Add collectInfo command

bin/alluxio

@@ -264,6 +264,11 @@ function main {
     ALLUXIO_SHELL_JAVA_OPTS+=" -Dalluxio.conf.validation.enabled=false"
     runJavaClass "$@"
   ;;
+  "collectInfo")
+    CLASS="alluxio.cli.bundler.CollectInfo"
+    CLASSPATH=${ALLUXIO_CLIENT_CLASSPATH}
+    runJavaClass "$@"
+  ;;
   "job")
     CLASS="alluxio.cli.job.JobShell"
     CLASSPATH=${ALLUXIO_CLIENT_CLASSPATH}

core/common/src/main/java/alluxio/cli/CommandUtils.java

@@ -18,10 +18,17 @@
 import org.apache.commons.cli.CommandLine;
 import org.reflections.Reflections;
 
+import java.io.IOException;
 import java.lang.reflect.Modifier;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -104,4 +111,33 @@ public static void checkNumOfArgsNoMoreThan(Command cmd, CommandLine cl, int n)
           .getMessage(cmd.getCommandName(), n, cl.getArgs().length));
     }
   }
+
+  /**
+   * Reads a list of nodes from given file name ignoring comments and empty lines.
+   * Can be used to read conf/workers or conf/masters.
+   * @param confDir directory that holds the configuration
+   * @param fileName name of a file that contains the list of the nodes
+   * @return list of the node names, null when file fails to read
+   */
+  @Nullable
+  public static List<String> readNodeList(String confDir, String fileName) {
+    List<String> lines;
+    try {
+      lines = Files.readAllLines(Paths.get(confDir, fileName), StandardCharsets.UTF_8);
+    } catch (IOException e) {
+      System.err.format("Failed to read file %s/%s. Ignored.", confDir, fileName);
+      return new ArrayList<>();
+    }
+
+    List<String> nodes = new ArrayList<>();
+    for (String line : lines) {
+      String node = line.trim();
+      if (node.startsWith("#") || node.length() == 0) {
+        continue;
+      }
+      nodes.add(node);
+    }
+
+    return nodes;
+  }
 }

core/common/src/main/java/alluxio/shell/CommandReturn.java

@@ -11,11 +11,14 @@
 
 package alluxio.shell;
 
+import java.util.Arrays;
+
 /**
  * Object representation of a command execution.
  */
 public class CommandReturn {
   private int mExitCode;
+  private String[] mCmd;
   private String mOutput;
 
   /**
@@ -26,16 +29,22 @@ public class CommandReturn {
    */
   public CommandReturn(int code, String output) {
     mExitCode = code;
+    mCmd = new String[]{};
     mOutput = output;
   }
 
   /**
-   * Gets the stdout content.
+   * Creates object from the contents.
+   * Copy the command array.
    *
-   * @return stdout content
+   * @param code exit code
+   * @param cmd the command executed
+   * @param output stdout content
    */
-  public String getOutput() {
-    return mOutput;
+  public CommandReturn(int code, String[] cmd, String output) {
+    mExitCode = code;
+    mCmd = Arrays.copyOfRange(cmd, 0, cmd.length);
+    mOutput = output;
   }
 
   /**
@@ -47,14 +56,32 @@ public int getExitCode() {
     return mExitCode;
   }
 
+  /**
+   * Gets the command run.
+   *
+   * @return the command
+   * */
+  public String[] getCmd() {
+    return mCmd;
+  }
+
+  /**
+   * Gets the stdout content.
+   *
+   * @return stdout content
+   */
+  public String getOutput() {
+    return mOutput;
+  }
+
   /**
    * Formats the object to more readable format.
    * This is not done in toString() because stdout and stderr may be long.
    *
    * @return pretty formatted output
    */
   public String getFormattedOutput() {
-    return String.format("StatusCode:%s%nOutput:%n%s", getExitCode(),
-            getOutput());
+    return String.format("ExitCode:%s%nCommand:%s%nOutput:%n%s", getExitCode(),
+            Arrays.toString(getCmd()), getOutput());
   }
 }

core/common/src/main/java/alluxio/shell/ShellCommand.java

@@ -99,15 +99,20 @@ public String run() throws IOException {
   /**
    * Runs a command and returns its output and exit code in Object.
    * Preserves the output when the execution fails.
+   * If the command execution fails (not by an interrupt),
+   * try to wrap the Exception in the {@link CommandReturn}.
    * Stderr is redirected to stdout.
    *
    * @return {@link CommandReturn} object representation of stdout, stderr and exit code
    */
   public CommandReturn runWithOutput() throws IOException {
-    Process process = new ProcessBuilder(mCommand).redirectErrorStream(true).start();
+    Process process = null;
+    BufferedReader inReader = null;
+    try {
+      process = new ProcessBuilder(mCommand).redirectErrorStream(true).start();
+      inReader =
+              new BufferedReader(new InputStreamReader(process.getInputStream()));
 
-    try (BufferedReader inReader =
-                 new BufferedReader(new InputStreamReader(process.getInputStream()))) {
       // read the output of the command
       StringBuilder stdout = new StringBuilder();
       String outLine = inReader.readLine();
@@ -125,7 +130,7 @@ public CommandReturn runWithOutput() throws IOException {
                 exitCode, Arrays.toString(mCommand)));
       }
 
-      CommandReturn cr = new CommandReturn(exitCode, stdout.toString());
+      CommandReturn cr = new CommandReturn(exitCode, mCommand, stdout.toString());
 
       // destroy the process
       if (process != null) {
@@ -136,10 +141,34 @@ public CommandReturn runWithOutput() throws IOException {
     } catch (InterruptedException e) {
       Thread.currentThread().interrupt();
       throw new IOException(e);
+    } catch (Exception e) {
+      return new CommandReturn(1, String.format("Command %s failed, exception is %s",
+              Arrays.toString(mCommand), e.getMessage()));
     } finally {
+      if (inReader != null) {
+        inReader.close();
+      }
       if (process != null) {
         process.destroy();
       }
     }
   }
+
+  /**
+   * Converts the command to string repr.
+   *
+   * @return the shell command
+   * */
+  public String toString() {
+    return Arrays.toString(mCommand);
+  }
+
+  /**
+   * Gets the command. The original array is immutable.
+   *
+   * @return a copy of the command string array
+   * */
+  public String[] getCommand() {
+    return Arrays.copyOfRange(mCommand, 0, mCommand.length);
+  }
 }

core/common/src/main/java/alluxio/util/ShellUtils.java

@@ -240,5 +240,23 @@ public static CommandReturn scpCommandWithOutput(
     return new ScpCommand(hostname, fromFile, toFile, isDir).runWithOutput();
   }
 
+  /**
+   * Executes a shell command.
+   * If it fails, try the backup command.
+   *
+   * @param cmd the primary command
+   * @param backupCmd a backup option
+   * @return the {@link CommandReturn} with combined output
+   */
+  public static CommandReturn execCmdWithBackup(ShellCommand cmd, ShellCommand backupCmd)
+          throws IOException {
+    CommandReturn cr = cmd.runWithOutput();
+    // If the command works or there is no backup option, return
+    if (cr.getExitCode() == 0 || backupCmd == null) {
+      return cr;
+    }
+    return backupCmd.runWithOutput();
+  }
+
   private ShellUtils() {} // prevent instantiation
 }

core/common/src/test/java/alluxio/shell/ShellCommandTest.java

@@ -93,13 +93,13 @@ public void execCommandTolerateFailureFailed() throws Exception {
   public void execCommandTolerateFailureInvalidCommand() throws Exception {
     // create temp file
     File testDir = AlluxioTestDirectory.createTemporaryDirectory("command");
-
-    // if there's no such command there will be IOException
-    mExceptionRule.expect(IOException.class);
-    mExceptionRule.expectMessage("No such file or directory");
+    // For a non-existent command the command return contains the err msg
     String[] testCommandExcept = new String[]{"lsa",
             String.format("%s", testDir.getAbsolutePath())};
     // lsa is not a valid executable
-    new ShellCommand(testCommandExcept).runWithOutput();
+    CommandReturn crf = new ShellCommand(testCommandExcept).runWithOutput();
+    System.out.println(crf.getFormattedOutput());
+    assertNotEquals(0, crf.getExitCode());
+    assertTrue(crf.getOutput().contains("No such file or directory"));
   }
 }

core/server/common/src/main/java/alluxio/cli/validation/Utils.java

@@ -11,6 +11,7 @@
 
 package alluxio.cli.validation;
 
+import alluxio.cli.CommandUtils;
 import alluxio.conf.ServerConfiguration;
 import alluxio.conf.PropertyKey;
 import alluxio.util.ShellUtils;
@@ -22,10 +23,6 @@
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.Socket;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Paths;
-import java.util.ArrayList;
 import java.util.List;
 
 import javax.annotation.Nullable;
@@ -83,24 +80,7 @@ public static boolean isAlluxioRunning(String className) {
   @Nullable
   public static List<String> readNodeList(String fileName) {
     String confDir = ServerConfiguration.get(PropertyKey.CONF_DIR);
-    List<String> lines;
-    try {
-      lines = Files.readAllLines(Paths.get(confDir, fileName), StandardCharsets.UTF_8);
-    } catch (IOException e) {
-      System.err.format("Failed to read file %s/%s.%n", confDir, fileName);
-      return null;
-    }
-
-    List<String> nodes = new ArrayList<>();
-    for (String line : lines) {
-      String node = line.trim();
-      if (node.startsWith("#") || node.length() == 0) {
-        continue;
-      }
-      nodes.add(node);
-    }
-
-    return nodes;
+    return CommandUtils.readNodeList(confDir, fileName);
   }
 
   /**

shell/pom.xml

@@ -81,5 +81,9 @@
       <artifactId>alluxio-job-client</artifactId>
       <version>${project.version}</version>
     </dependency>
+      <dependency>
+          <groupId>org.apache.commons</groupId>
+          <artifactId>commons-compress</artifactId>
+      </dependency>
   </dependencies>
 </project>