Apache couldn't determine servername on docker container - apache

Question

I am trying to set up a customized docker container for an existing site. To do so I want to provide my own custom vhost configuration with a ServerName.
But when I try to add a custom vhost configuration and restart apache I get the warning that Apache was unable to determine the global name: Could not reliably determine the server's fully qualified domain name, using 172.26.0.2. Set the 'ServerName' directive globally to suppress this message
What's important is the fact that when I log into container's shell and manually run service apache2 restart I do not get this warning anymore.
How can I suppress that on the build? Should I provide the vhost to the composer somehow else?
Here is my docker-compose.yml is like:
version: '3'
services:
web:
build:
context: ./etc/php
args:
- APP_HOST=${APP_HOST}
ports:
- ${APP_PORT}:80
- ${APP_PORT_SSL}:443
volumes:
- ./var/bin/:/tmp/bin/
- ./app/:/var/www/html/
- ./log/:/var/log/
- ./etc/php/conf/:/usr/local/etc/php/conf.d/
environment:
- VIRTUAL_HOST=${VIRTUAL_HOST}
Then, Dockerfile that adds my own available site:
FROM php:7.0-apache
ENV TERM=xterm
LABEL maintainer="Derek P Sifford <dereksifford#gmail.com>" \
version="0.15.2-php7.0"
ARG APP_HOST
ENV APP_HOST=$APP_HOST
ADD ./sites/app.conf /etc/apache2/sites-available/app.conf
RUN sed -i 's/ServerName APP_HOST/ServerName '$APP_HOST'/g' /etc/apache2/sites-available/app.conf
RUN sed -i 's/AllowOverride None/AllowOverride All/g' /etc/apache2/apache2.conf \
&& a2enmod rewrite expires \
&& a2dissite 000-default.conf \
&& a2ensite app.conf \
&& service apache2 restart
WORKDIR /app
EXPOSE 80 443
And obviously site config:
<VirtualHost *:80>
DocumentRoot "/var/www/html"
ServerName APP_HOST
SetEnv APPLICATION_ENV "development"
<Directory "/var/www/html">
DirectoryIndex index.php
AllowOverride All
Order allow,deny
Allow from all
</Directory>
</VirtualHost>

Answer 1

As indicated here and in the warning message you can set the ServerName property to localhost in /etc/apache2/apache2.conf from within the Dockerfile.

Answer 2

I think there is a problem with your configuration, because you copy it and mount it on a volume. I think your configuration should not evolve when your container is live, so you don't need to mount it.
So, try to remove this line from your docker-compose.yml :
- ./etc/php/conf/:/usr/local/etc/php/conf.d/

Answer 3

On your apache container instance, you should put IP 172.26.0.2 in /etc/hosts and provide a fully qualified name to it e.g.
172.26.0.2 vbox.test.com
Then replace hostname with vbox.test.com
or
put localhost in serverName.
This should help you.