Run a shell script from docker-compose command, inside the container

Question

I am attempting to run a shell script by using docker-compose inside the docker container. I am using the Dockerfile to build the container environment and installing all dependancies. I then copy all the project files to the container. This works well as far as I can determine. (I am still fairly new to docker, docker-compose)

My Dockerfile:

FROM python:3.6-alpine3.7

RUN apk add --no-cache --update \
    python3 python3-dev gcc \
    gfortran musl-dev \
    libffi-dev openssl-dev

RUN pip install --upgrade pip

ENV PYTHONUNBUFFERED 1
ENV APP /app

RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
RUN mkdir $APP
WORKDIR $APP

ADD requirements.txt .
RUN pip install -r requirements.txt

COPY . .

What I am currently attempting is this:

docker-compose file:

version: "2"

services:
  nginx:
    image: nginx:latest
    container_name: nginx
    ports:
      - "8000:8000"
      - "443:443"
    volumes:
      - ./:/app
      - ./config/nginx:/etc/nginx/conf.d
      - ./config/nginx/ssl/certs:/etc/ssl/certs
      - ./config/nginx/ssl/private:/etc/ssl/private
    depends_on:
      - api
  api:
    build: .
    container_name: app
    command: /bin/sh -c "entrypoint.sh"
    expose:
      - "5000"

This results in the container not starting up, and from the log I get the following:

/bin/sh: 1: entrypoint.sh: not found

For more reference and information this is my entrypoint.sh script:

python manage.py db init
python manage.py db migrate --message 'initial database migration'
python manage.py db upgrade
gunicorn -w 1 -b 0.0.0.0:5000 manage:app

Basically, I know I could run the container with only the gunicorn line above in the command line of the dockerfile. But, I am using a sqlite db inside the app container, and really need to run the db commands for the database to initialise/migrate.

Just for reference this is a basic Flask python web app with a nginx reverse proxy using gunicorn.

Any insight will be appreciated. Thanks.

Answer 1

First thing, You are copying entrypoint.sh to $APP which you passed from your build args but you did not mentioned that and second thing you need to set permission for entrypoint.sh . Better to add these three lines so you will not need to add command in docker-compose file.

FROM python:3.6-alpine3.7
RUN apk add --no-cache --update \
    python3 python3-dev gcc \
    gfortran musl-dev \
    libffi-dev openssl-dev
RUN pip install --upgrade pip
ENV PYTHONUNBUFFERED 1
ENV APP /app
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
RUN mkdir $APP
WORKDIR $APP
ADD requirements.txt .
RUN pip install -r requirements.txt

COPY . .
# These line for /entrypoint.sh
COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh
entrypoint "/entrypoint.sh"

docker compose for api will be

  api:
    build: .
    container_name: app
    expose:
      - "5000"

or you can use you own also will work fine

version: "2"

services:
  api:
    build: .
    container_name: app
    command: /bin/sh -c "entrypoint.sh"
    expose:
      - "5000"

Now you can check with docker run command too.

docker run -it --rm myapp

Answer 2

entrypoint.sh needs to be specified with its full path.

It's not clear from your question where exactly you install it; if it's in the current directory, ./entrypoint.sh should work.

(Tangentially, the -c option to sh is superfluous if you want to run a single script file.)