ansible_tower: fix broken import, reuse tower_argument_spec and documentation fragment (#29115)

* module_utils/ansible_tower: fix broken import

* tower_*: use tower_argument_spec & doc fragment

* tower doc fragment: Ansible requires Python 2.6+

* tower_job_wait: fix broken import (Py3 compat)

lib/ansible/modules/web_infrastructure/ansible_tower/tower_project.py

@@ -85,45 +85,7 @@ options:
       required: False
       default: "present"
       choices: ["present", "absent"]
-    tower_host:
-      description:
-        - URL to your Tower instance.
-      required: False
-      default: null
-    tower_username:
-        description:
-          - Username for your Tower instance.
-        required: False
-        default: null
-    tower_password:
-        description:
-          - Password for your Tower instance.
-        required: False
-        default: null
-    tower_verify_ssl:
-        description:
-          - Dis/allow insecure connections to Tower. If C(no), SSL certificates will not be validated.
-            This should only be used on personally controlled sites using self-signed certificates.
-        required: False
-        default: True
-    tower_config_file:
-      description:
-        - Path to the Tower config file. See notes.
-      required: False
-      default: null
-
-
-requirements:
-  - "python >= 2.6"
-  - "ansible-tower-cli >= 3.0.3"
-
-notes:
-  - If no I(config_file) is provided we will attempt to use the tower-cli library
-    defaults to find your Tower host information.
-  - I(config_file) should contain Tower configuration in the following format
-      host=hostname
-      username=username
-      password=password
+extends_documentation_fragment: tower
 '''
 
 
@@ -137,42 +99,36 @@ EXAMPLES = '''
     tower_config_file: "~/tower_cli.cfg"
 '''
 
+from ansible.module_utils.ansible_tower import tower_argument_spec, tower_auth_config, tower_check_mode, HAS_TOWER_CLI
+
 try:
     import tower_cli
     import tower_cli.utils.exceptions as exc
 
     from tower_cli.conf import settings
-    from ansible.module_utils.ansible_tower import tower_auth_config, tower_check_mode
-
-    HAS_TOWER_CLI = True
 except ImportError:
-    HAS_TOWER_CLI = False
+    pass
 
 
 def main():
-    module = AnsibleModule(
-        argument_spec=dict(
-            name=dict(),
-            description=dict(),
-            organization=dict(),
-            scm_type=dict(choices=['manual', 'git', 'hg', 'svn'], default='manual'),
-            scm_url=dict(),
-            scm_branch=dict(),
-            scm_credential=dict(),
-            scm_clean=dict(type='bool', default=False),
-            scm_delete_on_update=dict(type='bool', default=False),
-            scm_update_on_launch=dict(type='bool', default=False),
-            local_path=dict(),
-            tower_host=dict(),
-            tower_username=dict(),
-            tower_password=dict(no_log=True),
-            tower_verify_ssl=dict(type='bool', default=True),
-            tower_config_file=dict(type='path'),
+    argument_spec = tower_argument_spec()
+    argument_spec.update(dict(
+        name=dict(),
+        description=dict(),
+        organization=dict(),
+        scm_type=dict(choices=['manual', 'git', 'hg', 'svn'], default='manual'),
+        scm_url=dict(),
+        scm_branch=dict(),
+        scm_credential=dict(),
+        scm_clean=dict(type='bool', default=False),
+        scm_delete_on_update=dict(type='bool', default=False),
+        scm_update_on_launch=dict(type='bool', default=False),
+        local_path=dict(),
 
-            state=dict(choices=['present', 'absent'], default='present'),
-        ),
-        supports_check_mode=True
-    )
+        state=dict(choices=['present', 'absent'], default='present'),
+    ))
+
+    module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
 
     if not HAS_TOWER_CLI:
         module.fail_json(msg='ansible-tower-cli required for this module')