Supervisord exits inside Docker container when run with docker-compose 'command:', but not when its run from bash

Question

I'm trying to run DjangoRQ workers inside a docker container - a simple 'worker' container which I will run on a digital ocean droplet. I'm using supervisord to run multiple workers.

Supervisord will run if I set the container command to sleep 3600 (so I can bash in before it crashes) then bash into the container and run supervisord -c supervisord.conf . However, if I set the command on the container to that very same command, command: supervisord -c supervisord.conf then the container exits saying Unlinking stale socket /tmp/supervisor.sock

 worker:
    build:
      context: ./
      dockerfile: DockerfileWorker
    env_file:
      - .env
    environment:
      - DJANGO_CONFIG
    volumes:
      - .:/dask 
    depends_on:
      - postgres
      - redis
    command: sleep 3600

# `python-base` sets up all our shared environment variables
FROM ubuntu:latest

    # python
ENV PYTHONUNBUFFERED=1 \
    # prevents python creating .pyc files
    PYTHONDONTWRITEBYTECODE=1 \
    \
    # pip
    PIP_NO_CACHE_DIR=off \
    PIP_DISABLE_PIP_VERSION_CHECK=on \
    PIP_DEFAULT_TIMEOUT=100 \
    \
    # poetry
    # https://python-poetry.org/docs/configuration/#using-environment-variables
    POETRY_VERSION=1.1.5 \
    # make poetry install to this location
    POETRY_HOME="/opt/poetry" \
    # make poetry create the virtual environment in the project's root
    # it gets named `.venv`
    POETRY_VIRTUALENVS_IN_PROJECT=true \
    # do not ask any interactive question
    POETRY_NO_INTERACTION=1 \
    \
    # paths
    # this is where our requirements + virtual environment will live
    PYSETUP_PATH="/opt/pysetup" \
    VENV_PATH="/opt/pysetup/.venv" \
    LOG_LEVEL=DEBUG


# prepend poetry and venv to path
ENV PATH="$POETRY_HOME/bin:$VENV_PATH/bin:$PATH"

RUN apt-get update \
    && apt-get install --no-install-recommends -y \
        # deps for installing poetry
        curl \
        # deps for building python deps
        build-essential \
        python3-pip

# install poetry - respects $POETRY_VERSION & $POETRY_HOME
RUN pip3 install poetry

# copy project requirement files here to ensure they will be cached.
WORKDIR $PYSETUP_PATH
COPY poetry.lock pyproject.toml ./

# install runtime deps - uses $POETRY_VIRTUALENVS_IN_PROJECT internally
RUN poetry install --no-dev

# # `production` image used for runtime
# FROM python-base as production
COPY . /dask
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
WORKDIR /dask

Answer 1

For anyone who hit this problem - the solution is frustratingly simple. You must run supervisord in the foreground or Docker doesn't think a process is running so it exits. Add the -n tag to supervisord and you'll be good to go.

worker:
    build:
      context: ./
      dockerfile: DockerfileWorker
    env_file:
      - .env
    environment:
      - DJANGO_CONFIG
    volumes:
      - .:/dask 
    depends_on:
      - postgres
      - redis
     command: supervisord -n -c supervisord.conf