Configuration outbound proxy

Installation
4

We have no user and password, output from set | grep -i proxy

HTTPS_PROXY=http://<server>:<port>/
HTTP_PROXY=http://<server>:<port>/
NO_PROXY='127.0.0.1, localhost, <internal-network>'
http_proxy=http://<server>:<port>/
https_proxy=http://<server>:<port>/
no_proxy='127.0.0.1, localhost, <internal-network>'

A curl from within the container, which uses the proxy-settings:
curl -o /dev/null -v https://avatars.discourse.org/v2/letter/s/5f9b8f/45.png
results in: 200 OK