What is the prefered way to share code between AWS Lambda functions?
I have a structure like this:
This let every function keep its own node_modules and I can package the whole thing with the CLI.
But what about custom code that needs to be shared?
I can require("../mylibrary") but the package command would still not include it.
As dmigo mentioned already it's possible with Lambda layers. Here is some SAM template code for using the Lambda Layer Code:
Globals:
Function:
Runtime: nodejs8.10
MyFunction:
Type: AWS::Serverless::Function
Properties:
CodeUri: a/
Handler: index.handler
Layers:
- !Ref MySharedLayer
MySharedLayer:
Type: AWS::Serverless::LayerVersion
Properties:
LayerName: SharedLayer
Description: Some code to share with the other lambda functions
ContentUri: layer/
CompatibleRuntimes:
- nodejs8.10
RetentionPolicy: Retain
SharedLayer but it doesn't seem to work.Now you can use Layers to share libraries and code between your Functions. You can create a Layer from a zip file the same way you do that for a Function.
The layer package will look more or less like this:
my-layer.zip
└ nodejs/node_modules/mylibrary
If you create your Functions on top of this Layer then in the code it can be referenced like this:
const shared = require('mylibrary');
It is worth noticing that Layers support versioning and relate to Functions as many-to-many. Which makes them second npm.
Try serverless framework, you can use the include/exclude artifacts without having to write your own scripts.
I also use private node packages, but they need to be installed before sls deploy.
The problem with Lambda is, you have to deploy a ZIP-file, so all your code needs to be accesible from one root directory.
I solved this with a script that copies my shared code to all the Lambda-function directories before I archive every single function and upload them.
Symlinks are probably also possible.
serverlessframework?