Docker-compose container exits with status 0 - docker

Question

I am trying to create a docker environment for TYPO3. So far I am creating an application container with apache webserver. But the container always stops with status 0. Is there any tips?
My docker-compose:
version: '3'
services:
app:
build: ./docker/app/
volumes:
- ./app:/app
ports:
- 8080:80
- 8443:443
environment:
- SERVER_NAME=local.typo3.com
db:
image: mysql
build: ./docker/db/
restart: always
ports:
- "3307:3306"
environment:
- MYSQL_ROOT_PASSWORD="root"
- MYSQL_ROOT_USER="root"
The Dockerfile looks like this:
FROM ubuntu:18.04
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update; \
apt-get -y upgrade; \
echo "Europe/Berlin" > /etc/timezone; \
ln -sf /usr/share/zoneinfo/Europe/Berlin /etc/localtime;
#Install apache
RUN apt-get update && \
apt-get -y install apache2;
RUN apt-get update;
#Install php
RUN apt-get -y install php7.2 \
php7.2-soap \
php7.2-mysql \
php7.2-xml \
php7.2-cli \
php7.2-json \
php7.2-ldap \
php-curl;
RUN apt-get install -y --no-install-recommends mysql-client;
COPY resources/000-default.conf /etc/apache2/sites-available/
RUN a2ensite 00-default;
CMD ["service apache2 restart"]
Any help will be appreciated.

Answer 1

As David Maze points out, this simply doesn't work in most containerized environments:
CMD ["service apache2 restart"]
Depending on the environment, this will do one of two things:
It could try to contact systemd, which isn't running because you haven't started it. You don't want to start it! Running a process manager inside a container is generally an anti-pattern.
It would start Apache in the background. When this happens, from Docker's perspective the main process has exited, so the container exits. This is probably what is happening to you.
Rather than using the service command, you should start Apache in the foreground by hand, e.g. by running:
httpd -DFOREGROUND
Or, as suggested, building your application on top of an existing image that already has the necessary features.