereby reducing the likelihood of unauthorized access or credential leaks. This practice aligns with the principles of security best practices, especially in microservices architecture where services may need to authenticate with each other.

The other options present some risks or less desirable practices. Keeping the API key public, for instance, exposes the application to potential abuse and security vulnerabilities. Creating a general API for all services may lead to a monolithic design, which negates the advantages of microservices. Lastly, relying solely on standard usernames and passwords can be insufficient by today’s security standards, especially when there are more secure methods available, such as API keys stored in secret management solutions.