docker-compose conflicts with Dokerfile entry-point script - django

Question

I'm trying to create a Docker image with my Django application, but unfortunately I'm getting troubles trying to run my entrypoint script.
Docker exits eith code error 127 and display the following message:
/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
You find below the respective configuration files:
Dockerfile
FROM python:2.7
ENV PYTHONUNBUFFERED 1
RUN mkdir -p /web/src
ADD . /web/src
WORKDIR /web/src
RUN pip install -U pip
RUN pip install -r requirements.txt -U
RUN chmod u+x docker-entrypoint.sh
ENTRYPOINT ["/bin/bash", "docker-entrypoint.sh"]
docker-entrypoint.sh
#!/bin/bash
python manage.py migrate
python manage.py collectstatic --noinput
touch /srv/logs/gunicorn.log
touch /srv/logs/access.log
tail -n 0 -f /srv/logs/*.log &
echo Starting Gunicorn...
exec gunicorn config.wsgi:application \
--name django_server \
--bind 0.0.0.0:8000 \
--workers 3 \
--log-level=info \
--log-file=/srv/logs/gunicorn.log \
--access-logfile=/srv/logs/access.log \
"$#"
docker-compose.yml
version: '2.0'
services:
db:
container_name: db_server
image: postgres
web:
container_name: django_server
build: .
volumes:
- .:/web/src
environment:
- SECRET_KEY=k3jghf1jk%$JH^1GJH5#YUTR#!MBMB<5=7DXXG)JHSX=
- PGDATABASE=postgres
- PGUSER=postgres
- PGPASSWORD=''
- PGHOST=db
- DJANGO_ENV=development
command: python manage.py runserver 0.0.0.0:8000
ports:
- "8000:8000"
links:
- db

Answer 1

After reproducing the problem locally: docker build . build the image successfully, but when trying to start the image using docker-compose up I got the following error exec: gunicorn: not found as the OP mentioned above. Based on this thread I could solve the problem running docker-compose build. So to sum up the 3 following commands should solve the problem:
docker build .
docker-compose build
docker-compose up
Despite this solves the problem for me I'm still confused here, why do I need to run build twice. I mean it should be something wrong somewhere, because as I far as I have understood, docker-compose build should do the same work as docker build ..