Update defaults for clusterNetworkCIDR & hostSubnetLength

Per https://github.com/openshift/openshift-docs/issues/1700:

The default values for pod networking have changed:
    - clusterNetworkCIDR now defaults to 10.128.0.0/14 (10.128.0.0 - 10.131.255.255)
      rather than 10.1.0.0/16.
    - hostSubnetLength now defaults to 9 rather than 8
      (meaning each node will be assigned a /23 subnet rather than a /24)

Fixes Bug 1320952

3 files changed, 27 insertions, 13 deletions

diff --git a/inventory/byo/hosts.origin.example b/inventory/byo/hosts.origin.example
index 13f4c214c..e769537f9 100644
--- a/inventory/byo/hosts.origin.example
+++ b/inventory/byo/hosts.origin.example
@@ -472,7 +472,7 @@ openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true',
 # network blocks should be private and should not conflict with network blocks
 # in your infrastructure that pods may require access to. Can not be changed
 # after deployment.
-#osm_cluster_network_cidr=10.1.0.0/16
+#osm_cluster_network_cidr=10.128.0.0/14
 #openshift_portal_net=172.30.0.0/16
 
 
@@ -492,9 +492,9 @@ openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true',
 # the CIDRs reserved for external IPs, nodes, pods, or services.
 #openshift_master_ingress_ip_network_cidr=172.46.0.0/16
 
-# Configure number of bits to allocate to each host’s subnet e.g. 8
-# would mean a /24 network on the host.
-#osm_host_subnet_length=8
+# Configure number of bits to allocate to each host’s subnet e.g. 9
+# would mean a /23 network on the host.
+#osm_host_subnet_length=9
 
 # Configure master API and console ports.
 #openshift_master_api_port=8443
diff --git a/inventory/byo/hosts.ose.example b/inventory/byo/hosts.ose.example
index 2d54dfceb..be919c105 100644
--- a/inventory/byo/hosts.ose.example
+++ b/inventory/byo/hosts.ose.example
@@ -472,7 +472,7 @@ openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true',
 # network blocks should be private and should not conflict with network blocks
 # in your infrastructure that pods may require access to. Can not be changed
 # after deployment.
-#osm_cluster_network_cidr=10.1.0.0/16
+#osm_cluster_network_cidr=10.128.0.0/14
 #openshift_portal_net=172.30.0.0/16
 
 
@@ -492,9 +492,9 @@ openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true',
 # the CIDRs reserved for external IPs, nodes, pods, or services.
 #openshift_master_ingress_ip_network_cidr=172.46.0.0/16
 
-# Configure number of bits to allocate to each host’s subnet e.g. 8
-# would mean a /24 network on the host.
-#osm_host_subnet_length=8
+# Configure number of bits to allocate to each host’s subnet e.g. 9
+# would mean a /23 network on the host.
+#osm_host_subnet_length=9
 
 # Configure master API and console ports.
 #openshift_master_api_port=8443
diff --git a/roles/openshift_facts/library/openshift_facts.py b/roles/openshift_facts/library/openshift_facts.py
index 6c045e7ab..21104039a 100755
--- a/roles/openshift_facts/library/openshift_facts.py
+++ b/roles/openshift_facts/library/openshift_facts.py
@@ -901,10 +901,24 @@ def set_sdn_facts_if_unset(facts, system_facts):
             facts['common']['sdn_network_plugin_name'] = plugin
 
     if 'master' in facts:
-        if 'sdn_cluster_network_cidr' not in facts['master']:
-            facts['master']['sdn_cluster_network_cidr'] = '10.1.0.0/16'
-        if 'sdn_host_subnet_length' not in facts['master']:
-            facts['master']['sdn_host_subnet_length'] = '8'
+        # set defaults for sdn_cluster_network_cidr and sdn_host_subnet_length
+        # these might be overridden if they exist in the master config file
+        facts['master']['sdn_cluster_network_cidr'] = '10.128.0.0/14'
+        facts['master']['sdn_host_subnet_length'] = '9'
+
+        master_cfg_path = os.path.join(facts['common']['config_base'],
+                                       'master/master-config.yaml')
+        if os.path.isfile(master_cfg_path):
+            with open(master_cfg_path, 'r') as master_cfg_f:
+                config = yaml.safe_load(master_cfg_f.read())
+
+            if 'networkConfig' in config:
+                if 'clusterNetworkCIDR' in config['networkConfig']:
+                    facts['master']['sdn_cluster_network_cidr'] = \
+                        config['networkConfig']['clusterNetworkCIDR']
+                if 'hostSubnetLength' in config['networkConfig']:
+                    facts['master']['sdn_host_subnet_length'] = \
+                        config['networkConfig']['hostSubnetLength']
 
     if 'node' in facts and 'sdn_mtu' not in facts['node']:
         node_ip = facts['common']['ip']
@@ -1771,8 +1785,8 @@ class OpenShiftFacts(object):
         facts = set_node_schedulability(facts)
         facts = set_selectors(facts)
         facts = set_identity_providers_if_unset(facts)
-        facts = set_sdn_facts_if_unset(facts, self.system_facts)
         facts = set_deployment_facts_if_unset(facts)
+        facts = set_sdn_facts_if_unset(facts, self.system_facts)
         facts = set_container_facts_if_unset(facts)
         facts = build_kubelet_args(facts)
         facts = build_controller_args(facts)