Publishing ports to host via port-mapping within QM does not work

[raballew]

If you have to run multiple applications all listening on the same port within QM that expose a service to another host an intuitive approach to this would be using port mapping (8080:80, 8081:80) to resolve any conflicts and then publishing those ports:

Example: Port mapping does not work

Within QM /etc/containers/systemd/nginx-1.container:

[Container]
Image=localhost/nginx
PublishPort=8080:80

Within QM /etc/containers/systemd/nginx-2.container:

[Container]
Image=localhost/nginx
PublishPort=8081:80

On the host /etc/containers/systemd/qm.container.d/publish-port.conf:

[Container]
PublishPort=8080:8080
PublishPort=8081:8081

But this does not work even though the QM container publishes those ports.

curl 127.0.0.1:8080
curl: (7) Failed to connect to 127.0.0.1 port 8080: Connection refused

Instead one has to use host networking which disables port-mapping and therefore only one application can be started as they both would try to bind the same port:

Example: Only one application starts

Within QM /etc/containers/systemd/nginx-1.container:

[Container]
Image=localhost/nginx
Network=host

Within QM /etc/containers/systemd/nginx-2.container:

[Container]
Image=localhost/nginx
Network=host

On the host /etc/containers/systemd/qm.container.d/publish-port.conf:

[Container]
PublishPort=80

One application does not start:

podman ps -a
CONTAINER ID  IMAGE                                            COMMAND               CREATED         STATUS                     PORTS                 NAMES
538e1cf144d9  docker.io/library/nginx:latest                   nginx -g daemon o...  10 seconds ago  Up 10 seconds              80/tcp                frosty_poitras
afe9e0622fc1  docker.io/library/nginx:latest                   nginx -g daemon o...  6 seconds ago   Exited (1) 4 seconds ago   80/tcp                goofy_ellis