How do you run `apt-get` in a dockerfile behind a

Question

I am running a virtual machine (Ubuntu 13.10) with docker (version 0.8.1, build a1598d1). I am trying to build an image with a dockerfile. First, I want to update the packages (using the code below - the proxy is obfuscated) but apt-get times out with the error: Could not resolve 'archive.ubuntu.com'.

FROM ubuntu:13.10
ENV HTTP_PROXY <HTTP_PROXY>
ENV HTTPS_PROXY <HTTPS_PROXY>
RUN export http_proxy=$HTTP_PROXY
RUN export https_proxy=$HTTPS_PROXY
RUN apt-get update && apt-get upgrade

I have also run the following in the host system:

sudo HTTP_PROXY=http://<PROXY_DETAILS>/ docker -d &

The host is able to run apt-get without issue.

How can I change the dockerfile to allow it to reach the ubuntu servers from within the container?

Update

I ran the code in CentOS (changing the FROM ubuntu:13.10 to FROM centos) and it worked fine. It seems to be a problem with Ubuntu.

Answer 1

We are doing ...

ENV http_proxy http://9.9.9.9:9999
ENV https_proxy http://9.9.9.9:9999

and at end of dockerfile ...

ENV http_proxy ""
ENV https_proxy ""

This, for now (until docker introduces build env vars), allows the proxy env vars to be used for the build ONLY without exposing them

The alternative to solution is NOT to build your images locally behind a proxy but to let docker build your images for you using docker "automated builds". Since docker is not building the images behind your proxy the problem is solved. An example of an automated build is available at ...

https://github.com/danday74/docker-nginx-lua (GITHUB repo)

https://registry.hub.docker.com/u/danday74/nginx-lua (DOCKER repo which is watching the github repo using an automated build and doing a docker build on a push to the github master branch)

Answer 2

Updated on 02/10/2018

With new feature in docker option --config, you needn't set Proxy in Dockerfile any more. You can have same Dockerfile to be used in and out corporate environment.

--config string      Location of client config files (default "~/.docker/config.json")

or environment variable DOCKER_CONFIG

`DOCKER_CONFIG` The location of your client configuration files.

$ export DOCKER_CONFIG=~/.docker/

https://docs.docker.com/engine/reference/commandline/cli/

https://docs.docker.com/network/proxy/

I recommend to set proxy with httpProxy, httpsProxy, ftpProxy and noProxy.

{
 "proxies":
 {
   "default":
   {
     "httpProxy": "http://127.0.0.1:3001",
     "httpsProxy": "http://127.0.0.1:3001",
     "ftpProxy": "http://127.0.0.1:3001",
     "noProxy": "*.test.example.com,.example2.com"
   }
 }
}

Adjust proxy IP and port if needed and save to ~/.docker/config.json

After yo set properly with it, you can run docker build and docker run as normal.

$ docker build -t demo . 

$ docker run -ti --rm demo env|grep -ri proxy
(standard input):http_proxy=http://127.0.0.1:3001
(standard input):HTTPS_PROXY=http://127.0.0.1:3001
(standard input):https_proxy=http://127.0.0.1:3001
(standard input):NO_PROXY=*.test.example.com,.example2.com
(standard input):no_proxy=*.test.example.com,.example2.com
(standard input):FTP_PROXY=http://127.0.0.1:3001
(standard input):ftp_proxy=http://127.0.0.1:3001
(standard input):HTTP_PROXY=http://127.0.0.1:3001

Old answer

Below setting in Dockerfile works for me. I tested in CoreOS, Vagrant and boot2docker. Suppose the proxy port is 3128

In Centos:

ENV http_proxy=ip:3128 
ENV https_proxy=ip:3128

In Ubuntu:

ENV http_proxy 'http://ip:3128'
ENV https_proxy 'http://ip:3128'

Be careful of the format, some have http in it, some haven't, some with single quota. if the IP address is 192.168.0.193, then the setting will be:

In Centos:

ENV http_proxy=192.168.0.193:3128 
ENV https_proxy=192.168.0.193:3128

In Ubuntu:

ENV http_proxy 'http://192.168.0.193:3128'
ENV https_proxy 'http://192.168.0.193:3128'

If you need set proxy in coreos, for example to pull the image

cat /etc/systemd/system/docker.service.d/http-proxy.conf

[Service]
Environment="HTTP_PROXY=http://192.168.0.193:3128"

Answer 3

and If you want to set proxy for wget you should put these line in your Dockerfile

ENV http_proxy YOUR-PROXY-IP:PORT/
ENV https_proxy YOUR-PROXY-IP:PORT/
ENV all_proxy YOUR-PROXY-IP:PORT/

Answer 4

i had the same problem and found another little workaround: i have a provisioner script that is added form the docker build environment. In the script i set the environment variable dependent on a ping check:

Dockerfile:

ADD script.sh /tmp/script.sh
RUN /tmp/script.sh

script.sh:

if ping -c 1 ix.de ; then
    echo "direct internet doing nothing"
else
    echo "proxy environment detected setting proxy"
    export http_proxy=<proxy address>
fi

this is still somewhat crude but worked for me

Answer 5

As Tim Potter pointed out, setting proxy in dockerfile is horrible. When building the image, you add proxy for your corporate network but you may be deploying in cloud or a DMZ where there is no need for proxy or the proxy server is different.

Also, you cannot share your image with others outside your corporate n/w.

Answer 6

A slight alternative to the answer provided by @Reza Farshi (which works better in my case) is to write the proxy settings out to /etc/apt/apt.conf using echo via the Dockerfile e.g.:

FROM ubuntu:16.04

RUN echo "Acquire::http::proxy \"$HTTP_PROXY\";\nAcquire::https::proxy \"$HTTPS_PROXY\";" > /etc/apt/apt.conf

# Test that we can now retrieve packages via 'apt-get'
RUN apt-get update

The advantage of this approach is that the proxy addresses can be passed in dynamically at image build time, rather than having to copy the settings file over from the host.

e.g.

docker build --build-arg HTTP_PROXY=http://<host>:<port> --build-arg HTTPS_PROXY=http://<host>:<port> .

as per docker build docs.