From 01d9affe61efbf35fdeb304985dfc5061d24299e Mon Sep 17 00:00:00 2001
From: cow0w <ohad.peleg@gmail.com>
Date: Fri, 17 Jun 2022 22:18:14 +0300
Subject: [PATCH] Add support for evalulating {{env.<var>}} within a template
 node

---
 .../nodes/core/function/80-template.js        | 24 +++++++++++++++++++
 test/nodes/core/function/80-template_spec.js  | 22 +++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/packages/node_modules/@node-red/nodes/core/function/80-template.js b/packages/node_modules/@node-red/nodes/core/function/80-template.js
index d4c27cfd0..69954aba2 100644
--- a/packages/node_modules/@node-red/nodes/core/function/80-template.js
+++ b/packages/node_modules/@node-red/nodes/core/function/80-template.js
@@ -44,6 +44,14 @@ module.exports = function(RED) {
         return undefined;
     }
 
+    function parseEnv(key) {
+        var match = /^env\.(.+)/.exec(key);
+        if (match) {
+            return match[1];
+        }
+        return undefined;
+    }
+
     /**
      * Custom Mustache Context capable to collect message property and node
      * flow and global context
@@ -74,6 +82,11 @@ module.exports = function(RED) {
                 return value;
             }
 
+            // try env
+            if (parseEnv(name)) {
+                return this.cachedContextTokens[name];
+            }
+
             // try flow/global context:
             var context = parseContext(name);
             if (context) {
@@ -156,6 +169,17 @@ module.exports = function(RED) {
                     var tokens = extractTokens(mustache.parse(template));
                     var resolvedTokens = {};
                     tokens.forEach(function(name) {
+                        var env_name = parseEnv(name);
+                        if (env_name) {
+                            var promise = new Promise((resolve, reject) => {
+                                var val = RED.util.evaluateNodeProperty(env_name, 'env', node)
+                                resolvedTokens[name] = val;
+                                resolve();
+                            });
+                            promises.push(promise);
+                            return;
+                        }
+
                         var context = parseContext(name);
                         if (context) {
                             var type = context.type;
diff --git a/test/nodes/core/function/80-template_spec.js b/test/nodes/core/function/80-template_spec.js
index e944824b3..b4f530d05 100644
--- a/test/nodes/core/function/80-template_spec.js
+++ b/test/nodes/core/function/80-template_spec.js
@@ -144,6 +144,28 @@ describe('template node', function() {
         });
     });
 
+    describe('env var', function() {
+        before(function() {
+            process.env.TEST = 'xyzzy';
+        })
+        after(function() {
+            delete process.env.TEST;
+        })
+
+        it('should modify payload from env variable', function(done) {
+            var flow = [{id:"n1",z:"t1", type:"template", field:"payload", template:"payload={{env.TEST}}",wires:[["n2"]]},{id:"n2",z:"t1",type:"helper"}];
+            helper.load(templateNode, flow, function() {
+                var n1 = helper.getNode("n1");
+                var n2 = helper.getNode("n2");
+                n2.on("input", function(msg) {
+                    msg.should.have.property('payload', 'payload=xyzzy');
+                    done();
+                });
+                n1.receive({payload:"foo",topic: "bar"});
+            });
+        });
+    });
+
     it('should modify payload from flow context', function(done) {
         var flow = [{id:"n1",z:"t1", type:"template", field:"payload", template:"payload={{flow.value}}",wires:[["n2"]]},{id:"n2",z:"t1",type:"helper"}];
         helper.load(templateNode, flow, function() {