最新的 Lambda 层 ARN

Question

I have a lambda layer which I keep updating. This lambda layer has multiple versions. How can I find the lambda layer ARN with latest version using aws cli?

Answer 1

I am able to do this using the command listed below -

aws lambda list-layer-versions --layer-name <layer name> --region us-east-1 --query 'LayerVersions[0].LayerVersionArn'

Answer 2

Unfortunately, it's currently not possible (I have encountered the same issue).

You can keep the latest ARN in your own place (like DynamoDB) and update it whenever you publish a new version of the layer.

Answer 3

You can create a custom macro to get the latest lambda layer version and use that as a reference.

The following function gets the latest version from the Lambda Layer stack:

import json
import boto3


def latest_lambdalayer(event, context):
    
    fragment = get_latestversion(event['fragment'])
    return {
      'requestId': event['requestId'],
      'status': 'success',
      'fragment': fragment
    }

def get_latestversion(fragment):
    cloudformation = boto3.resource('cloudformation')
    stack = cloudformation.Stack('ticketapp-layer-dependencies')
    for o in stack.outputs: 
        if o['OutputKey']=='TicketAppLambdaDependency':
            return o['OutputValue']
    #return "arn:aws:lambda:eu-central-1:899885580749:layer:ticketapp-dependencies-layer:16"

And you use this when defining the Lambda layer—here using same global template:

Globals:
  Function:
    Layers:
      - !Transform { "Name" : "LatestLambdaLayer"}
    Runtime: nodejs12.x
    MemorySize: 128
    Timeout: 101