Test

Author: jfreden

server/src/internalClusterTest/java/org/elasticsearch/reservedstate/service/FileSettingsServiceIT.java

@@ -134,6 +134,11 @@ private void assertMasterNode(Client client, String node) {
 
     public static void writeJSONFile(String node, String json, Logger logger, Long version) throws Exception {
         FileSettingsService fileSettingsService = internalCluster().getInstance(FileSettingsService.class, node);
+        writeJSONFile(node, json, logger, version, fileSettingsService.watchedFile());
+    }
+
+    public static void writeJSONFile(String node, String json, Logger logger, Long version, Path targetPath) throws Exception {
+        FileSettingsService fileSettingsService = internalCluster().getInstance(FileSettingsService.class, node);
 
         Files.createDirectories(fileSettingsService.watchedFileDir());
         Path tempFilePath = createTempFile();
@@ -147,8 +152,8 @@ public static void writeJSONFile(String node, String json, Logger logger, Long v
         do {
             try {
                 // this can fail on Windows because of timing
-                Files.move(tempFilePath, fileSettingsService.watchedFile(), StandardCopyOption.ATOMIC_MOVE);
-                logger.info("--> after writing JSON config to node {} with path {}", node, tempFilePath);
+                Files.move(tempFilePath, targetPath, StandardCopyOption.ATOMIC_MOVE);
+                logger.info("--> after writing JSON config to node {} with path {}", node, targetPath);
                 return;
             } catch (IOException e) {
                 logger.info("--> retrying writing a settings file [{}]", retryCount);
@@ -498,6 +503,55 @@ public void testSettingsAppliedOnMasterReElection() throws Exception {
         assertClusterStateSaveOK(savedClusterState.v1(), savedClusterState.v2(), "43mb");
     }
 
+    public void testSymlinkUpdateTriggerReload() throws Exception {
+        internalCluster().setBootstrapMasterNodeIndex(0);
+        logger.info("--> start data node / non master node");
+        String dataNode = internalCluster().startNode(Settings.builder().put(dataOnlyNode()).put("discovery.initial_state_timeout", "1s"));
+        FileSettingsService dataFileSettingsService = internalCluster().getInstance(FileSettingsService.class, dataNode);
+
+        assertFalse(dataFileSettingsService.watching());
+
+        logger.info("--> start master node");
+        final String masterNode = internalCluster().startMasterOnlyNode();
+        assertMasterNode(internalCluster().nonMasterClient(), masterNode);
+        {
+            var savedClusterState = setupClusterStateListener(masterNode);
+
+            FileSettingsService masterFileSettingsService = internalCluster().getInstance(FileSettingsService.class, masterNode);
+
+            assertBusy(() -> assertTrue(masterFileSettingsService.watching()));
+            assertFalse(dataFileSettingsService.watching());
+
+            createK8sLikeMount(masterNode);
+            assertClusterStateSaveOK(savedClusterState.v1(), savedClusterState.v2(), "50mb");
+        }
+        {
+            var savedClusterState = setupClusterStateListener(masterNode);
+            updateSymbolicLink(masterNode, testJSON43mb);
+            assertClusterStateSaveOK(savedClusterState.v1(), savedClusterState.v2(), "43mb");
+        }
+    }
+
+    public Path createK8sLikeMount(String node) throws Exception {
+        FileSettingsService fileSettingsService = internalCluster().getInstance(FileSettingsService.class, node);
+        Path baseDir = fileSettingsService.watchedFileDir();
+        var fileDir = Files.createDirectories(baseDir.resolve("..TIMESTAMP_TEMP_FOLDER_1"));
+        writeJSONFile(node, testJSON, logger, versionCounter.incrementAndGet(), fileDir.resolve("settings.json"));
+
+        var dataDir = Files.createSymbolicLink(baseDir.resolve("..data"), fileDir.getFileName());
+
+        return Files.createSymbolicLink(baseDir.resolve("settings.json"), dataDir.getFileName().resolve("settings.json"));
+    }
+
+    public void updateSymbolicLink(String node, String json) throws Exception {
+        FileSettingsService fileSettingsService = internalCluster().getInstance(FileSettingsService.class, node);
+        Path baseDir = fileSettingsService.watchedFileDir();
+        var fileDir = Files.createDirectories(baseDir.resolve("..TIMESTAMP_TEMP_FOLDER_2"));
+        writeJSONFile(node, json, logger, versionCounter.incrementAndGet(), fileDir.resolve("settings.json"));
+        Files.deleteIfExists(baseDir.resolve("..data"));
+        Files.createSymbolicLink(baseDir.resolve("..data"), fileDir.getFileName());
+    }
+
     private void assertHasErrors(AtomicLong waitForMetadataVersion, String expectedError) {
         var errorMetadata = getErrorMetadata(waitForMetadataVersion);
         assertThat(errorMetadata, is(notNullValue()));