Cannot get virtual host to work in docker apache container

Docker Hub
1

Hoping someone can advise… I have been trying to create a simple apache container that configures a virtual host in apache then displays its custom index.html. Outside of docker, this works fine, but when I attempt to replicate such config in a Dockerfile, it either fails with ‘can’t locate apache2’ error if I try a ubuntu base image or it just displays the default ‘It works!’ index.html if I try the httpd 2.4 base image. My latest attempt at Dockerfile is as follows:

FROM httpd:2.4
LABEL maintainer="someemail@gmail.com"
CMD mkdir /var/www/html/tutorial_docker/
COPY ./index.html /var/www/html/tutorial_docker/
COPY ./tutorialDocker.conf /etc/apache2/sites-available/
EXPOSE 80

Thanks if someone could advise?

3

Hello and welcome,

could you please provide the content of tutorialDocker.conf and the way you’ve started the container?

As apache is not part of the default-ubuntu-image the mentioned error-message is normal - you have to install it using apt-get update && apt-get install apache2 or use an image which is specialized for providing the apache-service (as you did using the httpd-image).
I would prefer the way using the httpd-image as it should be smaller and provide less additional and not needed software (which is good for security-reason).

Best regards
Matthias

4

Hi thanks

Well for what it’s worth, the tutorialDocker.conf is as follows:

<VirtualHost *:80>
	ServerAdmin admin@example.com
	ServerName example.com
	ServerAlias www.example.com
	DocumentRoot /var/www/html/tutorial_docker
	ErrorLog ${APACHE_LOG_DIR}/error.log
	CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

And the command to run the new docker image was as follows:

sudo docker run -d -p 9090:80 --name webserver tutorial_docker:1.0

However to your point, and after following the httpd base docker image documentation, I was able to get it to work rather aimply, i.e.

FROM httpd:2.4
COPY ./src_files/index.html /usr/local/apache2/htdocs/

Thanks for your help!

5

TLDR; config-file was placed at wrong location, was not loaded and configuration for document-root was missing

Hello,

I’m sorry for the bad experience you received from the tutorial (which tutorial?) - but with the unmodified Dockerfile and .conf-file it would not work.

I did some tests and modified the Dockerfile to

FROM httpd:2.4
LABEL maintainer="someemail@gmail.com"
RUN mkdir -p /var/www/html/tutorial_docker/ && sed -i -E 's:^#(Include conf/extra/httpd-default.conf):\1:' /usr/local/apache2/conf/httpd.conf
COPY ./index.html /var/www/html/tutorial_docker/
COPY ./tutorialDocker.conf /usr/local/apache2/conf/extra/httpd-default.conf
EXPOSE 80

to place your tutorialDocker.conf within the image as /usr/local/apache2/conf/extra/httpd-default.conf and to load it by modifying the /usr/local/apache2/conf/httpd.conf.

And I’ve modified the tutorialDocker.conf to

<Directory "/var/www/html/tutorial_docker">
  Options Indexes FollowSymLinks
  AllowOverride All
  Require all granted
</Directory>

<VirtualHost *:80>
  ServerAdmin admin@example.com
  ServerName example.com
  ServerAlias www.example.com
  DocumentRoot /var/www/html/tutorial_docker
  ErrorLog /proc/self/fd/2
  CustomLog /proc/self/fd/1 combined
</VirtualHost>

to send the log-information to the place where you can get them with docker logs webserver and to specify some settings about the directory you have specified as DocumentRoot. Without the <Directory ... apache will return a 403 - Forbidden.

Best regards
Matthias

6

Hi Matthias thanks for taking such effort to elaborate on my question. It’s greatly appreciated.

I just called this my own personal docker tutorial, I’d previously followed some tutorial on how to stand up a simple website in Apache and figured this could be replicated in docker. Seems however, I was not aware of the nuances of such a task.

I tried building your script but unfortunately it failed with the following error:

sed: -e expression #1, char 47: invalid reference \1 on `s’ command’s RHS

against the following line:

RUN mkdir -p /var/www/html/tutorial_docker/ && sed -i 's:^#(Include conf/extra/httpd-default.conf):\1:' /usr/local/apache2/conf/httpd.conf

Sounds like something rather trivial but I know about sed even less than I know docker :expressionless:

7

I’m sorry for this error. I forgot the -E-parameter for sed. Without this parameter the regular expressions and grouping will not work. The answer above is now updated.

8

Thanks again Matthias.

I’ve reviewed your fine work and believe I now understand how you scripted the Dockerfile. Basically you utilised stream editor linux command to find a string in httpd.conf so as to be able to uncomment / include httpd-default.conf in this Apache implementation. You then overwrite httpd-default.conf 's contents with tutorialDocker.conf, which you had previously defined to properly enable my virtual host as well as enable its logging for the docker logs [container name] command.

This has been a constructive exercise and I appreciate your time. Thanks heaps!