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

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

UPDATE:

You have wrong capitalization of environment variables in ENV. Correct one is http_proxy. Your example should be:

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

or

FROM centos ENV http_proxy <HTTP_PROXY> ENV https_proxy <HTTPS_PROXY> RUN yum update  

All variables specified in ENV are prepended to every RUN command. Every RUN command is executed in own container/environment, so it does not inherit variables from previous RUN commands!

Note: There is no need to call docker daemon with proxy for this to work, although if you want to pull images etc. you need to set the proxy for docker deamon too. You can set proxy for daemon in /etc/default/docker in Ubuntu (it does not affect containers setting).

---

Also, this can happen in case you run your proxy on host (i.e. localhost, 127.0.0.1). Localhost on host differ from localhost in container. In such case, you need to use another IP (like 172.17.42.1) to bind your proxy to or if you bind to 0.0.0.0, you can use 172.17.42.1 instead of 127.0.0.1 for connection from container during docker build.

You can also look for an example here: How to rebuild dockerfile quick by using cache?

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 with or without proxy setup.

command docker run option:

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

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 (The official document misses the variable ftpProxy which is useful sometimes)

{  "proxies":  {    "default":    {      "httpProxy": "http://192.168.1.12:3128",      "httpsProxy": "http://192.168.1.12:3128",      "ftpProxy": "http://192.168.1.12:3128",      "noProxy": "*.test.example.com,.example2.com,127.0.0.0/8"    }  } } 

Adjust proxy IP and port for your proxy environment and save to ~/.docker/config.json

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

$ cat Dockerfile  FROM alpine  $ docker build -t demo .       $ docker run -ti --rm demo env|grep -ri proxy (standard input):HTTP_PROXY=http://192.168.1.12:3128 (standard input):http_proxy=http://192.168.1.12:3128 (standard input):HTTPS_PROXY=http://192.168.1.12:3128 (standard input):https_proxy=http://192.168.1.12:3128 (standard input):NO_PROXY=*.test.example.com,.example2.com,127.0.0.0/8 (standard input):no_proxy=*.test.example.com,.example2.com,127.0.0.0/8 (standard input):FTP_PROXY=http://192.168.1.12:3128 (standard input):ftp_proxy=http://192.168.1.12:3128 

Old answer (Decommissioned)

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"