I'm doing some initial tests with docker. At moment i have my images and I can put some containers running, with:
docker attach container_id
EDIT: I've learned a lot about Docker since originally posting this answer. "Starting services automatically in Docker containers" is not a good usage pattern for Docker. - Instead, use ____ to automatically start Docker containers wherein services run. E.G. fleet or Kubernetes, or even Monit/SystemD/Upstart/Init.d/Cron.
If you are starting the container with the command
/bin/bash, then you can accomplish this in the manner outlined here: http://stackoverflow.com/a/19872810/2971199
So, if you are starting the container with
docker run -i -t IMAGE /bin/bash and if you want to automatically start apache2 when the container is started, edit
/etc/bash.bashrc in the container and add
/usr/local/apache2/bin/apachectl -f /usr/local/apache2/conf/httpd.conf (or whatever your apache2 start command is) to a newline at the end of the file.
Save the changes to your image and restart it with
docker run -i -t IMAGE /bin/bash and you will find apache2 running when you attach.