libcmds: Add support for authentication with gitlab CI

Gitlab CI predefine many variables in its environment, among them the
sever hostname and a token that can be used to authenticate with the
server. If we find these variables in the environment add the
credentials to .netrc which in turn allow git and other tools to
access resources found on the CI server.

Signed-off-by: Alban Bedel <alban.bedel@aerq.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

kas/libcmds.py

@@ -170,7 +170,14 @@ class SetupHome(Command):
         with open(self.tmpdirname + '/.wgetrc', 'w') as fds:
             fds.write('\n')
         with open(self.tmpdirname + '/.netrc', 'w') as fds:
-            fds.write('\n')
+            # Configure the gitlab CI authentification token
+            if os.environ.get('CI_SERVER_HOST', False) \
+                    and os.environ.get('CI_JOB_TOKEN', False):
+                fds.write('machine ' + os.environ['CI_SERVER_HOST'] + '\n'
+                          'login gitlab-ci-token\n'
+                          'password ' + os.environ['CI_JOB_TOKEN'] + '\n')
+            else:
+                fds.write('\n')
         with open(self.tmpdirname + '/.gitconfig', 'w') as fds:
             fds.write('[User]\n'
                       '\temail = kas@example.com\n'