create rotate file on the fly for access.log

client/src/main/java/org/apache/cloudstack/ServerDaemon.java

@@ -20,8 +20,9 @@
 
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.IOException;
+import java.io.FileWriter;
 import java.io.InputStream;
+import java.io.IOException;
 import java.lang.management.ManagementFactory;
 import java.net.URL;
 import java.util.Properties;
@@ -309,9 +310,61 @@ private RequestLog createRequestLog() {
         log.setAppend(true);
         log.setLogTimeZone("GMT");
         log.setLogLatency(true);
+        createRotateFile(logPath);
         return log;
     }
 
+    private static final String LOGROTATE_CONFIG_NAME = "access";
+    private static final String[] LOGROTATE_CONFIG_DIRS = {
+            "/etc/logrotate.d",
+            "/usr/local/etc/logrotate.d",
+            "/opt/local/etc/logrotate.d"
+    };
+
+    private void createRotateFile(File logPath) {
+        final File logrotateDir = findLogrotateConfigDir();
+        if (logrotateDir == null) {
+            logger.info("No logrotate.d directory found on this system, skipping access log rotation setup");
+            return;
+        }
+
+        final File rotateConfigFile = new File(logrotateDir, LOGROTATE_CONFIG_NAME);
+        if (rotateConfigFile.exists()) {
+            logger.debug(String.format("Logrotate config [%s] already exists, leaving it untouched", rotateConfigFile.getAbsolutePath()));
+            return;
+        }
+
+        final String fileContents = logPath.getAbsolutePath() + " {\n"
+                + "  copytruncate\n"
+                + "  daily\n"
+                + "  rotate 14\n"
+                + "  compress\n"
+                + "  missingok\n"
+                + "  create 0644 cloud cloud\n"
+                + "}\n";
+        try (FileWriter fw = new FileWriter(rotateConfigFile)) {
+            fw.write(fileContents);
+        } catch (IOException e) {
+            logger.warn(String.format("Unable to create logrotate config [%s] for the access log, continuing without rotation", rotateConfigFile.getAbsolutePath()), e);
+        }
+    }
+
+    /**
+     * Finds the logrotate.d directory for this system. The path is the same across the
+     * Linux distributions CloudStack supports ({@code /etc/logrotate.d}), but is looked up
+     * rather than hardcoded so packagings that relocate it (e.g. under a custom prefix) are
+     * still honoured, and systems without logrotate installed are skipped gracefully.
+     */
+    private File findLogrotateConfigDir() {
+        for (final String candidate : LOGROTATE_CONFIG_DIRS) {
+            final File dir = new File(candidate);
+            if (dir.isDirectory()) {
+                return dir;
+            }
+        }
+        return null;
+    }
+
     private URL getResource(String aResource) {
         return Thread.currentThread().getContextClassLoader().getResource(aResource);
     }