docker-group-daemonizer

Fast and useful script to daemonize docker groups

Requirements

• Linux 3.10+
• Upstart or systemd (for now, systemd must be activated from the code)
• docker 1.8+
• To build it: Golang, GCC and linux-headers are needed as the Netlink Linux interface is used

Build

go get github.com/mikefaille/docker-group-daemonizer
cd $GOPATH/src/github.com/mikefaille/docker-group-daemonizer
go build .
# docker-group-daemonizer bin is now generated

Usage

Create a Docker group using the following naming scheme : docker-eqX where X is a number between 1 and 100. After exec it : sudo docker-group-daemonizer

Result

Each docker-eqx group having users will obtain dedicated/isolated docker daemon.

To use these daemons with the Docker CLI, we need to specify appropriate DOCKER_HOST env. variable for each user.

DOCKER_HOST must contain docker-eqx socket named /var/run/docker-eqx.sock

Example

$ groups

michael docker-eq1

ls -la /var/run/docker-eq1.sock

srw-rw---- 1 root docker-eq1 0 Sep 3 15:57 /var/run/docker-eq1.sock

export DOCKER_HOST=unix:///var/run/docker-eq1.sock
docker pull busybox
docker images

And, docker info should output something like this :

(...)
## Labels
 [equipe=1]

Troubleshoot

Error no1 :

$ docker pull 
Using default tag: latest
Cannot connect to the Docker daemon. Is 'docker -d' running on this host?

Explanation no1 :

You can connect to the socket unix:///var/run/docker-eq1.sock but the associated daemon is down. Why ? The daemon's bridge could be down or the bridge didn't receive is IP address. You can check if bridge name exist docker-eq1 with is ip using following command to list network interfaces : ip adddr

Fix no1. :

Just recreate bridges named docker-eqx using docker-group-daemonizer.

TODO

(easy to implement) Since docker-group-daemonizer regenerate all bridge named docker-eqx, each execution stop all associated daemon. We must having a way to add only missing bridge. And, --> optionnaly, reset bridge.

(easy to implement) Manually specify only one docker's bridge interface at time corresponding docker-eqx to be added.