From d43e44f8b282a120b4b46fe71182eb030d970b97 Mon Sep 17 00:00:00 2001
From: vmarchaud <contact@vmarchaud.fr>
Date: Tue, 6 Jun 2017 15:57:32 +0200
Subject: [PATCH] (instance_var) allow to overide the key NODE_APP_INSTANCE
 #2045

---
 lib/API/schema.json | 4 ++++
 lib/God.js          | 9 ++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/API/schema.json b/lib/API/schema.json
index a5bb59bd..63a8bc9e 100644
--- a/lib/API/schema.json
+++ b/lib/API/schema.json
@@ -185,5 +185,9 @@
   },
   "increment_var": {
     "type": "string"
+  },
+  "instance_var": {
+    "type": "string",
+    "default" : "NODE_INSTANCE_APP"
   }
 }
diff --git a/lib/God.js b/lib/God.js
index afbc4bf4..dfb9ae5c 100644
--- a/lib/God.js
+++ b/lib/God.js
@@ -457,19 +457,22 @@ God.finalizeProcedure = function finalizeProcedure(proc) {
  * @param {Function} cb invoked with <err, env>
  */
 God.injectVariables = function injectVariables (env, cb) {
+  // allow to override the key of NODE_APP_INSTANCE if wanted
+  var instanceKey = process.env.PM2_PROCESS_INSTANCE_VAR || env.instance_var;
+
   // we need to find the last NODE_APP_INSTANCE used
   var lastInstance = Object.keys(God.clusters_db)
     .map(function (procId) {
       return God.clusters_db[procId];
     }).filter(function (proc) {
       return proc.pm2_env.name === env.name &&
-        typeof proc.pm2_env.NODE_APP_INSTANCE !== 'undefined';
+        typeof proc.pm2_env[instanceKey] !== 'undefined';
     }).map(function (proc) {
-      return proc.pm2_env.NODE_APP_INSTANCE;
+      return proc.pm2_env[instanceKey];
     }).sort(function (a, b) {
       return b - a;
     })[0];
-  env.NODE_APP_INSTANCE = typeof lastInstance === 'undefined' ? 0 : lastInstance + 1;
+  env[instanceKey] = typeof lastInstance === 'undefined' ? 0 : lastInstance + 1;
 
   // if using increment_var, we need to increment it
   if (env.increment_var) {