feature: add inspect feature, on runtime

bin/pm2

@@ -396,6 +396,13 @@ commander.command('id <name>')
     pm2.getProcessIdByName(name);
   });
 
+// Inspect a process
+commander.command('inspect <name>')
+  .description('inspect a process')
+  .action(function(cmd) {
+    pm2.inspect(cmd, commander);
+  });
+
 //
 // Stop and delete a process by name from database
 //

lib/API/Extra.js

@@ -15,6 +15,7 @@ var fs          = require('fs');
 var fmt         = require('../tools/fmt.js');
 var moment      = require('moment');
 var pkg         = require('../../package.json');
+const semver    = require('semver');
 
 module.exports = function(CLI) {
 
@@ -38,7 +39,6 @@ module.exports = function(CLI) {
    */
   CLI.prototype.report = function() {
     var that = this;
-    var semver = require('semver');
 
     function reporting(cb) {
 
@@ -639,4 +639,22 @@ module.exports = function(CLI) {
 
     launchMonitor();
   };
+
+  CLI.prototype.inspect = function(app_name, cb) {
+    const that = this;
+    if(semver.satisfies(process.versions.node, '>= 8.0.0')) {
+      this.trigger(app_name, 'internal:inspect', function (err, res) {
+        if(res[0].data.return === '') {
+          Common.printOut(`Inspect disabled on ${app_name}`);
+        } else {
+          Common.printOut(`Inspect enabled on ${app_name} => go to chrome : chrome://inspect !!!`);
+        }
+
+        that.exitCli(cst.SUCCESS_EXIT);
+      });
+    } else {
+      Common.printOut('Inspect is available for node version >=8.x !');
+      that.exitCli(cst.SUCCESS_EXIT);
+    }
+  };
 };

lib/ProcessContainerFork.js

@@ -1,17 +1,33 @@
-/**
+  /**
  * Copyright 2013 the PM2 project authors. All rights reserved.
  * Use of this source code is governed by a license that
  * can be found in the LICENSE file.
  */
 // Inject custom modules
 if (process.env.pmx !== 'false') {
-  require('pmx').init({
+  const pmx = require('pmx');
+  pmx.init({
     transactions: (process.env.km_link === 'true' && (process.env.trace === 'true' || process.env.deep_monitoring === 'true')) || false,
     http: process.env.km_link === 'true' || false,
     v8: process.env.v8 === 'true' || process.env.deep_monitoring === 'true' || false,
     event_loop_dump: process.env.event_loop_inspector === 'true' || process.env.deep_monitoring === 'true' || false,
     deep_metrics: process.env.deep_monitoring === 'true' || false
   });
+
+  if(require('semver').satisfies(process.versions.node, '>= 8.0.0')) {
+    var url = '';
+    pmx.action('internal:inspect', function(reply) {
+      const inspector = require('inspector');
+      if(url === '') {
+        inspector.open();
+        url = inspector.url();
+      } else {
+        inspector.close();
+        url = '';
+      }
+      reply(url);
+    });
+  }
 }
 
 if (typeof(process.env.source_map_support) != "undefined" &&