Can I install the 12.04 distribution in a docker container hosted by a 16.04 distribution

Question

I have a docker container hosted by 16.04 can I install a 12.04 distribution into this container?

Solution

There is no need to install the image from scratch, I found this answer where you can make docker to download the desired version and I adapted to my needs:

sudo docker run ubuntu:12.04 cat /etc/issue

returns this:

Unable to find image 'ubuntu:12.04' locally
12.04: Pulling from library/ubuntu
Downloading
...
Status: Downloaded newer image for ubuntu:12.04
Ubuntu 12.04.4 LTS \n \l

or alternatively you can use:

sudo docker pull ubuntu:12.04

and then run that image with

sudo docker run -i -t ubuntu:12.04 /bin/bash

to make sure in the prompt try to see the version:

cat /etc/issue

PS. Dont forget to commit the changes, before exiting, otherwise are lost. First get the container id using this command:

sudo docker ps -l

Commit changes to the container:

sudo docker commit <container_id> repo/img1 

Then run the container:

sudo docker run -i -t repo/img1 /bin/bash