From c7cec7bb2912ecebb98f72a7e3f5f49d49303baa Mon Sep 17 00:00:00 2001
From: Unitech <alexandre@keymetrics.io>
Date: Tue, 22 Oct 2019 12:44:29 +0200
Subject: [PATCH] feature: enable sysinfos + safeguard via ping/pong

---
 lib/Daemon.js             |  4 +--
 lib/God.js                | 26 +++++++-------
 lib/Sysinfo/SystemInfo.js | 72 +++++++++++++++++++++++++++++++++------
 package.json              |  2 +-
 4 files changed, 78 insertions(+), 26 deletions(-)

diff --git a/lib/Daemon.js b/lib/Daemon.js
index b9e10935..7a120586 100644
--- a/lib/Daemon.js
+++ b/lib/Daemon.js
@@ -259,7 +259,7 @@ Daemon.prototype.close = function(opts, cb) {
     msg    : 'pm2 has been killed via CLI'
   });
 
-  if (God.system_infos !== null)
+  if (God.system_infos_proc !== null)
     God.system_infos_proc.kill()
 
   /**
@@ -336,7 +336,7 @@ Daemon.prototype.gracefullExit = function() {
 
   console.log('pm2 has been killed by signal, dumping process list before exit...');
 
-  if (God.system_infos !== null)
+  if (God.system_infos_proc !== null)
     God.system_infos_proc.kill()
 
   God.dumpProcessList(function() {
diff --git a/lib/God.js b/lib/God.js
index ed0ab7b1..7e9881d8 100644
--- a/lib/God.js
+++ b/lib/God.js
@@ -75,21 +75,21 @@ God.init = function() {
 
   God.system_infos_proc = null
 
-  // try {
-  //   var sysinfo = require('./Sysinfo/SystemInfo.js')
-  //   God.system_infos_proc = new sysinfo()
+  try {
+    var sysinfo = require('./Sysinfo/SystemInfo.js')
+    God.system_infos_proc = new sysinfo()
 
-  //   setInterval(() => {
-  //     God.system_infos_proc.query((err, data) => {
-  //       God.system_infos = data
-  //     })
-  //   }, 1000)
+    setInterval(() => {
+      God.system_infos_proc.query((err, data) => {
+        God.system_infos = data
+      })
+    }, 1000)
 
-  //   God.system_infos_proc.fork()
-  // } catch(e) {
-  //   console.log(e)
-  //   God.system_infos_proc = null
-  // }
+    God.system_infos_proc.fork()
+  } catch(e) {
+    console.log(e)
+    God.system_infos_proc = null
+  }
 }
 
 God.writeExitSeparator = function(pm2_env, code, signal) {
diff --git a/lib/Sysinfo/SystemInfo.js b/lib/Sysinfo/SystemInfo.js
index 1bc2a0c5..f7f4dada 100644
--- a/lib/Sysinfo/SystemInfo.js
+++ b/lib/Sysinfo/SystemInfo.js
@@ -79,6 +79,7 @@ class SystemInfo {
       }
     }
     this.restart = true
+    this.ping_timeout = null
   }
 
   // Cast MeanCalc and other object to real value
@@ -106,29 +107,53 @@ class SystemInfo {
 
     this.process.on('exit', (code) => {
       console.log(`systeminfos collection process offline with code ${code}`)
-      if (this.restart == true)
-        this.fork()
+      // if (this.restart == true)
+      //   this.fork()
     })
 
     this.process.on('error', (e) => {
       console.log(`Sysinfo errored`, e)
     })
+
+    this.process.on('message', (msg) => {
+      try {
+        msg = JSON.parse(msg)
+      }
+      catch (e) {
+      }
+      if (msg.cmd == 'ping') {
+        if (this.process.connected == true) {
+          try {
+            this.process.send('pong')
+          } catch(e) {
+            console.error('Cannot send message to Sysinfos')
+          }
+        }
+      }
+    })
   }
 
   query(cb) {
     this.process.send('query')
-    this.process.once('message', (data) => {
+    var res = (msg) => {
       try {
-        data = JSON.parse(data)
+        msg = JSON.parse(msg)
       }
       catch (e) {
       }
-      return cb(null, data)
-    })
+
+      if (msg.cmd == 'query:res') {
+        listener.removeListener('message', res)
+        return cb(null, msg.data)
+      }
+    }
+
+    var listener = this.process.on('message', res)
   }
 
   kill() {
     this.restart = false
+    console.log('>>>>>>>>>>>>>>>>>>>>>>>> SYSTEMINFO EXITED')
     this.process.kill()
   }
 
@@ -162,11 +187,38 @@ class SystemInfo {
     this.cpuStatsWorker()
     this.fdStatsWorker()
 
-    process.on('message', (data) => {
-      if (data == 'query') {
+    setInterval(() => {
+      if (process.connected == false) {
+        console.error('Sysinfos not connected, exiting')
+        process.exit()
+      }
+      try {
+        process.send(JSON.stringify({cmd: 'ping'}))
+      } catch(e) {
+        console.error('PM2 is dead while doing process.send')
+        process.exit()
+      }
+      this.ping_timeout = setTimeout(() => {
+        console.error('PM2 is dead while waiting for a pong')
+        process.exit()
+      }, 500)
+    }, 1000)
+
+    // Systeminfo receive command
+    process.on('message', (cmd) => {
+      if (cmd == 'query') {
         try {
-          process.send(JSON.stringify(this.report()))
-        } catch (e) {}
+          var res = JSON.stringify({
+            cmd: 'query:res',
+            data: this.report()
+          })
+          process.send(res)
+        } catch (e) {
+          console.error('Could not retrieve system informations', e)
+        }
+      }
+      else if (cmd == 'pong') {
+        clearTimeout(this.ping_timeout)
       }
     })
 
diff --git a/package.json b/package.json
index 4b5f61ac..4d381f67 100644
--- a/package.json
+++ b/package.json
@@ -200,7 +200,7 @@
     "should": "^13"
   },
   "optionalDependencies": {
-    "systeminformation": "^4.14.11"
+    "systeminformation": "^4.14.16"
   },
   "bugs": {
     "url": "https://github.com/Unitech/pm2/issues"