Add env command to ansible-test and run in CI. (#50176)

* Add `env` command to ansible-test and run in CI.
* Avoid unnecessary docker pull.

test/runner/lib/cli.py

@@ -43,6 +43,11 @@ from lib.config import (
     ShellConfig,
 )
 
+from lib.env import (
+    EnvConfig,
+    command_env,
+)
+
 from lib.sanity import (
     command_sanity,
     sanity_init,
@@ -483,6 +488,21 @@ def parse_args():
 
     add_extra_coverage_options(coverage_xml)
 
+    env = subparsers.add_parser('env',
+                                parents=[common],
+                                help='show information about the test environment')
+
+    env.set_defaults(func=command_env,
+                     config=EnvConfig)
+
+    env.add_argument('--show',
+                     action='store_true',
+                     help='show environment on stdout')
+
+    env.add_argument('--dump',
+                     action='store_true',
+                     help='dump environment to disk')
+
     if argcomplete:
         argcomplete.autocomplete(parser, always_complete_options=False, validator=lambda i, k: True)