Serverless backend with ALB

serverless framework with a load balancer (with vpc/subnet configuration) connected to a lambda in aws.

• creates a LoadBalancer, HTTP Listener and Lambda
• links the Listener and Lambda
• stores the LoadBalancerDNSName (url) in ParameterStore

Install Requirements

npm install serverless -g
npm install

Modify Config

Modify the file /config/serverless.config.yml

• VPC / Subnet configuration for load balancer
• Scheme for load balancer

    VPC_ID: 'vpc-xxxxxxxxx'
    SUBNET_ID_A: "subnet-xxxxxxxxx"
    SUBNET_ID_B: "subnet-xxxxxxxxx"
    SUBNET_ID_C: "subnet-xxxxxxxxx"
    SCHEME: "internet-facing" or "internal" # load balancer scheme - 

Deploy solution

sls deploy

Result:

1. Execute info to get load balancer url

sls info -v

you should get the full output containing the load balancer url.

Stack Outputs
LoadBalancerDNSName: serverless-load-balancer-258977035.eu-central-1.elb.amazonaws.com
HandlerLambdaFunctionQualifiedArn: arn:aws:lambda:eu-central-1:368555349508:function:serverless-load-balancer-dev-handler:1
ServerlessDeploymentBucketName: serverless-load-balancer-serverlessdeploymentbuck-16pgpyls1225e

2. Paste the LoadBalancerDNSName Value into your browser or execute postman to set a GET statement against the URL.

Expected Response:

    Successfully executed lambda call via loadbalancer