Adds REST API support for Fixed IPs

This adds an extension that provides a REST API for getting information
about a fixed ip, reserving a fixed ip and unreserving a fixed ip. The
interface is accessed via

/v2/{tenant_id}/os-fixed-ips/<ip_address> # GET ip info
/v2/{tenant_id}/os-fixed-ips/<ip_address>/action # POST reserve/unreserve ip

This forms part of the work to provide APIs for functionality currently
implemented by nova-manage that needs direct db access so nova-manage
can eventually be removed

Adds db function fixed_ip_get_by_address_detailed in order to optimise being able
to get the instance and network information for a fixed ip at the same
time as the rest of the fixed ip information

Change-Id: I92edf4e6b74b14bb9c49d5bc0c79e40d3a496bc5
Implements: blueprint apis-for-nova-manage
DocImpact

2 files changed, 28 insertions, 0 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index 04786a1fb..45686d9ef 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -466,6 +466,11 @@ def fixed_ip_get_by_address(context, address):
     return IMPL.fixed_ip_get_by_address(context, address)
 
 
+def fixed_ip_get_by_address_detailed(context, address):
+    """Get detailed fixed ip info by address or raise if it does not exist."""
+    return IMPL.fixed_ip_get_by_address_detailed(context, address)
+
+
 def fixed_ip_get_by_instance(context, instance_uuid):
     """Get fixed ips by instance or raise if none exist."""
     return IMPL.fixed_ip_get_by_instance(context, instance_uuid)
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 72caad74d..bc92aaa62 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -1151,6 +1151,29 @@ def fixed_ip_get_by_address(context, address, session=None):
     return result
 
 
+@require_admin_context
+def fixed_ip_get_by_address_detailed(context, address, session=None):
+    # This method returns a tuple of (models.FixedIp, models.Network,
+    # models.Instance).
+    if not session:
+        session = get_session()
+
+    result = session.query(models.FixedIp, models.Network, models.Instance).\
+        filter_by(address=address).\
+        outerjoin((models.Network,
+                   models.Network.id ==
+                   models.FixedIp.network_id)).\
+        outerjoin((models.Instance,
+                   models.Instance.uuid ==
+                   models.FixedIp.instance_uuid)).\
+        first()
+
+    if not result:
+        raise exception.FixedIpNotFoundForAddress(address=address)
+
+    return result
+
+
 @require_context
 def fixed_ip_get_by_instance(context, instance_uuid):
     if not uuidutils.is_uuid_like(instance_uuid):