TestCliProxyDisableProxyUnixSock runs `docker info` by
clearing env however if the daemon is set up to run in a
different machine (e.g. Windows CI case) it does not make
use of DOCKER_TEST_HOST and tries to connect unix sock.
This fix injects DOCKER_HOST back to the test.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
Makes sure the CLI does not use HTTP_PROXY when connecting to unix
socket.
Also adds some tests to make sure this functionality works as expected.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>