A minimal Docker base image with a correct and usable system

Baseimage-docker is a Docker image meant to serve as a good base for any other Docker container. It contains a minimal base system with the most important things already installed and set up correctly.

Included in the image are:

Component	Why is it included? / Remarks	Remarks
Ubuntu 12.04 LTS	The base system.
syslog-ng	A syslog daemon is necessary so that many services - including the kernel itself - can correctly log to /var/log/syslog. If no syslog daemon is running, a lot of important messages are silently swallowed. Only listens locally.	Only listens locally.
ssh server
runit	For service supervision and management. Much easier to use than SysV init and supports restarting daemons when they crash. Much easier to use and more lightweight than Upstart.

• The SSH server, so that you can easily login to your container to inspect or administer things.
  • Password and challenge-response authentication are disabled by default. Only key authentication is allowed.
  • It allows an predefined key by default to make debugging easy. You should replace this ASAP. See instructions.

Why use baseimage-docker instead of doing everything yourself in Dockerfile?

# Use phusion/baseimage as base image. To make your builds reproducible, make
# sure you lock down to a specific version, not to `latest`!
FROM phusion/baseimage:<VERSION>

# Remove authentication rights for insecure_key.
RUN rm -f /root/.ssh/authorized_keys /home/*/.ssh/authorized_keys

# Use baseimage-docker's init process.
CMD ["/sbin/my_init"]

# ...put other build instructions here...

# Clean up APT when done.
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*