Fogbugz 3426: Kill and restart the process in pm2 (#88)

* Fogbugz 3426: Kill and restart the process in pm2

* Remove console log's

pm2.js

@@ -1,5 +1,7 @@
 const pm2 = require('pm2');
 const fs = require('fs');
+const COMPILER = "eosio compiler";
+const EXPLORER = "eosio explorer";
 
 const displayStatus = (app) => {
     if (app.pm2_env.status === "online") {
@@ -11,16 +13,11 @@ const displayStatus = (app) => {
     }
 }
 
-pm2.connect(function(err) {
-  if (err) {
-    console.error(err);
-    process.exit(2);
-  }
-
+const startPm2 = () =>{
   console.log("\x1b[36mstarting app and compiler using pm2\x1b[0m");
   if (fs.existsSync(process.argv.slice(2)[0])) {
     pm2.start({
-      name      : "eosio compiler",
+      name      : COMPILER,
       script    : 'yarn start',
       cwd: process.argv.slice(2)[0]
     }, function(err, app) {
@@ -32,10 +29,52 @@ pm2.connect(function(err) {
     console.log ("\x1b[31merror finding compiler path\x1b[0m");
 
   pm2.start({
-    name      : "eosio explorer",
+    name      : EXPLORER,
     script    : 'serve.js'         // Script to be run
   }, function(err, app) {
     if (err) throw err
     displayStatus(app[0]);
   });
+}
+
+const deletePm2 = (list) =>{
+  let delete_count = 0;
+  list.forEach((app) =>{
+    pm2.delete(app.pm2_env.pm_id, (err, res)=> {
+      delete_count++;
+      if(delete_count === list.length){
+        startPm2();
+      }
+    });
+  });
+}
+
+pm2.connect(function(err) {
+  if (err) {
+    console.error(err);
+    process.exit(2);
+  }
+  // clearing the already running pm2 instances before starting
+  pm2.list((err, apps)=>{
+    if(err)
+      console.log("error encountered while fetching pm2 list-> ", err);
+    else { 
+      if(apps.length > 0){
+        let deleteList = [];
+        apps.forEach((app, index)=>{          
+          if(app.pm2_env.name === EXPLORER || app.pm2_env.name === COMPILER){
+            deleteList.push(app); 
+          }
+          if(index === apps.length-1){
+            if(deleteList.length > 0)
+              deletePm2(deleteList);
+            else
+              startPm2();              
+          }              
+        });           
+      }else{
+        startPm2();
+      }         
+    }
+  });
 });