

A superb image will have a health check endpoint set up in the dockerfile.
A good image will have a health check endpoint on either the service or another port that you can set up manually.
Most images will require you to manually devise some convoluted health check procedure using automated auth tokens.
All of my images fall into that latter category. You’re welcome.
(Ok, ok, I’m sorry. But you did just remind me that I need to code a health check endpoint and put it in the dockerfile.)

I don’t think a year old base is bad. Unless there’s an absolutely devastating CVE in something like the network stack or a particular shared library, any vulnerabilities in it will probably be just privilege escalations that wouldn’t have any effect unless you were allowing people shell access to the container. Obviously, the application itself can have a vulnerability, but that would be the case regardless of base image.