From ff3e38552e27dcb8c13b652e68f76ed1d1667be1 Mon Sep 17 00:00:00 2001
From: Ersel Aker <erselaker@gmail.com>
Date: Sat, 13 Aug 2016 20:25:31 +0100
Subject: [PATCH] allow injection of environment variables via config file at
 runtime

---
 README.md       |  1 +
 bin/node-lambda |  2 ++
 lib/main.js     | 18 ++++++++++++++++++
 test/main.js    | 23 +++++++++++++++++++++++
 4 files changed, 44 insertions(+)

diff --git a/README.md b/README.md
index 81ef4a47..c898425f 100644
--- a/README.md
+++ b/README.md
@@ -68,6 +68,7 @@ $ node-lambda run --help
     -h, --help                          Output usage information
     --handler [index.handler]           Lambda Handler {index.handler}
     -j, --eventFile [event.json]        Event JSON File
+    -f, --configFile []                 Path to file holding secret environment variables (e.g. "deploy.env")
     -u, --runtime [nodejs4.3]           Lambda Runtime {nodejs4.3, nodejs} - "nodejs4.3" is the current standard, "nodejs" is v0.10.36
     -x, --contextFile [context.json]    Context JSON file
 ```
diff --git a/bin/node-lambda b/bin/node-lambda
index dcb3ca2c..ae68e04a 100755
--- a/bin/node-lambda
+++ b/bin/node-lambda
@@ -92,6 +92,8 @@ program
   .option('--handler [' + AWS_HANDLER + ']', 'Lambda Handler {index.handler}', AWS_HANDLER)
   .option('-j, --eventFile [' + EVENT_FILE + ']', 'Event JSON File', EVENT_FILE)
   .option('-u, --runtime [' + AWS_RUNTIME + ']', 'Lambda Runtime', AWS_RUNTIME)
+  .option('-f, --configFile [' + CONFIG_FILE + ']',
+    'Path to file holding secret environment variables (e.g. "deploy.env")', CONFIG_FILE)
   .option('-x, --contextFile [' + CONTEXT_FILE + ']', 'Context JSON File', CONTEXT_FILE)
   .action(function (prg) {
     lambda.run(prg);
diff --git a/lib/main.js b/lib/main.js
index 3ecc43b1..d1b5b8e9 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -46,6 +46,11 @@ Lambda.prototype.run = function (program) {
   var event = require(process.cwd() + '/' + program.eventFile);
   var context = require(process.cwd() + '/' + program.contextFile);
 
+  // Set custom environment variables if program.configFile is defined
+  if (program.configFile) {
+    this._setRunTimeEnvironmentVars(program);
+  }
+
   this._runHandler(handler, event, program.runtime, context);
 };
 
@@ -300,6 +305,19 @@ Lambda.prototype._setEnvironmentVars = function (program, codeDirectory) {
   fs.writeFileSync(handlerFileName, contentStr);
 };
 
+Lambda.prototype._setRunTimeEnvironmentVars = function (program) {
+  var configValues = fs.readFileSync(program.configFile);
+  var config = dotenv.parse(configValues);
+
+  for (var k in config) {
+    if (!config.hasOwnProperty(k)) {
+      continue;
+    }
+
+    process.env[k]=config[k];
+  }
+};
+
 Lambda.prototype._uploadExisting = function(lambda, params, cb) {
   return lambda.updateFunctionCode({
     'FunctionName': params.FunctionName,
diff --git a/test/main.js b/test/main.js
index 99238ef2..2bef2e68 100644
--- a/test/main.js
+++ b/test/main.js
@@ -276,6 +276,29 @@ describe('node-lambda', function () {
 
   });
 
+  describe('environment variable injection at runtime', function () {
+    beforeEach(function () {
+      // Prep...
+      fs.writeFileSync('tmp.env', 'FOO=bar\nBAZ=bing\n');
+    });
+
+    afterEach(function () {
+      fs.unlinkSync('tmp.env');
+    });
+
+    it('should inject environment variables at runtime', function () {
+
+      // Run it...
+      lambda._setRunTimeEnvironmentVars({
+        configFile: 'tmp.env'
+      }, process.cwd());
+
+      assert.equal(process.env["FOO"], 'bar');
+      assert.equal(process.env["BAZ"], 'bing');
+    });
+
+  });
+
   describe('environment variable injection - "use strict" allowance', function () {
     beforeEach(function () {
       // Prep...