Add simple linux bridge as network environment

Create a bridge for the overcloud services using linux bridge instead of
openvswitch. Some SDNs may be incompatible with openvswitch datapath.

Change-Id: I873368e74ddfd95bf5c6e1f88cec33ba011e09dd

net-config-linux-bridge.yaml

@@ -0,0 +1,73 @@
+heat_template_version: 2015-04-30
+
+description: >
+  Software Config to drive os-net-config for a simple bridge.
+
+parameters:
+  ControlPlaneIp:
+    default: ''
+    description: IP address/subnet on the ctlplane network
+    type: string
+  ExternalIpSubnet:
+    default: ''
+    description: IP address/subnet on the external network
+    type: string
+  InternalApiIpSubnet:
+    default: ''
+    description: IP address/subnet on the internal API network
+    type: string
+  StorageIpSubnet:
+    default: ''
+    description: IP address/subnet on the storage network
+    type: string
+  StorageMgmtIpSubnet:
+    default: ''
+    description: IP address/subnet on the storage mgmt network
+    type: string
+  TenantIpSubnet:
+    default: ''
+    description: IP address/subnet on the tenant network
+    type: string
+  ControlPlaneDefaultRoute: # Override this via parameter_defaults
+    description: The default route of the control plane network.
+    type: string
+    default: '192.0.2.1'
+  EC2MetadataIp: # Override this via parameter_defaults
+    description: The IP address of the EC2 metadata server.
+    type: string
+    default: '169.254.169.254/32'
+
+
+resources:
+  OsNetConfigImpl:
+    type: OS::Heat::StructuredConfig
+    properties:
+      group: os-apply-config
+      config:
+        os_net_config:
+          network_config:
+            -
+              type: linux_bridge
+              name: {get_input: bridge_name}
+              addresses:
+                -
+                  ip_netmask: {get_param: ControlPlaneIp}
+              members:
+                -
+                  type: interface
+                  name: {get_input: interface_name}
+                  # force the MAC address of the bridge to this interface
+                  primary: true
+              routes:
+                -
+                  ip_netmask: 0.0.0.0/0
+                  next_hop: {get_param: ControlPlaneDefaultRoute}
+                  default: true
+                -
+                  ip_netmask: {get_param: EC2MetadataIp}
+                  next_hop: {get_param: ControlPlaneDefaultRoute}
+
+outputs:
+  OS::stack_id:
+    description: The OsNetConfigImpl resource.
+    value: {get_resource: OsNetConfigImpl}