feat(api): load API key through systemd credentials with env fallback

[blackxored]

Description

On Linux systems, be a well-behaved daemon and prefer systemd credential api-key if passed to the service. This is done through a file, access is checked by the kernel, and there's no process inheritance, TL;DR is more secure than env vars. See: systemd Credentials.

It would still fallback to the API_KEY env var as there's no need for this to be a breaking change.

To-Dos

• Disclosed any use of AI (see our policy)
• Successful build pnpm build
• Translation keys pnpm i18n:extract
• Database migration (if required)

[M0NsTeRRR]

Hi @blackxored,

Instead of creating a new apiKeyFromEnvOrCred function, could you move the stringOrReadFileFromEnv function from server/datasource.ts to server/utils/env.ts? This way, we can reuse the same logic where needed.

Additionally, since this feature is similar to Docker secrets, it would be great to support both approaches simultaneously. By default, Docker secrets are mounted at /run/secrets. I think adding ENV CREDENTIALS_DIRECTORY="/run/secrets" to the Dockerfile would be enough to make them work out of the box. What do you think?

Reference: Docker Secrets Documentation

[benja1006]

I agree, it would work nicely to place the systemd credentials into /run/secrets, then we can access them using _FILE appended to the DB username, password and name. This would integrate cleanly into the default postgres behavior as well