docker-standalone

A script for running a standalone docker daemon with a single container

Prerequisites

Docker 1.0.0+ running and using:
- The default native execution driver
- The AUFS storage driver

Usage Examples

$ sudo ./docker-standalone busybox sh -c "while :; do date; sleep 1; done"
Pulling repository busybox
37fca75d01ff: Download complete
a9eb17255234: Download complete
fd5373b3d938: Download complete
d200959a3e91: Download complete
511136ea3c5a: Download complete
42eed7f1bf2a: Download complete
f06b02872d52: Download complete
c120b7cab0b0: Download complete
1f5049b3536e: Download complete
120e218dd395: Download complete
Starting standalone daemon: /var/lib/docker-standalone/479b4956670b8d242a63c86b6f79745c
Started container: busybox sh -c while :; do date; sleep 1; done
^CKilling container
Removing daemon

Modus Operandi

docker-standalone goes through the following step when running a container:

Pull the image using the resident docker daemon
Create a random directory in /var/lib/docker-standalone/
Symlink the container images from the resident docker daemon
Run the container and wait for it to exit
Clean up after container exits or script is terminated

Why?

Docker being a daemon is not always great. Inside docker, there's a minimal non-daemon git-like tool trying to escape. This is a bit of an experiment that realizes this using the docker daemon as-is.

Caveats

There be dragons here.
Currently uses docker0 bridge so container ip address allocation will collide.

TODO

Allocate unique addresses for each standalone container and use docker run --bip.
Allow passing in -p, -e, etc.
Add a --cache argument for specifying a reusable directory for caching pulled container images in order to avoid depending on the resident docker daemon.
Implement the non-daemon mode of operation in docker itself. This might as simple as just combining the daemon and cli modes. I.e., essentially allowing something like docker -d run ....