Dokku Port Mapping

After creating your app, it’s possible that either dokku didn’t auto-detect the ports properly or the port has changed. In this case, it will be necessary to fallback to manual port mapping.

Show existing ports

dokku proxy:report my-app

Example:

=====> minio-console proxy information
       Proxy enabled:                 true
       Proxy port map:                http:80:80
       Proxy type:                    nginx

The port maps follow the docker standard, http:host-port:container-port. host port is the entrypoint into the dokku server, it should be 80 for http. container port is the port the container serves on, common examples include 80, 5000, and 8080.

Setting up port mappings

# if not enabled, enable the proxy
dokku proxy:enable my-app

# replace 5000 with the port your container is using
dokku proxy:ports-set my-app http:80:5000

# rebuild the nginx configuration to reflect new port mappings
dokku proxy:build-config my-app

If things are still not working, maybe you forgot to run:

dokku traefik:enable my-app

which should be done when you create an app. Otherwise you might want to check the nginx config to verify it has your changes

dokku nginx:show-config my-app

The upstream at the bottom should be using the container port and the listen clauses should show the host ports. If this looks good but it still doesn’t work, there is likely an issue with the container, test it locally.