YARN-6877. Create an abstract log reader for extendability. Contribut…

…ed by Xuan Gong.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/cli/TestLogsCLI.java

@@ -53,6 +53,7 @@
 import java.util.Map;
 import java.util.Set;
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang.StringUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
@@ -468,7 +469,7 @@ public ContainerReport getContainerReport(String containerIdStr)
     assertTrue(exitCode == 0);
     assertTrue(sysOutStream.toString().contains(
         logMessage(containerId1, "syslog")));
-    assertTrue(sysOutStream.toString().contains("Log Upload Time"));
+    assertTrue(sysOutStream.toString().contains("LogLastModifiedTime"));
     assertTrue(!sysOutStream.toString().contains(
       "Logs for container " + containerId1.toString()
           + " are not present in this log-file."));
@@ -492,8 +493,12 @@ public ContainerReport getContainerReport(String containerIdStr)
 
     String logMessage = logMessage(containerId3, "stdout");
     int fileContentSize = logMessage.getBytes().length;
-    int tailContentSize = "\nEnd of LogType:stdout\n\n".getBytes().length;
-
+    StringBuilder sb = new StringBuilder();
+    String endOfFile = "End of LogType:stdout";
+    sb.append("\n" + endOfFile + "\n");
+    sb.append(StringUtils.repeat("*", endOfFile.length() + 50)
+        + "\n\n");
+    int tailContentSize = sb.toString().length();
     // specify how many bytes we should get from logs
     // specify a position number, it would get the first n bytes from
     // container log

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/logaggregation/LogAggregationWebUtils.java

@@ -0,0 +1,124 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.logaggregation;
+
+import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.yarn.api.records.ContainerId;
+import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.webapp.view.HtmlBlock.Block;
+
+/**
+ * Utils for rendering aggregated logs block.
+ *
+ */
+@Private
+public final class LogAggregationWebUtils {
+
+  private LogAggregationWebUtils() {}
+
+  /**
+   * Parse start index from html.
+   * @param html the html
+   * @param startStr the start index string
+   * @return the startIndex
+   */
+  public static long getLogStartIndex(Block html, String startStr)
+      throws NumberFormatException {
+    long start = -4096;
+
+    if (startStr != null && !startStr.isEmpty()) {
+      start = Long.parseLong(startStr);
+    }
+    return start;
+  }
+
+  /**
+   * Parse end index from html.
+   * @param html the html
+   * @param endStr the end index string
+   * @return the endIndex
+   */
+  public static long getLogEndIndex(Block html, String endStr)
+      throws NumberFormatException {
+    long end = Long.MAX_VALUE;
+
+    if (endStr != null && !endStr.isEmpty()) {
+      end = Long.parseLong(endStr);
+    }
+    return end;
+  }
+
+  /**
+   * Verify and parse containerId.
+   * @param html the html
+   * @param containerIdStr the containerId string
+   * @return the {@link ContainerId}
+   */
+  public static ContainerId verifyAndGetContainerId(Block html,
+      String containerIdStr) {
+    if (containerIdStr == null || containerIdStr.isEmpty()) {
+      html.h1().__("Cannot get container logs without a ContainerId").__();
+      return null;
+    }
+    ContainerId containerId = null;
+    try {
+      containerId = ContainerId.fromString(containerIdStr);
+    } catch (IllegalArgumentException e) {
+      html.h1()
+          .__("Cannot get container logs for invalid containerId: "
+              + containerIdStr).__();
+      return null;
+    }
+    return containerId;
+  }
+
+  /**
+   * Verify and parse NodeId.
+   * @param html the html
+   * @param nodeIdStr the nodeId string
+   * @return the {@link NodeId}
+   */
+  public static NodeId verifyAndGetNodeId(Block html, String nodeIdStr) {
+    if (nodeIdStr == null || nodeIdStr.isEmpty()) {
+      html.h1().__("Cannot get container logs without a NodeId").__();
+      return null;
+    }
+    NodeId nodeId = null;
+    try {
+      nodeId = NodeId.fromString(nodeIdStr);
+    } catch (IllegalArgumentException e) {
+      html.h1().__("Cannot get container logs. Invalid nodeId: " + nodeIdStr)
+          .__();
+      return null;
+    }
+    return nodeId;
+  }
+
+  /**
+   * Verify and parse the application owner.
+   * @param html the html
+   * @param appOwner the Application owner
+   * @return the appOwner
+   */
+  public static String verifyAndGetAppOwner(Block html, String appOwner) {
+    if (appOwner == null || appOwner.isEmpty()) {
+      html.h1().__("Cannot get container logs without an app owner").__();
+    }
+    return appOwner;
+  }
+}