invalid tar magic with some .tar.gz files about docker-busybox

[jpetazzo]

What error do you see?

Note that you will have other issues: you need a compiler to build make, and the busybox image doesn't have one...

[blankoworld]

Here is the error:

tar: invalid tar magic

On the Internet I see that it could be probably linked to a "OLDGNU compatibility" (or something like that) flag to be activated before busybox compilation.
So I fetch the tar.gz file on a server, extract it, rebuild it, and fetch it on the docker busybox container. I can extract it and go to the second step. And yes, seems that it needs a compiler to build make, so I'm already stucked :(.

My initial need is to have a lightweight docker container that contains lua, lua-filesystem and lua-markdown. This is to avoid to make a 210Mb container for "just" 3 packages…
Seems too complicated for me.

[jpetazzo]

I would suggest to use a basic Debian base image (or another distro if you're more familiar with that).
Yes, the container will be bigger; but on those (e.g.) 210 MB, there will be 200 MB for the base layer, and 10 MB for the LUA layer, so it won't be too much of a big deal.

Unless you have a very specific scenario in mind?

[blankoworld]

I developed a program that uses Lua (lua-filesystem and lua-markdown). To keep the sense of lightweight program I think about lightweight docker container.
I also be interested in busybox as base for many Dockerfile, but as I see it's complex to do so. I first see that someone create a lot of Docker container with some programming language. And when I read the Dockerfile, it just contains "FROM ubuntu" then "RUN apt-get install lua". It's curious for me and think about another way: busybox. But as you said it there is no gcc, GNU make, etc. in busybox which make it difficult to extend a busybox to a light linux core system.

So I follow your advice and use a Debian base image. Docker virtual size show 122Mb.
I'm now inquiring if it would be better to make 2 dockerfile:

• the first one to make a debian + lua inside
• the second one with my program

But that's another problem.

[jpetazzo]

OK. I will close this issue, but don't hesitate to let me know if you have further problems or questions related to the same topic!

[blankoworld]

Ok, thanks for the help ;)

I found this: http://blog.docker.com/2013/06/create-light-weight-docker-containers-buildroot/

If I got bravoure I will test this to have Lua compiled in a buildroot. But only for curiosity ^_^