Add the ability to set KMSKeyArn to a Lambda function

[deekthesqueak]

The AWS SDK has the ability to set the KMSKeyArn when creating a Lambda function.
https://docs.aws.amazon.com/lambda/latest/dg/API_CreateFunction.html

This PR adds the ability to set the KMSKeyArn. By default the value is not included in the params.

[deekthesqueak]

I wasn't sure if I should include a conditional check here or not to add KMSKeyArn to the params.

[deekthesqueak]

This is a possible way to conditionally add it:

diff --git a/lib/main.js b/lib/main.js
index 3f5735e..9791c7e 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -466,7 +466,7 @@ Lambda.prototype._uploadExisting = (lambda, params) => {
     }, (err) => {
       if (err) return reject(err)

-      lambda.updateFunctionConfiguration({
+      lambda.updateFunctionConfiguration(Object.assign({
         'FunctionName': params.FunctionName,
         'Description': params.Description,
         'Handler': params.Handler,
@@ -476,10 +476,10 @@ Lambda.prototype._uploadExisting = (lambda, params) => {
         'Runtime': params.Runtime,
         'VpcConfig': params.VpcConfig,
         'Environment': params.Environment,
-        'KMSKeyArn': params.KMSKeyArn,
         'DeadLetterConfig': params.DeadLetterConfig,
         'TracingConfig': params.TracingConfig
-      }, (err, data) => {
+      }, (typeof params.KMSKeyArn !== undefined) ? {'KMSKeyArn': params.KMSKeyArn}: {}),
+      (err, data) => {
         if (err) return reject(err)
         resolve(data)
       })

[DeviaVir]

Hmm, the only way to find that out is to test it. Sometimes the AWS SDK makes a problem from passing undefined parameters. I think the way your patch does it is the "safe" way and I would recommend updating it to that.

[deekthesqueak]

KMSKeyArn will only clear with an empty string. If left undefined no change will be processed. With this change not including the environment variable will clear it.

There isn't a need to conditionally add it.

[DeviaVir]

👍 thanks for taking to time to add this!

[joshwiens]

@DeviaVir - Any chance you could tag / publish a minor off of master, we could of course run off a hash from git but in this case the addition above is going straight to prod & I would prefer to not have to go the git repo route as a version in a prod app. Thanks :)

[DeviaVir]

@d3viant0ne yep, I'll publish a tag today.

[DeviaVir]

@d3viant0ne https://www.npmjs.com/package/node-lambda 0.11.4 now available.