Cannot start apache automatically with docker - apache

Question

I made a simple custom docker setup for php development. So far everything works as expected. The only thing that I cannot figure out is why apache2 does not start automatically.
Here is my dockerfile:
FROM ubuntu:latest
RUN apt-get update && apt-get install -y apache2 php libapache2-mod-php php-mcrypt php-mysql php-cli php-curl php-xml php-intl php-mbstring git vim composer curl
COPY . /var/www/example
COPY vhost.conf /etc/apache2/sites-available/example.conf
RUN a2ensite example
RUN chown -R www-data:www-data /var/www/example/logs
RUN service apache2 restart
And here is my docker-compose.yml:
version: '2'
services:
app:
build:
context: .
dockerfile: Dockerfile
image: myexampleapp
ports:
- 8080:80
tty: true
And here is the output docker-compose up command:
me#mydell:~/workspace/mydockercompose$ docker-compose up -d --build
Creating network "mydockercompose_default" with the default driver
Building app
Step 1/7 : FROM ubuntu:latest
---> f975c5035748
Step 2/7 : RUN apt-get update && apt-get install -y apache2 php libapache2-mod-php php-mcrypt php-mysql php-cli php-curl php-xml php-intl php-mbstring git vim composer curl
---> Using cache
---> 148c3a9d928a
Step 3/7 : COPY . /var/www/example
---> 1fbc1dbacf1e
Step 4/7 : COPY vhost.conf /etc/apache2/sites-available/example.conf
---> 9c08947b09e9
Step 5/7 : RUN a2ensite example
---> Running in 1ef64defe747
Enabling site example.
To activate the new configuration, you need to run:
service apache2 reload
Removing intermediate container 1ef64defe747
---> ca1c8e7e80fc
Step 6/7 : RUN chown -R www-data:www-data /var/www/example/logs
---> Running in 57b0214be7a0
Removing intermediate container 57b0214be7a0
---> b3b270a36bf4
Step 7/7 : RUN service apache2 restart
---> Running in 09d2b1d3bd91
* Restarting Apache httpd web server apache2
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.17.0.2. Set the 'ServerName' directive globally to suppress this message
...done.
Removing intermediate container 09d2b1d3bd91
---> 19fa9a90f9de
Successfully built 19fa9a90f9de
Successfully tagged myexampleapp:latest
Creating mydockercompose_app_1
It shows clearly that apache was restarted successfully. However it actually does not:
me#mydell:~/workspace/mydockercompose$ docker exec -i -t 20add8ad9895 service apache2 status
* apache2 is not running
I am new to docker, so all suggestions (even if they are not answering this specific question) to improve what I am doing so far are welcome.
Thanks

Answer 1

Docker services have to be running in the foreground. In your Dockerfile, RUN service apache2 restart will start apache as background process. Hence the container will exit.
To run apache in the foreground, add the following to the Dockerfile.
CMD ["/usr/sbin/apachectl", "-D", "FOREGROUND"]
FROM ubuntu:latest
RUN apt-get update && apt-get install -y apache2 php libapache2-mod-php php-mcrypt php-mysql php-cli php-curl php-xml php-intl php-mbstring git vim composer curl
COPY . /var/www/example
COPY vhost.conf /etc/apache2/sites-available/example.conf
RUN a2ensite example
RUN chown -R www-data:www-data /var/www/example/logs
CMD ["/usr/sbin/apachectl", "-D", "FOREGROUND"]

Answer 2

The above answer is probably correct that mentioned that you can start it with:
CMD apachectl -D FOREGROUND
With docker it is sometimes a good idea to use the absolute path to a binary. So for example maybe do this instead:
/usr/sbin/apache2 -D FOREGROUND
I had a look a bit on google to see what other people are doing. I found this example of a dockerfile where the guy mentions a script start.sh:
From here: https://github.com/jacksoncage/apache-docker/blob/master/Dockerfile
EXPOSE 80
ADD start.sh /start.sh
RUN chmod 0755 /start.sh
CMD ["bash", "start.sh"]
Here is the start.sh script: https://github.com/jacksoncage/apache-docker/blob/master/start.sh
Which simply just does:
#!/bin/bash
# Start apache
/usr/sbin/apache2 -D FOREGROUND
Unrelated tip:
Your dockerfile you need to pin the version for Ubuntu.
See: https://nickjanetakis.com/blog/docker-tip-18-please-pin-your-docker-image-versions
Let me know if this helps.

Answer 3

If it help you or anybody, i was preparing working example with complete docker-composer:
https://github.com/marekz/docker-composer-example
FROM ubuntu:18.04
EXPOSE 80
ENV TZ=Europe/Warsaw
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
RUN apt-get update
RUN apt-get upgrade -y
RUN apt-get install -y libapache2-mod-php7.2 php7.2 php7.2-cli php7.2-gd php7.2-intl php7.2-mbstring php7.2-mysql php7.2-xml php7.2-xsl php7.2-bcmath php7.2-zip php-apcu npm lynx
RUN apt-get install -y mysql-client composer screen tmux vim nano iputils-ping
ENTRYPOINT service apache2 restart && bash

Answer 4

By analyzing the statements, I found a solution to my error
File: Dockerfile
FROM debian
RUN apt-get update -qq >/dev/null && apt-get install -y -qq procps telnet apache2 php7.3 -qq >/dev/null
RUN useradd --user-group --create-home --shell /bin/false app
RUN mkdir /data && chown -R app /data && chmod 777 /data
COPY php.conf /etc/apache2/mods-available/php7.3.conf
RUN a2enmod userdir && a2enmod php7.3
Error:
To activate the new configuration, you need to run:
service apache2 reload
Solutions:
FROM debian -> FROM debian:10
The reason was some conflict between the debian system and the php version. The latest version of debian has a newer version of PHP (PHP 7.4 at that time).