How to configure docker container proxy?

You can set the proxy environment variables when starting the container, for example:

docker container run \  -e HTTP_PROXY=http://username:password@proxy2.domain.com \  -e HTTPS_PROXY=http://username:password@proxy2.domain.com \  myimage

If you want the proxy-server to be automatically used when starting a container, you can configure default proxy-servers in the Docker CLI configuration file (~/.docker/config.json). You can find instructions for this in the networking section in the user guide.

For example:

{  "proxies": {    "default": {      "httpProxy": "http://username:password@proxy2.domain.com",      "httpsProxy": "http://username:password@proxy2.domain.com"    }  }}

To verify if the ~/.docker/config.json configuration is working, start a container and print its env:

docker container run --rm busybox envPATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/binHOSTNAME=220e4df13604HTTP_PROXY=http://username:password@proxy2.domain.comhttp_proxy=http://username:password@proxy2.domain.comHTTPS_PROXY=http://username:password@proxy2.domain.comhttps_proxy=http://username:password@proxy2.domain.comHOME=/root

you need instruct the apt script to connect through proxy inside the container

# echo 'Acquire::http::proxy "proxy:port/";' > /etc/apt/apt.conf.d/40proxy

remember, this should be written inside the container

and in the machine that have docker running, the proxy should be configured like people said before in their comments