Docker

This page is an updated version of the original Docker builds announcement

Docker builds

These are TurnKey builds optimized to run as docker containers, supporting automatic download via the docker public index.

All TurnKey appliances are available on the Docker Hub (generously provided by Docker, Inc), which streamlines deployment. For example:

docker pull turnkeylinux/core-14.2
docker run -i -t -d turnkeylinux/core-14.2

Docker containers can be run in the foreground or the background, so we've tried our best to support all use cases with regards to initialization (aka. inithooks) - secret regeneration, setting of passwords, application configuration, etc. 

Depending on your use case, we recommend two options:

Option 1: Initialization via ssh (interactive)

On first login, you will be prompted to initialize the appliance.

CID=$(docker run -i -t -d turnkeylinux/core-14.2)
CIP=$(docker inspect --format='{{.NetworkSettings.IPAddress}}' $CID)
docker logs $CID | grep "Random initial root password"
ssh root@$CIP

Option 2: Create new image with preseeded values (non-interactive)

The appliance will initialize itself with the provided configuration.  Once initialized, the configuration will be deleted. For more information see inithooks.

mkdir /root/wordpress

cat > /root/wordpress/inithooks.conf <<EOF
export ROOT_PASS=secretrootpass
export DB_PASS=secretmysqlpass
export APP_PASS=secretadminwppass
export APP_EMAIL=admin@example.com
export APP_DOMAIN=www.example.com
export HUB_APIKEY=SKIP
export SEC_UPDATES=FORCE
EOF

cat > /root/wordpress/Dockerfile <<EOF
FROM turnkeylinux/wordpress-14.2
ADD inithooks.conf /etc/inithooks.conf
EOF

docker build -t wordpress-14.2 /root/wordpress
docker run -i -t -d wordpress-14.2

Notes

Pre-configured run command

Docker is designed for "application or process" containers - for example, running mysql, and only mysql. Docker short-circuits /sbin/init so you can't really "boot" a container like in vanilla LXC.

To work around this, we've included /usr/sbin/start.sh (default run command) which will start all services and drop to a shell. When the shell is exited, the services will be stopped. For this reason, SSH is recommended for regular console usage.

STDIN and TTY options required

The -i and -t options are required to attach STDIN and allocate a TTY to the container. There have been moves by Docker to allow this to be pre-configured but we haven't yet looked deeper into that and are not up to date on hte current state of play.

Pre-configured to expose ports

All TurnKey Docker appliances are configured to expose their custom services. This means that the host can access the services, but they are not exposed to the network.

Exposing ports to the network needs to be done at runtime (docs), for example:

# bind port 80 on the host to the container's port 80
docker run -i -t -d -p 80:80 turnkeylinux/lamp-14.2

Or to use an alternate host port:

# bind port 8080 on the host to the container's port 80
docker run -i -t -d -p 0.0.0.0:8080:80 turnkeylinux/lamp-14.2

Skipping security updates on first boot

During development I added support to start.sh to override the default SEC_UPDATES value to speed up my testing. I was going to remove this support or leave it undocumented, but decided others might find it useful when testing (and only in testing).

# THIS IS NOT RECOMMENDED, USE AT YOUR OWN RISK!
docker run -i -t -d -e SEC_UPDATES=SKIP turnkeylinux/openldap-14.2