Docker

My little page about getting docker to run, done by somebody having no idea what docker is.

Yeah, DAU-docker!

First install docker

• sudo apt-get install docker.io
• sudo usermod -a -G docker $(id -un)
• # logoout/login to get your group attribution

Learn something about the docker philosophy

You usually never log in to the container but specify all settings in the Dockerfile. Recreating the container should give you a ready to run application.

Most installs don't care really what happens to your data, but docker has a feature for this. Put the data into a separate container than the application. Then make the data container mount points visible in your application container. This way you can replace the application (update) without needing a backup/restore step.

Mediawiki

Fist some settings

• WEBPORT=8080 # on which port the webserver should listen on the main host, if you have already a webserver, 80 won't work
• DBPASSWORD="$(openssl rand -base64 9)" # the password for the database (humm... save it :-)
• DOCKERNAME="mediawiki"

Create a database

• # inspired from https://hub.docker.com/_/mysql/
• # Create a data container with a directory /var/lib/mysql
• docker create -v /var/lib/mysql --name wiki-mysql-data mysql:latest /bin/true
• docker run --name wiki-mysql --volumes-from wiki-mysql-data -e MYSQL_ROOT_PASSWORD=$DBPASSWORD -d mysql:latest
• docker ps -a | grep wiki-mysql.* # look the nice containers we just did

Create a mediawiki

well probably something like found here https://hub.docker.com/r/nickstenning/mediawiki/ (with data container support) as stated on that webpage:

• docker run --name $DOCKERNAME --link wiki-mysql:mysql -p $WEBPORT:80 -d nickstenning/mediawiki

Configure mediawiki

• echo "connect to http://localhost:$WEBPORT/"
• click on "setup the wiki"
  • database host: mysql
  • database name: mysql
  • table prefix: mw #change this if you install more than one mediawiki into this database
  • username: root
  • echo password: $DBPASSWORD
  • at end of setup you get a LocalSettings.php to download
  • this file has to be provided to the docker or put into the container. Seems to be several ways to do it.
• docker stop $DOCKERNAME # stop the container as we want to mount data...
• docker rm $DOCKERNAME # I have no idea how to add parameters, so I just start from zero

Create wiki data container

• docker create --name ${DOCKERNAME}-data -v /data nickstenning/mediawiki /bin/true
• docker run --name ${DOCKERNAME} --volumes-from ${DOCKERNAME}-data --link wiki-mysql:mysql -p $WEBPORT:80 -d nickstenning/mediawiki
• cat LocalSettings.php | docker exec -i ${DOCKERNAME} sh -c 'cat > /data/LocalSettings.php'
• docker exec -i ${DOCKERNAME} chown www-data:www-data /data/LocalSettings.php
• docker exec -i ${DOCKERNAME} chmod 444 /data/LocalSettings.php

• echo "wiki is on http://localhost:$WEBPORT/index.php"

More help: well the usual mediawiki help

Engelsystem

This does not use a data container, but as it's often only for a short event, I don't care.

Give some configuration stuff

• ENGELPORT=80 # on which port the engel system should listen on the main host, if you have a webserver, 80 won't work
• ENGELDB=3306 # on which port the mysql of the engelsystem should be visible on the main host
• DBPASSWORD="$(openssl rand -base64 9)" # the password for the database (humm... save it it :-)
• ENGELPASSWORD="$(openssl rand -base64 9)" # the password for the engelsystem (humm... save it it :-)
• DOCKERNAME="engelsystem"
• ENGELADMIN="engeladmin" # well just use it

from https://github.com/ruep/dockerfile-engel

• git clone https://github.com/ruep/dockerfile-engel.git
• cd dockerfile-engel/
• docker build -t engelweb-app . # this takes a long time
• docker run --name "$DOCKERNAME" -d -p ${ENGELPORT}:80 -p ${ENGELDB}:3306 -e MYSQL_PASS="$DBPASSWORD" engelweb-app
• docker exec -t "$DOCKERNAME" sed -i 's/-pengel/-p'$DBPASSWORD'/' /engelweb/db/createdb.sh # needed coz db pass hardcoded
• docker exec -t "$DOCKERNAME" /engelweb/db/createdb.sh engelsystem engeladmin "$ENGELPASSWORD"
• docker exec -t "$DOCKERNAME" sh -c "/usr/bin/mysql -uadmin -p$DBPASSWORD engelsystem < /engelweb/db/install.sql"
• docker exec -t "$DOCKERNAME" sh -c "/usr/bin/mysql -uadmin -p$DBPASSWORD engelsystem < /engelweb/db/update.sql"

• echo "Please remember the database password: $DBPASSWORD"
• echo "Please remember the engelsystem login: ${ENGELADMIN} ${ENGELPASSWORD}"
• echo login to http://localhost:$ENGELPORT/ with user 'admin' and password 'asdfasdf'