Ability to put a server in Down state to maintenance (#4363)

Author: ravening

server/src/main/java/com/cloud/configuration/ConfigurationManagerImpl.java

@@ -415,10 +415,12 @@ public class ConfigurationManagerImpl extends ManagerBase implements Configurati
             "Maximum IOPS read burst duration (seconds). If '0' (zero) then does not check for maximum burst length.", true, ConfigKey.Scope.Global, null);
     public final static ConfigKey<Long> IOPS_MAX_WRITE_LENGTH = new ConfigKey<Long>(Long.class, "vm.disk.iops.maximum.write.length", "Advanced", "0",
             "Maximum IOPS write burst duration (seconds). If '0' (zero) then does not check for maximum burst length.", true, ConfigKey.Scope.Global, null);
-
     public static final ConfigKey<Boolean> ADD_HOST_ON_SERVICE_RESTART_KVM = new ConfigKey<Boolean>(Boolean.class, "add.host.on.service.restart.kvm", "Advanced", "true",
             "Indicates whether the host will be added back to cloudstack after restarting agent service on host. If false it wont be added back even after service restart",
             true, ConfigKey.Scope.Global, null);
+    public static final ConfigKey<Boolean> SET_HOST_DOWN_TO_MAINTENANCE = new ConfigKey<Boolean>(Boolean.class, "set.host.down.to.maintenance", "Advanced", "false",
+                        "Indicates whether the host in down state can be put into maintenance state so thats its not enabled after it comes back.",
+                        true, ConfigKey.Scope.Zone, null);
 
     private static final String IOPS_READ_RATE = "IOPS Read";
     private static final String IOPS_WRITE_RATE = "IOPS Write";
@@ -6437,6 +6439,6 @@ public String getConfigComponentName() {
     @Override
     public ConfigKey<?>[] getConfigKeys() {
         return new ConfigKey<?>[] {SystemVMUseLocalStorage, IOPS_MAX_READ_LENGTH, IOPS_MAX_WRITE_LENGTH,
-                BYTES_MAX_READ_LENGTH, BYTES_MAX_WRITE_LENGTH, ADD_HOST_ON_SERVICE_RESTART_KVM};
+                BYTES_MAX_READ_LENGTH, BYTES_MAX_WRITE_LENGTH, ADD_HOST_ON_SERVICE_RESTART_KVM, SET_HOST_DOWN_TO_MAINTENANCE};
     }
 }

server/src/main/java/com/cloud/resource/ResourceManagerImpl.java

@@ -180,6 +180,9 @@
 import com.cloud.vm.dao.VMInstanceDao;
 import com.google.gson.Gson;
 
+
+import static com.cloud.configuration.ConfigurationManagerImpl.SET_HOST_DOWN_TO_MAINTENANCE;
+
 @Component
 public class ResourceManagerImpl extends ManagerBase implements ResourceManager, ResourceService, Manager {
     private static final Logger s_logger = Logger.getLogger(ResourceManagerImpl.class);
@@ -1302,6 +1305,17 @@ public Host maintain(final PrepareForMaintenanceCmd cmd) {
             throw new CloudRuntimeException("Host is already in state " + host.getResourceState() + ". Cannot recall for maintenance until resolved.");
         }
 
+        if (SET_HOST_DOWN_TO_MAINTENANCE.valueIn(host.getDataCenterId()) && (host.getStatus() == Status.Down)) {
+            if (host.getResourceState() == ResourceState.Enabled) {
+                _hostDao.updateResourceState(ResourceState.Enabled, ResourceState.Event.AdminAskMaintenance, ResourceState.PrepareForMaintenance, host);
+                _hostDao.updateResourceState(ResourceState.PrepareForMaintenance, ResourceState.Event.InternalEnterMaintenance, ResourceState.Maintenance, host);
+                return _hostDao.findById(hostId);
+            } else if (host.getResourceState() == ResourceState.ErrorInMaintenance) {
+                _hostDao.updateResourceState(ResourceState.ErrorInMaintenance, ResourceState.Event.InternalEnterMaintenance, ResourceState.Maintenance, host);
+                return _hostDao.findById(hostId);
+            }
+        }
+
         if (_hostDao.countBy(host.getClusterId(), ResourceState.PrepareForMaintenance, ResourceState.ErrorInPrepareForMaintenance) > 0) {
             throw new CloudRuntimeException("There are other servers attempting migrations for maintenance. " +
                     "Found hosts in PrepareForMaintenance OR ErrorInPrepareForMaintenance STATUS in cluster " + host.getClusterId());