[JENKINS-13153] - Use directory from env:BASE when writing jenkins.copies (#2992)

[JENKINS-13153] - Use directory from env:BASE when writing jenkins.copies

core/src/main/java/hudson/lifecycle/WindowsServiceLifecycle.java

@@ -60,20 +60,20 @@ public class WindowsServiceLifecycle extends Lifecycle {
      */
     private void updateJenkinsExeIfNeeded() {
         try {
-            File rootDir = Jenkins.getInstance().getRootDir();
+            File baseDir = getBaseDir();
 
             URL exe = getClass().getResource("/windows-service/jenkins.exe");
             String ourCopy = Util.getDigestOf(exe.openStream());
 
             for (String name : new String[]{"hudson.exe","jenkins.exe"}) {
                 try {
-                    File currentCopy = new File(rootDir,name);
+                    File currentCopy = new File(baseDir,name);
                     if(!currentCopy.exists())   continue;
                     String curCopy = new FilePath(currentCopy).digest();
 
                     if(ourCopy.equals(curCopy))     continue; // identical
 
-                    File stage = new File(rootDir,name+".new");
+                    File stage = new File(baseDir,name+".new");
                     FileUtils.copyURLToFile(exe,stage);
                     Kernel32.INSTANCE.MoveFileExA(stage.getAbsolutePath(),currentCopy.getAbsolutePath(),MOVEFILE_DELAY_UNTIL_REBOOT|MOVEFILE_REPLACE_EXISTING);
                     LOGGER.info("Scheduled a replacement of "+name);
@@ -107,8 +107,8 @@ public class WindowsServiceLifecycle extends Lifecycle {
         String baseName = dest.getName();
         baseName = baseName.substring(0,baseName.indexOf('.'));
 
-        File rootDir = Jenkins.getInstance().getRootDir();
-        File copyFiles = new File(rootDir,baseName+".copies");
+        File baseDir = getBaseDir();
+        File copyFiles = new File(baseDir,baseName+".copies");
 
         try (FileWriter w = new FileWriter(copyFiles, true)) {
             w.write(by.getAbsolutePath() + '>' + getHudsonWar().getAbsolutePath() + '\n');
@@ -144,6 +144,19 @@ public class WindowsServiceLifecycle extends Lifecycle {
         if(r!=0)
             throw new IOException(baos.toString());
     }
+    
+    private static final File getBaseDir() {
+        File baseDir;
+        
+        String baseEnv = System.getenv("BASE");
+        if (baseEnv != null) {
+            baseDir = new File(baseEnv);
+        } else {
+            LOGGER.log(Level.WARNING, "Could not find environment variable 'BASE' for Jenkins base directory. Falling back to JENKINS_HOME");
+            baseDir = Jenkins.getInstance().getRootDir();
+        }
+        return baseDir;
+    }
 
     private static final Logger LOGGER = Logger.getLogger(WindowsServiceLifecycle.class.getName());
 }