Fix IP conflict (#40)

Co-authored-by: Pearl Dsilva <pearl.dsilva@shapeblue.com>

Author: Pearl1594

server/src/com/cloud/network/IpAddressManagerImpl.java

@@ -30,6 +30,8 @@
 import javax.inject.Inject;
 
 import com.cloud.dc.DomainVlanMapVO;
+
+import org.apache.cloudstack.api.ApiConstants;
 import org.apache.log4j.Logger;
 
 import org.apache.cloudstack.acl.ControlledEntity.ACLType;
@@ -102,6 +104,8 @@
 import com.cloud.network.dao.LoadBalancerDao;
 import com.cloud.network.dao.NetworkAccountDao;
 import com.cloud.network.dao.NetworkDao;
+import com.cloud.network.dao.NetworkDetailVO;
+import com.cloud.network.dao.NetworkDetailsDao;
 import com.cloud.network.dao.NetworkDomainDao;
 import com.cloud.network.dao.NetworkServiceMapDao;
 import com.cloud.network.dao.PhysicalNetworkDao;
@@ -289,6 +293,8 @@ public class IpAddressManagerImpl extends ManagerBase implements IpAddressManage
     DataCenterIpAddressDao _privateIPAddressDao;
     @Inject
     HostPodDao _hpDao;
+    @Inject
+    NetworkDetailsDao _networkDetailsDao;
 
     SearchBuilder<IPAddressVO> AssignIpAddressSearch;
     SearchBuilder<IPAddressVO> AssignIpAddressFromPodVlanSearch;
@@ -766,9 +772,17 @@ public IPAddressVO doInTransaction(TransactionStatus status) throws Insufficient
                 }
                 sc.setJoinParameters("vlan", "type", vlanUse);
 
+                String routerIpAddress = null;
+                if (network != null) {
+                    NetworkDetailVO routerIpDetail = _networkDetailsDao.findDetail(network.getId(), ApiConstants.ROUTER_IP);
+                    routerIpAddress = routerIpDetail != null ? routerIpDetail.getValue() : null;
+                }
+
                 if (requestedIp != null) {
                     sc.addAnd("address", SearchCriteria.Op.EQ, requestedIp);
                     errorMessage.append(": requested ip " + requestedIp + " is not available");
+                } else if (routerIpAddress != null) {
+                    sc.addAnd("address", Op.NEQ, routerIpAddress);
                 }
 
                 boolean ascOrder = ! forSystemVms;