Docker Images Are Moving From Ubuntu To Alpine Linux

[Cyberax]

Alpine is super-great as a platform to build fully static binaries. You can use its packages and then just link everything into one big image that can be run on _any_ Linux with a recent enough kernel. I can see why Docker would want to use it.

Oh, and Alpine can be used with systemd just fine.

[jaxxed]

Why not systemd? It would support more dynamic things and cgroups. Also GNU libc is more battle tested and better license than musl's incompatible BSD. /ducks

the most common best-practice for docker containers is to run single service processes at run-time, so systemd was mainly out of scope. Systemd is starting to show up for some container approaches.

[rabcor]

It's not that I don't like the alpine linux idea, it's just that I don't like their (insanely) lacking package repositories that didn't even have a proper Wireless Internet Management GUI last time I checked (I seriously had to script it myself with the help of zenity...)

[caligula]

Alpine is super-great as a platform to build fully static binaries. You can use its packages and then just link everything into one big image that can be run on _any_ Linux with a recent enough kernel. I can see why Docker would want to use it.

Oh, and Alpine can be used with systemd just fine.

I'm just a bit curious. Does systemd run on musl systems or does it need glibc? If you need both, sounds a bit bloated if you're also wanting to use alpine as a build system.

[Modu]

Popular official Docker images are all based on debian:jessie not ubuntu.

[Cyberax]

I'm just a bit curious. Does systemd run on musl systems or does it need glibc? If you need both, sounds a bit bloated if you're also wanting to use alpine as a build system.

There's a patchset that allows systemd to be used with musl. It's fairly trivial and only needs a couple of non-trivial functions implemented.

[chrisb]

the most common best-practice for docker containers is to run single service processes at run-time, so systemd was mainly out of scope. Systemd is starting to show up for some container approaches.

But without PID 1 you end up with problems like "Docker and the PID 1 zombie reaping problem"

Docker looks like a temporary solution for single service processes, one that will become far less popular once Linux has a standardised app container framework.

[Bestia]

Popular official Docker images are all based on debian:jessie not ubuntu.

There are official Docker images based on Debian but they are nowhere near in terms of the popularity compared to official Docker images based on Ubuntu.

https://hub.docker.com/explore/

1. busybox 64.8 millions pulls
2. ubuntu 40.1 millions pulls
...
10. debian 6.6 millions pulls

[chithanh]

There's a patchset that allows systemd to be used with musl. It's fairly trivial and only needs a couple of non-trivial functions implemented.

I think the patchset was rejected by systemd upstream and thus people stopped bothering

[Modu]

There are official Docker images based on Debian but they are nowhere near in terms of the popularity compared to official Docker images based on Ubuntu.

https://hub.docker.com/explore/

1. busybox 64.8 millions pulls
2. ubuntu 40.1 millions pulls
...
10. debian 6.6 millions pulls

It's expected that people who are not satisfied with the official application images build their own custom images based on busybox or ubuntu rather than default base debian. Please take a closer look at the top ten applicaion images' Dockerfile and see that they are all based on distro image debian. Recently, some official docker images actually moved from being based on ubuntu to debian. The article and its title is simply wrong about the default base image.