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
when to use load balancer instead of api gateway ?
- https://serverless-training.com/articles/save-money-by-replacing-api-gateway-with-application-load-balancer/
- https://serverless-training.com/articles/api-gateway-vs-application-load-balancer-technical-details/
npm install serverless -g
npm install
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 -
sls deploy
- 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
- Paste the LoadBalancerDNSName Value into your browser or execute postman to set a GET statement against the URL.
Successfully executed lambda call via loadbalancer
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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
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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.