Floating IP assignment to support specific port

When creating VMs with more than one port, the floating IP assignment
can randomly choose one of the created ports, potentially leading to
failures.

This patch aims to provide a way to specify which port to assign the
floating IP to. The network where the port lives must be specified
thus the assignment becomes deterministic.

This patch should keep compatibility with previous versions of the
neutron_floating_ip module.

Signed-off-by: Abel Navarro <abel@midokura.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/neutron_floating_ip b/neutron_floating_ip
index 1ddd4d2..e4df081 100644
--- a/neutron_floating_ip
+++ b/neutron_floating_ip
@@ -67,6 +67,11 @@ options:
         - Name of the network from which IP has to be assigned to VM. Please make sure the network is an external network
      required: true
      default: None
+   port_network_name:
+     description:
+        - Name of the network where the VM port lives. Useful when the VM has more than one port
+     required: false
+     default: None
    instance_name:
      description:
         - The name of the instance to which the IP address should be assigned
@@ -133,9 +138,19 @@ def _get_server_state(module, nova):
     return server_info, server
                                  
 def _get_port_info(neutron, module, instance_id):
-    kwargs = {
-            'device_id': instance_id,
-    }
+    if module.params['port_network_name'] is None:
+      kwargs = {
+              'device_id': instance_id
+      }
+    else:
+      network_id = _get_net_id(neutron, module.params['port_network_name'])
+      if not network_id:
+            module.fail_json(msg = "cannot find the network specified, please check")
+
+      kwargs = {
+              'device_id': instance_id,
+              'network_id': network_id
+      }
     try:
         ports = neutron.list_ports(**kwargs)
     except Exception as e:
@@ -167,9 +182,9 @@ def _create_floating_ip(neutron, module, port_id, net_id):
         module.fail_json(msg="There was an error in updating the floating ip address: %s" % e.message)
     module.exit_json(changed=True, result=result, public_ip=result['floatingip']['floating_ip_address'])
 
-def _get_net_id(neutron, module):
+def _get_net_id(neutron, network_name):
     kwargs = {
-        'name': module.params['network_name'],
+        'name': network_name,
     }
     try:
         networks = neutron.list_networks(**kwargs)
@@ -201,6 +216,7 @@ def main():
             region_name = dict(default=None),
             network_name = dict(required=True),
             instance_name = dict(required=True),
+            port_network_name = dict(default=None),
             state = dict(default='present', choices=['absent', 'present'])
         ),
     )
@@ -225,7 +241,7 @@ def main():
     if module.params['state'] == 'present':
         if floating_ip:
             module.exit_json(changed = False, public_ip=floating_ip)
-        net_id = _get_net_id(neutron, module)
+        net_id = _get_net_id(neutron, module.params['network_name'])
         if not net_id:
             module.fail_json(msg = "cannot find the network specified, please check")
         _create_floating_ip(neutron, module, port_id, net_id)