Cannot replace the software source inside docker Ubuntu image

Question

I installed Ubuntu 14.04 image on docker.The image comes with the official software source of Ubuntu.Since I'm in China and can not connect to these servers，I must edit etc/apt/source.list to replace the software source by use vi or vim. However，the Ubuntu image doesn't come with either of the two editors. If I tried to install the editor then i have to change the software source. How can i solve this problem?

Answer 1

You can create a derived docker image as follows:

Dockerfile

FROM ubuntu:14.04
COPY ./sources.list /etc/apt/

sources.list (I used these in China before and they worked well, replace with the ones you prefer)

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to                                                                                                                               
# newer versions of the distribution.
deb http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://cn.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty universe
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://cn.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu trusty partner
# deb-src http://archive.canonical.com/ubuntu trusty partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
#deb http://extras.ubuntu.com/ubuntu trusty main
#deb-src http://extras.ubuntu.com/ubuntu trusty main

After creating these files you can build your image by running for example:

docker build --tag ubuntu:14.04-cn

And use it in your project, if you need to upload it to docker hub you will need to change the name accordingly.

Moreover I suggest you to install the software you need in your image directly so you don't have to install the dependencies each time you start the container, also because in any case you are building your image anyway.