baseimage-docker

# A minimal Ubuntu base image modified for Docker-friendliness

[![Release](https://github.com/phusion/baseimage-docker/actions/workflows/main.yml/badge.svg)](https://github.com/phusion/baseimage-docker/actions/workflows/main.yml)

_Baseimage-docker only consumes 8.3 MB RAM and is much more powerful than Busybox or Alpine. See why below._

Baseimage-docker is a special [Docker](https://www.docker.com) image that is configured for correct use within Docker containers. It is Ubuntu, plus:

 * Modifications for Docker-friendliness.
 * Administration tools that are especially useful in the context of Docker.
 * Mechanisms for easily running multiple processes, [without violating the Docker philosophy](#docker_single_process).

You can use it as a base for your own Docker images.

Baseimage-docker is available for pulling from [the Docker registry](https://hub.docker.com/r/phusion/baseimage) and [GHCR (GitHub Container Registry)](https://github.com/phusion/baseimage-docker/pkgs/container/baseimage)!

### What are the problems with the stock Ubuntu base image?

Ubuntu is not designed to be run inside Docker. Its init system, Upstart, assumes that it's running on either real hardware or virtualized hardware, but not inside a Docker container. But inside a container you don't want a full system; you want a minimal system.  Configuring that minimal system for use within a container has many strange corner cases that are hard to get right if you are not intimately familiar with the Unix system model. This can cause a lot of strange problems.

Baseimage-docker gets everything right. The "Contents" section describes all the things that it modifies.

<a name="why_use"></a>
### Why use baseimage-docker?

You can configure the stock `ubuntu` image yourself from your Dockerfile, so why bother using baseimage-docker?

 * Configuring the base system for Docker-friendliness is no easy task. As stated before, there are many corner cases. By the time that you've gotten all that right, you've reinvented baseimage-docker. Using baseimage-docker will save you from this effort.
 * It reduces the time needed to write a correct Dockerfile. You won't have to worry about the base system and you can focus on the stack and the app.
 * It reduces the time needed to run `docker build`, allowing you to iterate your Dockerfile more quickly.
 * It reduces download time during redeploys. Docker only needs to download the base image once: during the first deploy. On every subsequent deploys, only the changes you make on top of the base image are downloaded.

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**Related resources**:
  [Website](http://phusion.github.io/baseimage-docker/) |
  [Github](https://github.com/phusion/baseimage-docker) |
  [Docker registry](https://registry.hub.docker.com/r/phusion/baseimage/) |
  [Discussion forum](https://groups.google.com/d/forum/passenger-docker) |
  [Twitter](https://twitter.com/phusion_nl) |
  [Blog](http://blog.phusion.nl/)

**Table of contents