improve host key checking configurability

see: https://github.com/ansible/tower/issues/3737

awx/main/conf.py

@@ -298,6 +298,16 @@ register(
     category_slug='jobs',
 )
 
+register(
+    'AWX_ISOLATED_HOST_KEY_CHECKING',
+    field_class=fields.BooleanField,
+    label=_('Isolated host key checking'),
+    help_text=_('When set to True, AWX will enforce strict host key checking for communication with isolated nodes.'),
+    category=_('Jobs'),
+    category_slug='jobs',
+    default=False
+)
+
 register(
     'AWX_ISOLATED_KEY_GENERATION',
     field_class=fields.BooleanField,

awx/main/isolated/manager.py

@@ -44,7 +44,7 @@ class IsolatedManager(object):
     def build_runner_params(self, hosts, verbosity=1):
         env = dict(os.environ.items())
         env['ANSIBLE_RETRY_FILES_ENABLED'] = 'False'
-        env['ANSIBLE_HOST_KEY_CHECKING'] = 'False'
+        env['ANSIBLE_HOST_KEY_CHECKING'] = str(settings.AWX_ISOLATED_HOST_KEY_CHECKING)
         env['ANSIBLE_LIBRARY'] = os.path.join(os.path.dirname(awx.__file__), 'plugins', 'isolated')
         set_pythonpath(os.path.join(settings.ANSIBLE_VENV_PATH, 'lib'), env)
 

awx/main/management/commands/test_isolated_connection.py

@@ -33,6 +33,7 @@ class Command(BaseCommand):
             ]):
                 ssh_key = settings.AWX_ISOLATED_PRIVATE_KEY
             env = dict(os.environ.items())
+            env['ANSIBLE_HOST_KEY_CHECKING'] = str(settings.AWX_ISOLATED_HOST_KEY_CHECKING)
             set_pythonpath(os.path.join(settings.ANSIBLE_VENV_PATH, 'lib'), env)
             res = ansible_runner.interface.run(
                 private_data_dir=path,

awx/settings/defaults.py

@@ -403,6 +403,11 @@ EMAIL_HOST_USER = ''
 EMAIL_HOST_PASSWORD = ''
 EMAIL_USE_TLS = False
 
+# Default to skipping isolated host key checking (the initial connection will
+# hang on an interactive "The authenticity of host example.org can't be
+# established" message)
+AWX_ISOLATED_HOST_KEY_CHECKING = False
+
 # The number of seconds to sleep between status checks for jobs running on isolated nodes
 AWX_ISOLATED_CHECK_INTERVAL = 30
 

awx/ui/client/src/configuration/forms/jobs-form/configuration-jobs.form.js

@@ -71,6 +71,9 @@ export default ['i18n', function(i18n) {
                 codeMirror: true,
                 class: 'Form-textAreaLabel Form-formGroup--fullWidth'
             },
+            AWX_ISOLATED_HOST_KEY_CHECKING: {
+                type: 'toggleSwitch',
+            },
             AWX_ISOLATED_CHECK_INTERVAL: {
                 type: 'text',
                 reset: 'AWX_ISOLATED_CHECK_INTERVAL'