Scenario:

Start docker container that exposes port 80. Should be mapped to port 4000 on the host system. Port bindings config:

4000 80

Worked in previous versions. Results in a container similar to:

abc12345as example/website-preview:latest   "/usr/sbin/apache2 -   5 seconds ago       Up 4 seconds        80/tcp                           sad_lovelace

Based on the config the mappings should look like this:

0.0.0.0:4000->80/tcp