Improve collectInfo command

Various improvements to `collectInfo` command:
1. scp now doesn't hardcode "localhost". Specifying `localhost` works on
Mac but not on a CentOS machine.
2. If the command is invalid like `alluxio collectInfo bar /dir`, early
reject before distributing the command and find out it's invalid
locally.
3. Catch metrics collection errors when metrics are unavailable, instead
of failing the command and subsequently skips collecting tarballs.
4. Misc bash command fixes.

pr-link: #10918
change-id: cid-3e4f7ed784d28bd0dafd52a92bb4ac7a417a7275

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

@@ -44,7 +44,7 @@ public ScpCommand(String remoteHost, String fromFile, String toFile) {
    */
   public ScpCommand(String remoteHost, String fromFile, String toFile, boolean isDir) {
     super(new String[]{"bash", "-c",
-            String.format(isDir ? "scp -r %s %s:%s localhost:%s" : "scp %s %s:%s localhost:%s",
+            String.format(isDir ? "scp -r %s %s:%s %s" : "scp %s %s:%s %s",
                     ShellUtils.COMMON_SSH_OPTS, remoteHost, fromFile, toFile)
     });
     mHostName = remoteHost;

shell/src/main/java/alluxio/cli/bundler/CollectInfo.java

@@ -146,6 +146,10 @@ public static void main(String[] argv) throws IOException {
               2, argv.length);
       shell.printUsage();
       System.exit(-1);
+    } else if (shell.findCommand(args[0]) == null) {
+      System.out.format("Command %s is not recognized.%n", args[0]);
+      shell.printUsage();
+      System.exit(-2);
     }
 
     // Choose mode based on option

shell/src/main/java/alluxio/cli/bundler/command/CollectEnvCommand.java

@@ -38,33 +38,33 @@ public CollectEnvCommand(FileSystemContext fsContext) {
   @Override
   protected void registerCommands() {
     registerCommand("Alluxio ps",
-            new ShellCommand(new String[]{"bash", "-c", "'ps -ef | grep alluxio'"}), null);
+            new ShellCommand(new String[]{"bash", "-c", "ps", "-ef", "| grep alluxio"}), null);
     registerCommand("Spark ps",
-            new ShellCommand(new String[]{"bash", "-c", "'ps -ef | grep spark'"}), null);
+            new ShellCommand(new String[]{"bash", "-c", "ps", "-ef", "| grep spark"}), null);
     registerCommand("Yarn ps",
-            new ShellCommand(new String[]{"bash", "-c", "'ps -ef | grep yarn'"}), null);
+            new ShellCommand(new String[]{"bash", "-c", "ps", "-ef", "| grep yarn"}), null);
     registerCommand("Hdfs ps",
-            new ShellCommand(new String[]{"bash", "-c", "'ps -ef | grep hdfs'"}), null);
+            new ShellCommand(new String[]{"bash", "-c", "ps", "-ef", "| grep hdfs"}), null);
     registerCommand("Presto ps",
-            new ShellCommand(new String[]{"bash", "-c", "'ps -ef | grep presto'"}), null);
+            new ShellCommand(new String[]{"bash", "-c", "ps", "-ef", "| grep presto"}), null);
     registerCommand("env",
             new ShellCommand(new String[]{"env"}), null);
     registerCommand("top", new ShellCommand(new String[]{"atop", "-b", "-n", "1"}),
             new ShellCommand(new String[]{"top", "-b", "-n", "1"}));
     registerCommand("mount", new ShellCommand(new String[]{"mount"}), null);
     registerCommand("df", new ShellCommand(new String[]{"df", "-H"}), null);
-    registerCommand("ulimit", new ShellCommand(new String[]{"ulimit -Ha"}), null);
+    registerCommand("ulimit", new ShellCommand(new String[]{"ulimit", "-Ha"}), null);
     registerCommand("uname", new ShellCommand(new String[]{"uname", "-a"}), null);
     registerCommand("hostname", new ShellCommand(new String[]{"hostname"}), null);
     registerCommand("host ip", new ShellCommand(new String[]{"hostname", "-i"}), null);
     registerCommand("host fqdn", new ShellCommand(new String[]{"hostname", "-f"}), null);
     registerCommand("list Alluxio home",
-            new ShellCommand(new String[]{String.format("ls -al -R %s",
+            new ShellCommand(new String[]{String.format("ls", "-al -R %s",
                     mFsContext.getClusterConf().get(PropertyKey.HOME))}), null);
-    registerCommand("dig", new ShellCommand(new String[]{"dig $(hostname -i)"}), null);
+    registerCommand("dig", new ShellCommand(new String[]{"dig", "$(hostname -i)"}), null);
     registerCommand("nslookup", new ShellCommand(new String[]{"nslookup", "$(hostname -i)"}), null);
-    // TODO(jiacheng): does this stop?
-    registerCommand("dstat", new ShellCommand(new String[]{"dstat", "-cdgilmnprsty"}), null);
+    registerCommand("dstat", new ShellCommand(
+            new String[]{"dstat", "-cdgilmnprsty", "1", "5"}), null);
   }
 
   @Override

shell/src/main/java/alluxio/cli/bundler/command/CollectMetricsCommand.java

@@ -88,7 +88,15 @@ public int run(CommandLine cl) throws AlluxioException, IOException {
       LOG.info(String.format("Metric address URL: %s", url));
 
       // Get metrics
-      String metricsResponse = getMetricsJson(url);
+      String metricsResponse;
+      try {
+        metricsResponse = getMetricsJson(url);
+      } catch (Exception e) {
+        // Do not break the loop since the HTTP failure can be due to many reasons
+        // Return the error message instead
+        LOG.error("Failed to get Alluxio metrics from URL %s. Exception is %s", url, e);
+        metricsResponse =  String.format("Url: %s%nError: %s", url, e.getMessage());
+      }
       outputBuffer.write(metricsResponse);
 
       // Write to file
@@ -120,6 +128,8 @@ public String getDescription() {
 
   /**
    * Probes Alluxio metrics json sink.
+   * If the HTTP request fails, return the error content
+   * instead of throwing an exception.
    *
    * @param url URL that serves Alluxio metrics
    * @return HTTP response in JSON string