This is an exercise in creating an serverless api using aws api gw, lambda and dynamodb. It uses multiple lambda functions on purpose ...

This api will have a list of artists and songs

• api gw with 3 methods:
  • get: lists all songs in the catalog
  • put: adds an artist and song to the catalog
  • delete: adds an artist and song to the catalog

This code will create a dynamodb table with pre populated songs by prince

There are 3 internal lambdas, one per each method detailed above, these run in a vpc with no internet access, and have an IAM role that allows access to the dynamodb table above, the vpc hosting these lambdas also has a dynamodb endpoint

There are 3 external lambdas, one per each method detailed above, these run in a vpc with internet access ( 1 igw and a nat gw per AZ), and have an IAM role that allows invocation of the internal lambdas. egrees/ingress access of the lambdas is controled by NACLS

The api GW root has 3 methods, each mapped to a lambda function above, the Api gw url is included in the Terraform outputs

Internal vpc: will have 2 private subnets, one per each AZ provided in azs variable External vpc: will have 2 private and 2 public subnets, one per AZ provided in azs variable The code will use:

• 2 x /28 subnets for private subnets
• 2 x /30 subnets for private subnets

For this exercise most of the values are hardcoded, simply create a terraform.tfvars with owner=somename and execute:

1. terraform init
2. terraform apply

execute:

1. terraform destroy

you may change the following inputs:

owner         = "moti"
internal_cidr = "192.168.0.0/24"
external_cidr = "192.168.1.0/24"
region = "us-west-2"
azs    = ["a", "b"]

Once terraform is done you can use the following curls to the api:

curl -X POST --header "Content-Type: application/json" --data '{}' https://url.of.api/get

curl -X POST --header "Content-Type: application/json" --data '{ "artist":"prince"}' https://url.of.api/get

curl -X POST --header "Content-Type: application/json" --data '{ "artist":"prince","song":"Nothing Compares 2 U"}' https://url.of.api/put

curl -X POST --header "Content-Type: application/json" --data '{ "artist":"prince","song":"Nothing Compares 2 U"}' https://url.of.api/delete

You can also test the api using ./bin/test.sh api url

This code is the bare minimum to achieve this goal and is not meant to be used for real life application, here are some of the main reasons:

1. lambdas code does not do any data validation/sanitation
2. lambdas are caped at 1rps and do not have autoscaling
3. dynamodb does not have point in time snapshots
4. terraform state file is saved localy and not to a remove backend