I have a serverless application that uses CDK. I want to add a lambda layer to share some functionality across different areas of the application.
I define the layer in a CDK stack using
const encryptLayer = new lambda.LayerVersion(this, 'encrypt-layer', {
compatibleRuntimes: [
lambda.Runtime.NODEJS_14_X,
],
code: lambda.Code.fromAsset(path.join(__dirname,'src/Layers/EncryptDecryptFunctions')),
description: 'shared functions to encrypt/decrypt data using asymmetric key'
});
and I added encryptLayer to a few of the functions in the same stack using the layers attribute when calling new lambda.Function().... I deployed this and I see the layer sitting under the correct function in the console.
The file structure for the layer is
src
Layers
EncryptFunctions
nodejs
encrypt.js
package.json
and I am trying to import it using
const { encrypt } = require("/opt/nodejs/encrypt") per the AWS documentation. However, I am getting a module not found exception when running the lambda that uses the encrypt method.
Is there anything else I need to do so that I can use the layer's code in my lambdas? For both code in the same repository and in a different repository?
This seems an issue of PATH. As shown in this doc, paths for each Lambda runtime of Node.js are:
nodejs/node_modulesnodejs/node14/node_modules (NODE_PATH)Therefore, you can add node_modules/ direcitory. Use nodejs/node_modules/ instead of nodejs in the file structure.
And import in lambda code will be like:
const encrypt = require('encrypt')
The issue here is that I was bundling my lambdas using webpack and I didn't add '/opt/nodejs/encrypt' to my externals in webpack config. Doing that fixed my problem.
You can use a serverless framework where you can define all in yml file like the below code.
layers:
AnalyticsShared:
path: node_modules
name: analytics-shared-${opt:stage, self:provider.stage}
description: "Shared node modules for analytics"
functions:
track:
handler: analytics.queue
timeout: 30
layers:
- {Ref: AnalyticsSharedLambdaLayer}
Ref URLs: https://www.serverless.com/framework/docs/providers/aws/guide/layers