[vpn] implement creating vpns

uncloud_net/services.py

@@ -4,32 +4,46 @@ from .models import *
 from .selectors import *
 
 @transaction.atomic
-def create_wireguard_vpn(*,
-               public_key: str,
-               network_mask: int
-               ) -> WireGuardVPN:
+def create_wireguard_vpn(owner, public_key, network_mask):
 
-    pool = get_suitable_pool(network_mask)[0]
+    pool = get_suitable_pools(network_mask)[0]
+    count = pool.wireguardvpn_set.count()
 
-    # FIXME: exception - which?
-    if not pools:
-        return None
+    # First object
+    if count == 0:
+        return WireGuardVPN.objects.create(owner=owner,
+                                           vpnpool=pool,
+                                           pool_index=0,
+                                           wireguard_public_key=public_key)
 
 
-        #     last_net = ipaddress.ip_network(self.used_networks.last().address)
-        #     last_net_ip = last_net[0]
+    else: # Select last network and try +1 it
+        last_net = WireGuardVPN.objects.filter(vpnpool=pool).order_by('pool_index').last()
 
-        #     if last_net_ip.version == 6:
-        #         offset_to_next = 2**(128 - self.subnetwork_size)
-        #     elif last_net_ip.version == 4:
-        #         offset_to_next = 2**(32 - self.subnetwork_size)
+        next_index = last_net.pool_index + 1
 
-        #     next_net_ip = last_net_ip + offset_to_next
+        if next_index <= pool.max_pool_index:
+            return WireGuardVPN.objects.create(owner=owner,
+                                               vpnpool=pool,
+                                               pool_index=next_index,
+                                               wireguard_public_key=public_key)
 
-        #     return str(next_net_ip)
-        # else:
-        #     # first network to be created
-        #     return self.network
+
+    # Still there? Then we need to lookup previously used networks
+    try:
+        free_lease = WireGuardVPNFreeLeases.objects.get(vpnpool=pool)
+
+        vpn = WireGuardVPN.objects.create(owner=owner,
+                                           vpnpool=pool,
+                                           pool_index=free_lease.pool_index,
+                                           wireguard_public_key=public_key)
+
+        free_lease.delete()
+
+        return vpn
+
+    except WireGuardVPNFreeLeases.DoesNotExist:
+        pass
 
     @property
     def wireguard_config_filename(self):