In the last lecture, we started a container which also exposed a port (port 80).
I just want to clarify again, that EXPOSE 80 in the Dockerfile in the end is optional. It documents that a process in the container will expose this port. But you still need to then actually expose the port with -p when running docker run. So technically, -p is the only required part when it comes to listening on a port. Still, it is a best practice to also add EXPOSE in the Dockerfile to document this behavior.
As an additional quick side-note: For all docker commands where an ID can be used, you don’t always have to copy / write out the full id.
You can also just use the first (few) character(s) – just enough to have a unique identifier.
So instead of
docker run abcdefg
you could also run
docker run abc
or, if there’s no other image ID starting with “a”, you could even run just:
docker run a
This applies to ALL Docker commands where IDs are needed.
