Using the alb event to add an alb trigger to lambda

Serverless Framework
1

We’re trying to automatically add an alb trigger to one of our lambda functions. I’ve looked at this doc (https://www.serverless.com/framework/docs/providers/aws/events/alb/) as well as the source code for the serverless alb event, but haven’t managed to get things working. My understanding is that the alb event adds a rule to a preexisting alb and also creates the target group to be linked with the lambda. If I’m misunderstanding this please let me know, any advice is appreciated. In addition to this, it looks like only one http header value is expected. Our current rule checks multiple http headers and I wanted to confirm that I’m unable to do that with this alb event.
Here is my serverless.yml.

service:
  name: pe

plugins:  
  - serverless-pseudo-parameters

package:
  exclude:
    - ".*/local/**"
  
provider:
  name: aws  
  runtime: nodejs12.x
  region: ${opt:region}
  role: ${opt:lambdaRole}
  deploymentBucket: ${opt:deploymentBucket}

functions:
  queueEmailStatus:
    handler: lambdas/queueEmailStatus.handler
    events:
      - alb: 
        listenerArn: ${opt:albListener}
        priority: 10
        conditions:
          method: 
            - POST
          path: /email-status-listener
          header:
            name: authorization
            values:
              - ${opt:basicAuth}
    environment:
      MQ_DESTINATION: ${opt:MQ_DESTINATION}
      MQ_HOST: ${opt:MQ_HOST}
      MQ_PASSWORD: ${opt:MQ_PASSWORD}
      MQ_USERNAME: ${opt:MQ_USERNAME}
    vpc:
      securityGroupIds:
        - ${opt:securityGroup}
      subnetIds:
        "Fn::Split":
          - ","
          - ${opt:privateSubnets}
2

Hi nidersa,

The problem you are having here is related with the indentation in your serverless.yml file. With you current indent the serverless framework receives something like:

{
   "events": [
      {
         "alb": null,
         "listenerArn": "${opt:albListener}",
         "priority": 10,
         "conditions": {
            "method": [
               "POST"
            ],
            "path": "/email-status-listener",
            "header": {
               "name": "authorization",
               "values": [
                  "${opt:basicAuth}"
               ]
            }
         }
      }
   ]
}

Here you can see the value for alb event is null, so try to indent inner content 2 spaces to the right and you should be good to go.

  events:
      - alb:
          listenerArn: ${opt:albListener}
          priority: 10
          conditions:
            method:
              - POST
            path: /email-status-listener
            header:
              name: authorization
              values:
                - ${opt:basicAuth}

I hope it helps!!