Fix inference-server dockerfile so it can run locally

[toiletpapercode]

@andreaskoepf: #2956 Added an env PROMETHEUS_MULTIPROC_DIR which causes the container to fail to run locally due to the directory not existing.

Creating the directory after settingUSER ${APP_USER} resolves this

[andreaskoepf]

hm. this is treating a symptom ... but why does it happen in the first place? E.g. there must be a problem with the main script then:

Open-Assistant/inference/server/server_main.sh

Lines 7 to 11 in 5ce45f3

	unset PROMETHEUS_MULTIPROC_DIR
	uvicorn main:app --host 0.0.0.0 --port "$PORT"
	else
	if [ -d "${PROMETHEUS_MULTIPROC_DIR}" ]; then rm -rf "${PROMETHEUS_MULTIPROC_DIR}"; fi
	mkdir -p "${PROMETHEUS_MULTIPROC_DIR}"

where I added deletion of the directory or unsetting of the env var?

[andreaskoepf]

@toiletpapercode could you please share the error message that you get?

[toiletpapercode]

@andreaskoepf That server_main.sh is only executed in the FROM base-env as prod block. And that doesn't happen when running locally via docker compose. OnFROM base-env as dev it executes the uvicorn directly.

The error message was a simple directory not found.