No longer allow cluster name in data path

In 5.x we allowed this with a deprecation warning. This removes the code
added for that deprecation, requiring the cluster name to not be in the
data path.

Resolves #20391

core/src/main/java/org/elasticsearch/bootstrap/Security.java

@@ -257,11 +257,6 @@ final class Security {
         for (Path path : environment.dataFiles()) {
             addPath(policy, Environment.PATH_DATA_SETTING.getKey(), path, "read,readlink,write,delete");
         }
-        // TODO: this should be removed in ES 6.0! We will no longer support data paths with the cluster as a folder
-        // https://github.com/elastic/elasticsearch/issues/20391
-        for (Path path : environment.dataWithClusterFiles()) {
-            addPathIfExists(policy, Environment.PATH_DATA_SETTING.getKey(), path, "read,readlink,write,delete");
-        }
         for (Path path : environment.repoFiles()) {
             addPath(policy, Environment.PATH_REPO_SETTING.getKey(), path, "read,readlink,write,delete");
         }

core/src/main/java/org/elasticsearch/env/NodeEnvironment.java

@@ -209,13 +209,6 @@ public final class NodeEnvironment  implements Closeable {
                 for (int dirIndex = 0; dirIndex < environment.dataFiles().length; dirIndex++) {
                     Path dataDirWithClusterName = environment.dataWithClusterFiles()[dirIndex];
                     Path dataDir = environment.dataFiles()[dirIndex];
-                    // TODO: Remove this in 6.0, we are no longer going to read from the cluster name directory
-                    if (readFromDataPathWithClusterName(dataDirWithClusterName)) {
-                        DeprecationLogger deprecationLogger = new DeprecationLogger(startupTraceLogger);
-                        deprecationLogger.deprecated("ES has detected the [path.data] folder using the cluster name as a folder [{}], " +
-                                        "Elasticsearch 6.0 will not allow the cluster name as a folder within the data path", dataDir);
-                        dataDir = dataDirWithClusterName;
-                    }
                     Path dir = dataDir.resolve(NODES_FOLDER).resolve(Integer.toString(possibleLockId));
                     Files.createDirectories(dir);
 
@@ -289,25 +282,6 @@ public final class NodeEnvironment  implements Closeable {
         }
     }
 
-    // Visible for testing
-    /** Returns true if data should be read from the data path that includes the cluster name (ie, it has data in it) */
-    static boolean readFromDataPathWithClusterName(Path dataPathWithClusterName) throws IOException {
-        if (Files.exists(dataPathWithClusterName) == false ||          // If it doesn't exist
-                Files.isDirectory(dataPathWithClusterName) == false || // Or isn't a directory
-                dirEmpty(dataPathWithClusterName)) {                   // Or if it's empty
-            // No need to read from cluster-name folder!
-            return false;
-        }
-        // The "nodes" directory inside of the cluster name
-        Path nodesPath = dataPathWithClusterName.resolve(NODES_FOLDER);
-        if (Files.isDirectory(nodesPath)) {
-            // The cluster has data in the "nodes" so we should read from the cluster-named folder for now
-            return true;
-        }
-        // Hey the nodes directory didn't exist, so we can safely use whatever directory we feel appropriate
-        return false;
-    }
-
     private static void releaseAndNullLocks(Lock[] locks) {
         for (int i = 0; i < locks.length; i++) {
             if (locks[i] != null) {

core/src/test/java/org/elasticsearch/env/NodeEnvironmentTests.java

@@ -396,49 +396,6 @@ public class NodeEnvironmentTests extends ESTestCase {
         env.close();
     }
 
-    public void testWhetherClusterFolderShouldBeUsed() throws Exception {
-        Path tempNoCluster = createTempDir();
-        Path tempDataPath = tempNoCluster.toAbsolutePath();
-
-        Path tempPath = tempNoCluster.resolve("foo"); // "foo" is the cluster name
-        Path tempClusterPath = tempPath.toAbsolutePath();
-
-        assertFalse("non-existent directory should not be used", NodeEnvironment.readFromDataPathWithClusterName(tempPath));
-        Settings settings = Settings.builder()
-                .put("cluster.name", "foo")
-                .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath().toString())
-                .put(Environment.PATH_DATA_SETTING.getKey(), tempDataPath.toString()).build();
-        try (NodeEnvironment env = new NodeEnvironment(settings, new Environment(settings))) {
-            Path nodeDataPath = env.nodeDataPaths()[0];
-            assertEquals(nodeDataPath, tempDataPath.resolve("nodes").resolve("0"));
-        }
-        IOUtils.rm(tempNoCluster);
-
-        Files.createDirectories(tempPath);
-        assertFalse("empty directory should not be read from", NodeEnvironment.readFromDataPathWithClusterName(tempPath));
-        settings = Settings.builder()
-                .put("cluster.name", "foo")
-                .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath().toString())
-                .put(Environment.PATH_DATA_SETTING.getKey(), tempDataPath.toString()).build();
-        try (NodeEnvironment env = new NodeEnvironment(settings, new Environment(settings))) {
-            Path nodeDataPath = env.nodeDataPaths()[0];
-            assertEquals(nodeDataPath, tempDataPath.resolve("nodes").resolve("0"));
-        }
-        IOUtils.rm(tempNoCluster);
-
-        // Create a directory for the cluster name
-        Files.createDirectories(tempPath.resolve(NodeEnvironment.NODES_FOLDER));
-        assertTrue("there is data in the directory", NodeEnvironment.readFromDataPathWithClusterName(tempPath));
-        settings = Settings.builder()
-                .put("cluster.name", "foo")
-                .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir().toAbsolutePath().toString())
-                .put(Environment.PATH_DATA_SETTING.getKey(), tempClusterPath.toString()).build();
-        try (NodeEnvironment env = new NodeEnvironment(settings, new Environment(settings))) {
-            Path nodeDataPath = env.nodeDataPaths()[0];
-            assertEquals(nodeDataPath, tempClusterPath.resolve("nodes").resolve("0"));
-        }
-    }
-
     public void testPersistentNodeId() throws IOException {
         String[] paths = tmpPaths();
         NodeEnvironment env = newNodeEnvironment(paths, Settings.builder()

docs/reference/migration/migrate_6_0.asciidoc

@@ -27,6 +27,8 @@ way to reindex old indices is to use the `reindex` API.
 * <<breaking_60_mapping_changes>>
 * <<breaking_60_rest_changes>>
 * <<breaking_60_search_changes>>
+* <<breaking_60_docs_changes>>
+* <<breaking_60_cluster_changes>>
 
 include::migrate_6_0/mapping.asciidoc[]
 
@@ -35,3 +37,5 @@ include::migrate_6_0/rest.asciidoc[]
 include::migrate_6_0/search.asciidoc[]
 
 include::migrate_6_0/docs.asciidoc[]
+
+include::migrate_6_0/cluster.asciidoc[]

docs/reference/migration/migrate_6_0/cluster.asciidoc

@@ -0,0 +1,27 @@
+[[breaking_60_cluster_changes]]
+=== Cluster changes
+
+==== Cluster name no longer allowed in path.data
+
+Previously the cluster name could be used in the `path.data` setting with a
+warning. This is now no longer allowed. For instance, in the previous version
+this was valid:
+
+[source,sh]
+--------------------------------------------------
+# Assuming path.data is /tmp/mydata
+# No longer supported:
+$ tree /tmp/mydata
+/tmp/mydata
+├── <cluster_name>
+│   └── nodes
+│       └── 0
+│           └── <etc>
+
+# Should be changed to:
+$ tree /tmp/mydata
+/tmp/mydata
+├── nodes
+│   └── 0
+│       └── <etc>
+--------------------------------------------------

docs/reference/migration/migrate_6_0/docs.asciidoc

@@ -1,4 +1,4 @@
-[[breaking_60_document_api_changes]]
+[[breaking_60_docs_changes]]
 === Document API changes
 
 ==== version type 'force' removed

modules/percolator/src/test/java/org/elasticsearch/percolator/PercolatorBackwardsCompatibilityTests.java

@@ -143,15 +143,14 @@ public class PercolatorBackwardsCompatibilityTests extends ESIntegTestCase {
     }
 
     private void setupNode() throws Exception {
-        Path dataDir = createTempDir();
-        Path clusterDir = Files.createDirectory(dataDir.resolve(cluster().getClusterName()));
+        Path clusterDir = createTempDir();
         try (InputStream stream = PercolatorBackwardsCompatibilityTests.class.
                 getResourceAsStream("/indices/percolator/bwc_index_2.0.0.zip")) {
             TestUtil.unzip(stream, clusterDir);
         }
 
         Settings.Builder nodeSettings = Settings.builder()
-            .put(Environment.PATH_DATA_SETTING.getKey(), dataDir);
+            .put(Environment.PATH_DATA_SETTING.getKey(), clusterDir);
         internalCluster().startNode(nodeSettings.build());
         ensureGreen(INDEX_NAME);
     }

test/framework/src/main/java/org/elasticsearch/test/ESIntegTestCase.java

@@ -2064,8 +2064,8 @@ public abstract class ESIntegTestCase extends ESTestCase {
             }
             throw new IllegalStateException(builder.toString());
         }
-        Path src = list[0];
-        Path dest = dataDir.resolve(internalCluster().getClusterName());
+        Path src = list[0].resolve(NodeEnvironment.NODES_FOLDER);
+        Path dest = dataDir.resolve(NodeEnvironment.NODES_FOLDER);
         assertTrue(Files.exists(src));
         Files.move(src, dest);
         assertFalse(Files.exists(src));