Enable proxy settings for docker run

[qiluo-msft]

Signed-off-by: Qi Luo qiluo-msft@users.noreply.github.com

- What I did

- How I did it

- How to verify it

1. docker build
2. docker run -e "http_proxy=ip1" -e "ftp_proxy=ip2" -it
3. start sshd inside container
4. ssh to localhost
5. verify 'env' has these proxy env vars

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

[lguohan]

ENV seems to design for this purpose.

you can use docker run --env = to setup the env.

[qiluo-msft]

I tried ENV in experiments. It works in:

1. docker build time
2. attach to docker container

It doesn't work in: ssh to the daemon process running inside docker

This case is important since Jenkins master will ssh to the slave container and run all the job there.

[lguohan]

${ftp_proxy}

[lguohan]

http_proxy -> https_proxy

[lguohan]

ok