Support globally installed scripts as post_start_hook

Author: dreusel

lib/God.js

@@ -25,6 +25,7 @@ var Utility       = require('./Utility');
 var cst           = require('../constants.js');
 var timesLimit    = require('async/timesLimit');
 var Configuration = require('./Configuration.js');
+var which         = require('./tools/which');
 
 /**
  * Override cluster module configuration
@@ -215,8 +216,24 @@ God.executeApp = function executeApp(env, cb) {
   var appRunningCb = function(clu) {
     var post_start_hook = env_copy['post_start_hook'];
     if (post_start_hook) {
+      // Full path script resolution
+      var hook_path = path.resolve(clu.pm2_env.cwd, post_start_hook);
+
+      // If script does not exist after resolution
+      if (!fs.existsSync(hook_path)) {
+        var ckd;
+        // Try resolve command available in $PATH
+        if ((ckd = which(post_start_hook))) {
+          if (typeof(ckd) !== 'string')
+            ckd = ckd.toString();
+          hook_path = ckd;
+        }
+        else
+            // Throw critical error
+          return new Error(`post_start_hook not found: ${post_start_hook}`);
+      }
       try {
-        var hookFn = require(post_start_hook);
+        var hookFn = require(hook_path);
         if (typeof hookFn !== 'function') {
           throw new Error('post_start_hook module.exports must be a function');
         }