Split neutron server and neutron agent hosts

It is very common usecase when neutron-api is intended to run on
infra hosts (inside lxc containers), while neutron-agents are to run on
independent network nodes.

That was not possible by default, so env.d overrides has to be placed
to fix this behaviour. This patch brings option to do this natively
without extra override.

In the meanwhile it shouldn't break any existing depoyments as leaves
previous groups naming as is.

Change-Id: Ie9fa464561c81b503d6946a7afe4870b92790cee

etc/openstack_deploy/openstack_user_config.yml.example

@@ -422,6 +422,28 @@
 #   infra3:
 #     ip: 172.29.236.103
 #
+# If you want to deploy neutron agents to different set of hosts (net nodes)
+# rather then neutron API, you should define 'network-infra_hosts' and
+# 'network-agent_hosts' instead.
+#
+# Example:
+#
+# network-infra_hosts:
+#   infra1:
+#     ip: 172.29.236.101
+#   infra2:
+#     ip: 172.29.236.102
+#   infra3:
+#     ip: 172.29.236.103
+#
+# network-agent_hosts:
+#   net1:
+#     ip: 172.29.236.201
+#   net2:
+#     ip: 172.29.236.202
+#   net3:
+#     ip: 172.29.236.203
+#
 # --------
 #
 # Level: compute_hosts (optional)

etc/openstack_deploy/openstack_user_config.yml.prod.example

@@ -204,8 +204,8 @@ dashboard_hosts:
   infra3:
     ip: 172.29.236.13
 
-# neutron server, agents (L3, etc)
-network_hosts:
+# neutron api
+network-infra_hosts:
   infra1:
     ip: 172.29.236.11
   infra2:
@@ -213,6 +213,15 @@ network_hosts:
   infra3:
     ip: 172.29.236.13
 
+# neutron agents (L3, DHCP, etc)
+network-agent_hosts:
+  net1:
+    ip: 172.29.236.21
+  net2:
+    ip: 172.29.236.22
+  net3:
+    ip: 172.29.236.23
+
 # ceilometer (telemetry data collection)
 metering-infra_hosts:
   infra1:

inventory/env.d/neutron.yml

@@ -52,6 +52,7 @@ container_skel:
   neutron_agents_container:
     belongs_to:
       - network_containers
+      - network-agent_containers
     contains:
       - neutron_agent
       - neutron_bgp_dragent
@@ -67,6 +68,7 @@ container_skel:
   neutron_server_container:
     belongs_to:
       - network_containers
+      - network-infra_containers
     contains:
       - neutron_server
       - opendaylight
@@ -78,3 +80,15 @@ physical_skel:
   network_hosts:
     belongs_to:
       - hosts
+  network-agent_containers:
+    belongs_to:
+      - all_containers
+  network-agent_hosts:
+    belongs_to:
+      - hosts
+  network-infra_containers:
+    belongs_to:
+      - all_containers
+  network-infra_hosts:
+    belongs_to:
+      - hosts

releasenotes/notes/neutron_agents_split-b3acd7c52d3976df.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    In order to use dedicated net nodes, override of env.d is no longer
+    required.
+    Deployers can set ``network-infra_hosts`` to their infra (LXC) hosts
+    and ``network-agent_hosts`` to their net nodes inside their
+    openstack_user_config.yml or conf.d files.

tests/test_inventory.py

@@ -394,6 +394,10 @@ class TestAnsibleInventoryFormatConstraints(unittest.TestCase):
         'network_all',
         'network_containers',
         'network_hosts',
+        'network-agent_containers',
+        'network-agent_hosts',
+        'network-infra_containers',
+        'network-infra_hosts',
         'neutron_agent',
         'neutron_agents_container',
         'neutron_all',