Docker Container Networking

Networking containers enable a containerized app to communicate with the outside world. In many cases a given app may be dependent on a database or multiple services. We can "expose" to enable these interactions.

Expose

Dockerfile

...
EXPOSE 8080 
...

We can also expose multiple ports

...
EXPOSE 80
EXPOSE 8080 
EXPOSE 5432
...

CLI and Run Time

At docker start

At docker run

docker run --expose=8080 --name="port-demo" test

Reference