Add peers readonly api and instancelink constraint (#13916)

Add Disconnected link state

introspect_receptor_connections is a periodic
task that examines active receptor connections
and cross-checks it with the InstanceLink info.

Any links that should be active but are not
will be put into a Disconnected state. If
active, it will be in an Established state.

UI - Add hop creation and peers mgmt (#13922)

* add UI for mgmt peers, instance edit and add

* add peer info on detail and bug fix on detail

* remove unused chip and change peer label

* rename lookup, put Instance type disable on edit

---------

Co-authored-by: tanganellilore <lorenzo.tanagnelli@hotmail.it>

awx/api/urls/peers.py

@@ -0,0 +1,14 @@
+# Copyright (c) 2017 Ansible, Inc.
+# All Rights Reserved.
+
+from django.urls import re_path
+
+from awx.api.views import PeersList, PeersDetail
+
+
+urls = [
+    re_path(r'^$', PeersList.as_view(), name='peers_list'),
+    re_path(r'^(?P<pk>[0-9]+)/$', PeersDetail.as_view(), name='peers_detail'),
+]
+
+__all__ = ['urls']

awx/api/urls/urls.py

@@ -84,6 +84,7 @@ from .oauth2_root import urls as oauth2_root_urls
 from .workflow_approval_template import urls as workflow_approval_template_urls
 from .workflow_approval import urls as workflow_approval_urls
 from .analytics import urls as analytics_urls
+from .peers import urls as peers_urls
 
 v2_urls = [
     re_path(r'^$', ApiV2RootView.as_view(), name='api_v2_root_view'),
@@ -153,6 +154,7 @@ v2_urls = [
     re_path(r'^bulk/$', BulkView.as_view(), name='bulk'),
     re_path(r'^bulk/host_create/$', BulkHostCreateView.as_view(), name='bulk_host_create'),
     re_path(r'^bulk/job_launch/$', BulkJobLaunchView.as_view(), name='bulk_job_launch'),
+    re_path(r'^peers/', include(peers_urls)),
 ]