Re:Accidental complexity, essential complexity, and Kubernetes
by paulgb on Monday September 05, 2022 @06:42PM
(#32730357)
The Dockerfile doesn't specify volumes, those are configured at runtime. In the case of Kubernetes, they're configured in the pod spec.
As for ports, EXPOSE in a Dockerfile is basically just documentation/metadata. In practice ports are exposed at runtime (if using docker) or by configuring services (if using Kubernetes), and these are unaffected by whether a port is exposed in the dockerfile.
IMHO this is how it should be -- if I'm running a containerized database or web server, I want to be able to specify the port that the rest of the world sees it as, I don't want the container creator to decide that.
As for ports, EXPOSE in a Dockerfile is basically just documentation/metadata. In practice ports are exposed at runtime (if using docker) or by configuring services (if using Kubernetes), and these are unaffected by whether a port is exposed in the dockerfile.
IMHO this is how it should be -- if I'm running a containerized database or web server, I want to be able to specify the port that the rest of the world sees it as, I don't want the container creator to decide that.