Gitosis in Docker

If you have a legacy gitosis install going that is becoming harder and harder to maintain, this is for you. This runs gitosis in a container that you can map to a legacy gitosis directory.

Build

# Copy your public ssh key to the current directory
cp ~/.ssh/id_rsa.pub .

# On each build, the container will generate a new ssh key, which means you'll
# get an ssh warning each time. To avoid it, the build process will copy
# ssh_host_* to the container's /etc/ssh/ ; we need to put them here first.
sudo cp /etc/ssh/ssh_host_* .
sudo chown `id -un`:`id -gn` ssh_host_*

# In the below command, set USER to either gitosis or git,
# depending on whether you want to clone is git@ or gitosis@
# The default is gitosis.

# Also, we set HOST_UID and HOST_GID to make sure that both the host
# and the container have the same uid/gid for user gitosis; otherwise
# the docker container cannot read/write the mapped directory
docker build --build-arg USER=gitosis --build-arg HOST_UID=`id -u gitosis` --build-arg HOST_GID=`id -g gitosis`  -t gitosis .

# You should remove the ssh keys when you're done
rm ./ssh_host_*

Run

# Your public IP, try to guess it from eth0
IP=`ip a s eth0 | egrep -o 'inet [0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | cut -d' ' -f2 | head -1`

# Public port where you want gitosis to be available
PORT=8222

# runs the gitosis image, while mounting the legacy /srv/gitosis directory and makes it accessible
docker run --mount type=bind,source=/srv/gitosis,target=/srv/gitosis -p $IP:$PORT:22 -it gitosis:latest

# is now accessible... assumes USER was set to gitosis earlier; otherwise use git@
git clone gitosis@${IP}:${PORT}/gitosis-admin

Run in the background

docker run -d --mount type=bind,source=/srv/gitosis,target=/srv/gitosis -p ${IP}:${PORT}:22 gitosis:latest

Modify .ssh/config

You'll likely need something like this in your ~/.ssh/config

Host git.yourserver.com
  User gitosis # ...or git if that's what you used earlier
  Port 8222 # or whatever port you are making available