Improve ansible-test completion and messaging.

test/runner/completion/docker.txt

@@ -0,0 +1,9 @@
+centos6
+centos7
+fedora-rawhide
+fedora23
+opensuseleap
+ubuntu1204
+ubuntu1404
+ubuntu1604
+ubuntu1604py3

test/runner/completion/remote.txt

@@ -0,0 +1,3 @@
+freebsd/10.3-STABLE
+freebsd/11.0-STABLE
+osx/10.11

test/runner/completion/windows.txt

@@ -0,0 +1,7 @@
+2008-SP2
+2008-R2_SP1
+2012-RTM
+2012-R2_RTM
+2016-English-Full-Base
+2016-English-Full-Containers
+2016-English-Nano-Base

test/runner/lib/executor.py

@@ -720,7 +720,7 @@ def command_sanity_ansible_doc(args, targets, python_version):
     stdout, stderr = intercept_command(args, cmd, env=env, capture=True, python_version=python_version)
 
     if stderr:
-        # consider any output on stderr an error, even though the return code is zero
+        display.error('Output on stderr from ansible-doc is considered an error.')
         raise SubprocessError(cmd, stderr=stderr)
 
     if stdout:
@@ -924,8 +924,8 @@ def detect_changes_local(args):
 
 def docker_qualify_image(name):
     """
-    :type name: str | None
-    :rtype: str | None
+    :type name: str
+    :rtype: str
     """
     if not name or any((c in name) for c in ('/', ':')):
         return name
@@ -1102,7 +1102,7 @@ def __init__(self, args, command):
         self.remote = args.remote  # type: str
 
         self.docker_privileged = args.docker_privileged if 'docker_privileged' in args else False  # type: bool
-        self.docker_util = docker_qualify_image(args.docker_util if 'docker_util' in args else None)  # type: str | None
+        self.docker_util = docker_qualify_image(args.docker_util if 'docker_util' in args else '')  # type: str
         self.docker_pull = args.docker_pull if 'docker_pull' in args else False  # type: bool
 
         self.tox_sitepackages = args.tox_sitepackages  # type: bool

test/runner/test.py

@@ -205,7 +205,7 @@ def parse_args():
     windows_integration.add_argument('--windows',
                                      metavar='VERSION',
                                      action='append',
-                                     help='windows version')
+                                     help='windows version').completer = complete_windows
 
     units = subparsers.add_parser('units',
                                   parents=[test],
@@ -413,12 +413,12 @@ def add_environments(parser, tox_version=False, tox_only=False):
                               nargs='?',
                               default=None,
                               const='ubuntu1604',
-                              help='run from a docker container')
+                              help='run from a docker container').completer = complete_docker
 
     environments.add_argument('--remote',
                               metavar='PLATFORM',
                               default=None,
-                              help='run from a remote instance')
+                              help='run from a remote instance').completer = complete_remote
 
     remote = parser.add_argument_group(title='remote arguments')
 
@@ -463,5 +463,45 @@ def complete_target(prefix, parsed_args, **_):
     return find_target_completion(parsed_args.targets, prefix)
 
 
+def complete_remote(prefix, parsed_args, **_):
+    """
+    :type prefix: unicode
+    :type parsed_args: any
+    :rtype: list[str]
+    """
+    del parsed_args
+
+    with open('test/runner/completion/remote.txt', 'r') as completion_fd:
+        images = completion_fd.read().splitlines()
+
+    return [i for i in images if i.startswith(prefix)]
+
+
+def complete_docker(prefix, parsed_args, **_):
+    """
+    :type prefix: unicode
+    :type parsed_args: any
+    :rtype: list[str]
+    """
+    del parsed_args
+
+    with open('test/runner/completion/docker.txt', 'r') as completion_fd:
+        images = completion_fd.read().splitlines()
+
+    return [i for i in images if i.startswith(prefix)]
+
+
+def complete_windows(prefix, parsed_args, **_):
+    """
+    :type prefix: unicode
+    :type parsed_args: any
+    :rtype: list[str]
+    """
+    with open('test/runner/completion/windows.txt', 'r') as completion_fd:
+        images = completion_fd.read().splitlines()
+
+    return [i for i in images if i.startswith(prefix) and (not parsed_args.windows or i not in parsed_args.windows)]
+
+
 if __name__ == '__main__':
     main()