From d29f817dfd91a4acdbe993383998e92a6e5c21f8 Mon Sep 17 00:00:00 2001
From: Olivier Huin <olivier.huin@bbc.co.uk>
Date: Wed, 28 Oct 2015 15:10:30 +0000
Subject: [PATCH] Adds support for AWS Temporary Credentials

---
 README.md              |  8 ++++++--
 tasks/lambda_deploy.js | 10 ++++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index e1a9b93..0f4fc31 100644
--- a/README.md
+++ b/README.md
@@ -347,6 +347,12 @@ Default value: `null`
 If you wish to use a specific AWS credentials profile you can specify it here, otherwise it will use the environment default.
 You can also specify it with the environment variable `AWS_PROFILE`
 
+##### options.roleArn
+Type: `String`
+Default value: `null`
+
+If you wish to assume a specific role from an EC2 instance you can specify it here, otherwise it will use the environment default.
+
 ##### options.accessKeyId
 Type: `String`
 Default value: `null`
@@ -517,5 +523,3 @@ Adding more warnings for various failure cases
 
 ### 0.10.0
 * Making NPM a regular dependency to resolve [#20](https://github.com/Tim-B/grunt-aws-lambda/issues/20) - [pull request by timdp](https://github.com/Tim-B/grunt-aws-lambda/pull/27)
-
-
diff --git a/tasks/lambda_deploy.js b/tasks/lambda_deploy.js
index 3e79bad..64abebc 100644
--- a/tasks/lambda_deploy.js
+++ b/tasks/lambda_deploy.js
@@ -24,6 +24,7 @@ module.exports = function (grunt) {
 
         var options = this.options({
             profile: null,
+            roleArn: null,
             accessKeyId: null,
             secretAccessKey: null,
             credentialsJSON: null,
@@ -37,6 +38,15 @@ module.exports = function (grunt) {
             AWS.config.credentials = credentials;
         }
 
+        if (options.roleArn !== null) {
+          AWS.config.credentials = new AWS.EC2MetadataCredentials({
+            httpOptions: { timeout: 5000 } // 5 second timeout
+          });
+          AWS.config.credentials = new AWS.TemporaryCredentials({
+            RoleArn: options.roleArn
+          });
+        }
+
         if (options.accessKeyId !== null && options.secretAccessKey !== null) {
           AWS.config.update({accessKeyId: options.accessKeyId, secretAccessKey: options.secretAccessKey});
         }