server: fix available hypervisors listing for a zone

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

@@ -32,7 +32,6 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Random;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 import javax.inject.Inject;
@@ -60,10 +59,8 @@
 import org.apache.cloudstack.storage.datastore.db.PrimaryDataStoreDao;
 import org.apache.cloudstack.storage.datastore.db.StoragePoolVO;
 import org.apache.cloudstack.utils.identity.ManagementServerNode;
-
 import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.lang.ObjectUtils;
-
 import org.springframework.stereotype.Component;
 
 import com.cloud.agent.AgentManager;
@@ -175,6 +172,7 @@
 import com.cloud.storage.dao.VolumeDao;
 import com.cloud.user.Account;
 import com.cloud.user.AccountManager;
+import com.cloud.utils.StringUtils;
 import com.cloud.utils.Ternary;
 import com.cloud.utils.UriUtils;
 import com.cloud.utils.component.Manager;
@@ -201,7 +199,6 @@
 import com.cloud.utils.ssh.SSHCmdHelper;
 import com.cloud.utils.ssh.SshException;
 import com.cloud.vm.UserVmManager;
-import com.cloud.utils.StringUtils;
 import com.cloud.vm.VMInstanceVO;
 import com.cloud.vm.VirtualMachine;
 import com.cloud.vm.VirtualMachine.State;
@@ -3266,12 +3263,16 @@
 
     @Override
     public List<HypervisorType> listAvailHypervisorInZone(final Long zoneId) {
-        List<VMTemplateVO> systemVMTemplates = _templateDao.listAllReadySystemVMTemplates(zoneId);
-        final Set<HypervisorType> hypervisors = new HashSet<>();
-        for (final VMTemplateVO systemVMTemplate : systemVMTemplates) {
-            hypervisors.add(systemVMTemplate.getHypervisorType());
+        final SearchCriteria<String> sc = _hypervisorsInDC.create();
+        if (zoneId != null) {
+            sc.setParameters("dataCenter", zoneId);
         }
-        return new ArrayList<>(hypervisors);
+        sc.setParameters("type", Host.Type.Routing);
+
+        return _hostDao.customSearch(sc, null).stream()
+                // The search is not able to return list of enums, so getting
+                // list of hypervisors as strings and then converting them to enum
+                .map(HypervisorType::getType).collect(Collectors.toList());
     }
 
     @Override