fixing passing port as a build argument to containers

[Gregory-Pereira]

Re-opening #258 on upstream branch because tests weren't working from my fork. Guessing this is some funkyness resulting from toggling actions off then back on in my fork.

I discovered when playing around with builds that the way we were passing PORT arguments wasnt working, because we both were exposing a static port number in the Containerfile and because we were passing the actual argument for it incorrectly:

# Tested from the `object_detection_python` model_server but all builds were the same
$ make PORT=20203 build
podman build --squash-all \
	  --build-arg PORT=20203 \
	  -t quay.io/ai-lab/model_servers/object_detection_python:latest . -f base/Containerfile
...
STEP 6/7: EXPOSE 8000
...
Successfully tagged quay.io/ai-lab/model_servers/object_detection_python:latest
bd834bd87c2605cf5e0cc93ee3e4c23c9b7fb030040cea6eb56b0e401efd4e27

Then verified inspecting the image:

podman inspect bd834bd87c2605cf5e0cc93ee3e4c23c9b7fb030040cea6eb56b0e401efd4e27
...
"ExposedPorts": {
    "8000/tcp": {},
    "8080/tcp": {}
},

The new builds produce the following:

$ make PORT=20203 build
...
STEP 2/8: ARG PORT
...
STEP 7/8: EXPOSE $PORT
...
Successfully tagged quay.io/ai-lab/model_servers/object_detection_python:latest
bd834bd87c2605cf5e0cc93ee3e4c23c9b7fb030040cea6eb56b0e401efd4e27
$ podman inspect bd834bd87c2605cf5e0cc93ee3e4c23c9b7fb030040cea6eb56b0e401efd4e27
...
"ExposedPorts": {
    "20203/tcp": {},
    "8080/tcp": {}
},

[Gregory-Pereira]

This one is no better, tests not running. I will close this.