Do not allow creation of two big/small networks

- Networks smaller than /29 are not supported in Ganeti.
- Big networks will result in degraded performance in Ganeti
and DB due to the big reservation map.

snf-cyclades-app/synnefo/api/management/commands/network-create.py

@@ -36,8 +36,9 @@ from optparse import make_option
 from django.core.management.base import BaseCommand, CommandError
 
 from synnefo.db.models import Network, Backend
-from synnefo.api.util import network_link_from_type
+from synnefo.api.util import network_link_from_type, validate_network_size
 from synnefo.logic.backend import create_network
+from synnefo import settings
 
 import ipaddr
 
@@ -47,6 +48,8 @@ NETWORK_TYPES = ['PUBLIC_ROUTED', 'PRIVATE_MAC_FILTERED',
 
 
 class Command(BaseCommand):
+    can_import_settings = True
+
     help = "Create a new network"
 
     option_list = BaseCommand.option_list + (
@@ -154,7 +157,6 @@ class Command(BaseCommand):
             create_network(network)
 
 
-
 def validate_network_info(options):
     subnet = options['subnet']
     gateway = options['gateway']
@@ -162,7 +164,12 @@ def validate_network_info(options):
     gateway6 = options['gateway6']
 
     try:
-        ipaddr.IPv4Network(subnet)
+        net = ipaddr.IPv4Network(subnet)
+        prefix = net.prefixlen
+        if not validate_network_size(prefix):
+            raise CommandError("Unsupport network mask %d."
+                               " Must be in range (%s,29] "
+                               % (prefix, settings.MAX_CIDR_BLOCK))
     except ValueError:
         raise CommandError('Malformed subnet')
     try:

snf-cyclades-app/synnefo/api/networks.py

@@ -48,7 +48,6 @@ from synnefo.api.faults import (BadRequest, Unauthorized,
                                 NetworkInUse, OverLimit)
 from synnefo.db.models import Network, Pool
 from synnefo.logic import backend
-from synnefo.settings import MAX_CIDR_BLOCK
 
 
 log = getLogger('synnefo.api')
@@ -179,9 +178,8 @@ def create_network(request):
         raise OverLimit('Network count limit exceeded for your account.')
 
     cidr_block = int(subnet.split('/')[1])
-    if cidr_block <= MAX_CIDR_BLOCK:
-        raise OverLimit("Network size is to big. Please specify a network"
-                        " smaller than /" + str(MAX_CIDR_BLOCK) + '.')
+    if not util.validate_network_size(cidr_block):
+        raise OverLimit("Unsupported network size.")
 
     try:
         link = util.network_link_from_type(typ)

snf-cyclades-app/synnefo/api/util.py

@@ -64,6 +64,7 @@ from synnefo.db.models import (Flavor, VirtualMachine, VirtualMachineMetadata,
 from synnefo.lib.astakos import get_user
 from synnefo.plankton.backend import ImageBackend
 from synnefo.logic import ippool
+from synnefo.settings import MAX_CIDR_BLOCK
 
 
 log = getLogger('synnefo.api')
@@ -209,6 +210,11 @@ def get_network(network_id, user_id):
         raise ItemNotFound('Network not found.')
 
 
+def validate_network_size(cidr_block):
+    """Return True if network size is allowed."""
+    return cidr_block <= 29 and cidr_block > MAX_CIDR_BLOCK
+
+
 def backend_public_networks(backend):
     """Return available public networks of the backend.