tests/vm: send proxy environment variables over ssh

Packages are fetched via proxy that way, if configured on the host.
That might be required to pass firewalls, and it allows to route
package downloads through a caching proxy server.

Needs AcceptEnv setup in sshd_config on the guest side to work.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190617043858.8290-2-kraxel@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

tests/vm/basevm.py

@@ -39,6 +39,13 @@ class BaseVM(object):
     GUEST_PASS = "qemupass"
     ROOT_PASS = "qemupass"
 
+    envvars = [
+        "https_proxy",
+        "http_proxy",
+        "ftp_proxy",
+        "no_proxy",
+    ]
+
     # The script to run in the guest that builds QEMU
     BUILD_SCRIPT = ""
     # The guest name, to be overridden by subclasses
@@ -107,6 +114,8 @@ class BaseVM(object):
                    "-o", "UserKnownHostsFile=" + os.devnull,
                    "-o", "ConnectTimeout=1",
                    "-p", self.ssh_port, "-i", self._ssh_key_file]
+        for var in self.envvars:
+            ssh_cmd += ['-o', "SendEnv=%s" % var ]
         if interactive:
             ssh_cmd += ['-t']
         assert not isinstance(cmd, str)