Stop hard-coding underscore in clone names

src/main/java/org/jenkinsci/plugins/vSphereCloudSlaveTemplate.java

@@ -82,7 +82,9 @@ public class vSphereCloudSlaveTemplate implements Describable<vSphereCloudSlaveT
     protected static final SchemeRequirement HTTP_SCHEME = new SchemeRequirement("http");
     protected static final SchemeRequirement HTTPS_SCHEME = new SchemeRequirement("https");
 
-    private final String cloneNamePrefix;
+    private int configVersion;
+    private static final int CURRENT_CONFIG_VERSION = 1;
+    private String cloneNamePrefix; // almost final
     private final String masterImageName;
     private Boolean useSnapshot; // almost final
     private final String snapshotName;
@@ -148,6 +150,7 @@ public vSphereCloudSlaveTemplate(final String cloneNamePrefix,
                                      final RetentionStrategy<?> retentionStrategy,
                                      final List<? extends NodeProperty<?>> nodeProperties,
                                      final List<? extends VSphereGuestInfoProperty> guestInfoProperties) {
+        this.configVersion = CURRENT_CONFIG_VERSION;
         this.cloneNamePrefix = cloneNamePrefix;
         this.masterImageName = masterImageName;
         this.snapshotName = snapshotName;
@@ -349,6 +352,38 @@ protected Object readResolve() {
                 LOGGER.log(Level.CONFIG, " - Failed to reconfigure strategy", ex);
             }
         }
+        // Earlier versions of the code may have stored configuration in a
+        // different way but in the same kind of fields, so we need an explicit
+        // versioning to know how to mutate the data.
+        if( configVersion<=0) {
+            LOGGER.log(Level.CONFIG,
+                    "{0} loaded old configuration that had hard-coded underscore at the end of the cloneNamePrefix.",
+                    this);
+            // In version one, the underscore was removed from the code so we
+            // have to put it in the data (the user is then free to change it to
+            // something else if they want to).
+            this.cloneNamePrefix = this.cloneNamePrefix + "_";
+            configVersion = 1;
+        }
+        // Note: Subsequent changes dependent on configVersion should go above
+        // this line.
+        if (configVersion < CURRENT_CONFIG_VERSION) {
+            throw new IllegalStateException("Internal error: configVersion==" + configVersion
+                    + " at end of readResolve method, but the current config version should be "
+                    + CURRENT_CONFIG_VERSION
+                    + ".  Either CURRENT_CONFIG_VERSION is incorrect or the readResolve method is not setting configVersion when it upgrades the data.");
+        }
+        if( configVersion > CURRENT_CONFIG_VERSION ) {
+            LOGGER.log(Level.WARNING,
+                    "{0} was defined by a later version of the plugin "
+                            + "(one that saved with configVersion={1}, whereas this version of the plugin is expecting {2}).  "
+                            + "The code may not function as expected.",
+                    new Object[]{
+                            this,
+                            configVersion,
+                            CURRENT_CONFIG_VERSION
+                    });
+        }
         return this;
     }
 

src/main/java/org/jenkinsci/plugins/vsphere/tools/CloudProvisioningAlgorithm.java

@@ -44,15 +44,17 @@ public static CloudProvisioningRecord findTemplateWithMostFreeCapacity(
     }
 
     /**
-     * Chooses a name for a new node.
+     * Chooses a name for a new node. The name will start with the
+     * {@link vSphereCloudSlaveTemplate#getCloneNamePrefix()}.
      * <ul>
      * <li>If the template has a limited number of instances available then the
-     * name will be of the form "prefix_number" where "number" is a number that
-     * should be between 1 and the number of permitted instances.</li>
+     * name will be of the form "prefix<i>number</i>" where "<i>number</i>" is a
+     * number that should be between 1 and the number of permitted instances.
+     * </li>
      * <li>If the template has an unlimited number of instances available then
-     * the name will be of the form "prefix_random" where "random" is a random
-     * UUID's 32-byte number (rendered using a high radix to keep the string
-     * short).</li>
+     * the name will be of the form "prefix<i>random</i>" where "<i>random</i>"
+     * is a random UUID's 32-byte (128 bit) number (rendered using a high radix
+     * to keep the string short).</li>
      * </ul>
      * 
      * @param record

src/main/resources/org/jenkinsci/plugins/vSphereCloudSlaveTemplate/help-cloneNamePrefix.html

@@ -1,6 +1,6 @@
 <div>
 Controls the name by which the virtual machine will be known to vSphere.
-The plug-in will append an underscore and a unique ID to this prefix in order to generate unique names.<p>
+The plug-in will append a unique ID to this prefix in order to generate unique names.<p>
 Note: You must ensure that no virtual machines (other than those created by this template) have names starting with this prefix.
 </p>
 </div>