Awesome

serverless-load-balancer

serverless framework sample that shows how to deploy 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

This feature has been introduced in v 1.45 and extended in 1.46 serverless framework

see changelog

when to use load balancer instead of api gateway ?

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 (see aws documentation)

    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:

Execute info to get load balancer url

sls info -v

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

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

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

Additional things to know

This sample does not care if the lambda and the load balancer are both in a vpc. It could be mixed in anyway dependent of the use case
The load balancer url will be stored as Parameter in Parameter store. This helps to reference the loadbalancer url easily tool-independent in other stacks.