kvm: remove unused private members reported by PMD

Running PMD's UnusedPrivateMethod, UnusedPrivateField and
UnusedLocalVariable rules over the module reported these, each verified
by hand against the sources and the tests:

  LibvirtComputingResource: field host, field gson, method
    executeBashScript, local devNum in configureIpAddresses, local
    brname in destroyNetworkRulesForVM
  LibvirtConnection: field s_connection
  LibvirtStorageAdaptor: field _manageSnapshotPath and its lookup of
    managesnapshot.sh, which the adaptor never ran
  LibvirtMigrateCommandWrapper: method isClvmBlockDevice
  LibvirtCopyToSecondaryStorageWrapper: local success
  LibvirtCreateDiskOnlyVMSnapshotCommandWrapper: two unused copies of
    the volume list

Left as reported: getPifs and getOvsPifs are called and were flagged in
error, and the write-only fields _crash and _readonly in LibvirtVMDef
are kept because dropping them would silently turn their setters into
no-ops.

Author: wido

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java

@@ -255,7 +255,6 @@
 import com.cloud.vm.VirtualMachine.PowerState;
 import com.cloud.vm.VmDetailConstants;
 
-import com.google.gson.Gson;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
@@ -439,7 +438,6 @@ public class LibvirtComputingResource extends ServerResourceBase implements Serv
     private String setupTungstenVrouterPath;
     private String updateTungstenLoadbalancerStatsPath;
     private String updateTungstenLoadbalancerSslPath;
-    private String host;
 
     private String dcId;
     private String clusterId;
@@ -599,7 +597,6 @@ public class LibvirtComputingResource extends ServerResourceBase implements Serv
 
     private boolean isReconcileCommandsEnabled = false;
 
-    private static Gson gson = new Gson();
 
     /**
      * Virsh command to set the memory balloon stats period.<br><br>
@@ -2747,7 +2744,6 @@ protected ExecutionResult prepareNetworkElementCommand(final IpAssocVpcCommand c
             conn = getLibvirtUtilitiesHelper().getConnectionByVmName(routerName);
             Pair<Map<String, Integer>, Integer> macAddressToNicNumPair = getMacAddressToNicNumPair(conn, routerName);
             final Map<String, Integer> macAddressToNicNum = macAddressToNicNumPair.first();
-            Integer devNum = macAddressToNicNumPair.second();
 
             final IpAddressTO[] ips = cmd.getIpAddresses();
             for (final IpAddressTO ip : ips) {
@@ -5080,10 +5076,6 @@ public List<DiskDef> getDisks(final Connect conn, final String vmName) {
         }
     }
 
-    private String executeBashScript(final String script) {
-        return createScript(script).execute();
-    }
-
     private Script createScript(final String script) {
         final Script command = new Script("/bin/bash", timeout, LOGGER);
         command.add("-c");
@@ -5606,7 +5598,6 @@ public boolean destroyNetworkRulesForNic(final Connect conn, final String vmName
         }
 
         final InterfaceDef intf = intfs.get(nic.getDeviceId());
-        final String brname = intf.getBrName();
         final String vif = intf.getDevName();
 
         final Script cmd = new Script(securityGroupPath, timeout, LOGGER);

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtConnection.java

@@ -34,7 +34,6 @@ public class LibvirtConnection {
     protected static Logger LOGGER = LogManager.getLogger(LibvirtConnection.class);
     static private Map<String, Connect> s_connections = new HashMap<String, Connect>();
 
-    static private Connect s_connection;
     static private String s_hypervisorURI;
     static private Thread libvirtEventThread;
 

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCopyToSecondaryStorageWrapper.java

@@ -47,8 +47,6 @@ public Answer execute(CopyToSecondaryStorageCommand command, LibvirtComputingRes
         KVMStoragePoolManager storagePoolMgr = libvirtResource.getStoragePoolMgr();
         KVMStoragePool secondaryPool;
 
-        boolean success;
-
         secondaryPool = storagePoolMgr.getStoragePoolByURI(secondaryStorageUrl);
         String mountPoint = secondaryPool.getLocalPath();
 

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateDiskOnlyVMSnapshotCommandWrapper.java

@@ -96,7 +96,6 @@ protected Answer takeDiskOnlyVmSnapshotOfRunningVm(CreateDiskOnlyVmSnapshotComma
         try {
             LibvirtUtilitiesHelper libvirtUtilitiesHelper = resource.getLibvirtUtilitiesHelper();
             Connect conn = libvirtUtilitiesHelper.getConnection();
-            List<VolumeObjectTO> volumeObjectTOS = cmd.getVolumeTOs();
             List<LibvirtVMDef.DiskDef> disks = resource.getDisks(conn, vmName);
 
             dm = resource.getDomain(conn, vmName);
@@ -164,7 +163,6 @@ protected Answer takeDiskOnlyVmSnapshotOfStoppedVm(CreateDiskOnlyVmSnapshotComma
         Map<String, Long> mapVolumeToSnapshotSize = new HashMap<>();
         String nvramSnapshotPath = null;
 
-        List<VolumeObjectTO> volumeObjectTos = cmd.getVolumeTOs();
         KVMStoragePoolManager storagePoolMgr = resource.getStoragePoolMgr();
         try {
             nvramSnapshotPath = backupNvramIfNeeded(cmd, resource);

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtMigrateCommandWrapper.java

@@ -1082,13 +1082,6 @@ public static String maskSensitiveInfoInXML(String xmlDesc) {
                 "$1*****$3");
     }
 
-    private boolean isClvmBlockDevice(MigrateCommand.MigrateDiskInfo diskInfo) {
-        if (diskInfo == null ||diskInfo.getDestPoolType() == null) {
-            return false;
-        }
-        return (Storage.StoragePoolType.CLVM.equals(diskInfo.getDestPoolType()) || Storage.StoragePoolType.CLVM_NG.equals(diskInfo.getDestPoolType()));
-    }
-
     /**
      * Determines if the driver type should be updated during migration based on CLVM involvement.
      * The driver type needs to be updated when:

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/LibvirtStorageAdaptor.java

@@ -85,7 +85,6 @@ public class LibvirtStorageAdaptor implements StorageAdaptor {
     protected Logger logger = LogManager.getLogger(getClass());
     private StorageLayer _storageLayer;
     private String _mountPoint = "/mnt";
-    private String _manageSnapshotPath;
     private static final ConcurrentHashMap<String, Integer> storagePoolRefCounts = new ConcurrentHashMap<>();
 
     private String rbdTemplateSnapName = "cloudstack-base-snap";
@@ -106,7 +105,6 @@ public class LibvirtStorageAdaptor implements StorageAdaptor {
 
     public LibvirtStorageAdaptor(StorageLayer storage) {
         _storageLayer = storage;
-        _manageSnapshotPath = Script.findScript("scripts/storage/qcow2/", "managesnapshot.sh");
     }
 
     @Override