Boilerplate Lambda Typescript

Overview

This is a boilerplate to help you initiate AWS Lambda project using Typescript, in this boilerplate there are terraform code to provision the stacks and the initial Typescript source code in the sources directory

Features

• Terraform code to provision the AWS Lambda project
• Typescript source code in the sources directory
• Automatically load AWS Secrets Manager (parameter store) as environment variables
• Automatically load DynamoDB (table name) as environment variables
• Automatically create models for DynamoDB tables with the ability to read, write, delete, and scan
• Decorator example to log the execution time of the method
• Datadog example integration to stream the metrics of statistic decorator to Datadog
• Lambda layer to store the dependencies of the project
• Lambda scheduler to schedule the function invocation

Project Structures

.
├── sources
│   ├── package-lock.json
│   ├── package.json
│   ├── src
│   │   ├── decorators
│   │   │   └── statistic.decorator.ts
│   │   ├── functions
│   │   │   ├── booking-create.function.ts
│   │   │   ├── booking-search.function.ts
│   │   │   └── flight-search.function.ts
│   │   ├── helpers
│   │   │   ├── chunk.helper.ts
│   │   │   └── parameter-store.helper.ts
│   │   ├── index.ts
│   │   ├── libraries
│   │   │   ├── datadog.library.ts
│   │   │   └── dynamodb.library.ts
│   │   └── models
│   │       ├── booking.model.ts
│   │       ├── flight.model.ts
│   │       ├── model.ts
│   │       └── transaction.model.ts
│   └── tsconfig.json
├── README.md
├── data.tf
├── main.tf
├── providers.tf
├── terraform.tfvars.example
└── variables.tf

While doing a terraform apply command, theese are the things that will be created:

• AWS Lambda Function, in the main.tf there's a logic on creating AWS Lambda function based on files with format *.function.ts under sources/src/functions directory, so the number of AWS Lambda function created is based on *.function.ts files
• AWS System Manager Parameter Store, in the main.tf there's a logic on creating AWS Parameter Store with prefix set on parameter_store_path under variables.tf based on:
  • parameter_store_list attributes under variables.tf file
  • dynamodb_table_list attributes under variables.tf file which will create a Parameter Store to store the table names of DynamoDB with format dynamodb-table-{table_name}
  • service_version attributes under variables.tf file which will create a Parameter Store to store the version of the service

Another context related to the Typescript source code:

• sources/src/helpers is the collection of functional helpers such as populateEnvironmentVariables() you can freely add another functional helpers under this directory
• sources/src/libraries is the collection of class helpers such as DatadogLibrary which contains all Datadog functionality such as publishMetrics and publishEvents, or another example DynamoDBLibrary which contains putItem and getItem
• sources/src/decorators is the collection of Typescript decorators, the initial example is @statistic decorator which have the functionality to log the execution duration for the method that uses the decorators, the example also include the additional process to stream the statistic metrics into Datadog
• sources/src/index.ts is a bootstraper file which contains default exports.handlers function, which is the default function that will be called by AWS Lambda Function, this file contains logic to create the sources/src/functions/*.function.ts instance and create object then call the handler method
• sources/src/models is the collection of Typescript models, the initial example is Booking which is the model for DynamoDB table booking which automatically created by terraform code

Requirements

Name	Version
terraform	~> 1.1.9
aws	~> 4.10.0

Providers

Name	Version
archive	2.2.0
aws	4.10.0
null	3.1.1

Modules

Name	Source	Version
dynamodb-table-name	git@github.com:traveloka/terraform-aws-resource-naming.git	v0.22.0
lambda-function-name	git@github.com:traveloka/terraform-aws-resource-naming.git	v0.22.0
lambda-layer-name	git@github.com:traveloka/terraform-aws-resource-naming.git	v0.22.0

Resources

Name	Type
aws_cloudwatch_event_rule.lambda-function-trigger-schedule	resource
aws_cloudwatch_event_target.lambda-function-trigger-schedule	resource
aws_cloudwatch_log_group.lambda-function-log-group	resource
aws_dynamodb_table.dynamodb-table	resource
aws_iam_role.lambda-function-role	resource
aws_iam_role_policy.function-policy	resource
aws_kms_alias.service-alias	resource
aws_kms_key.service-key	resource
aws_lambda_function.lambda-function	resource
aws_lambda_layer_version.lambda-layer	resource
aws_lambda_permission.lambda-function-trigger-schedule	resource
aws_ssm_parameter.ssm-parameter-custom	resource
aws_ssm_parameter.ssm-parameter-dynamodb-table	resource
aws_ssm_parameter.ssm-parameter-service-version	resource
null_resource.lambda-function-source-builder	resource
null_resource.lambda-layer-source-builder	resource
null_resource.typescript-source-model-builder	resource
archive_file.lambda-function-source	data source
archive_file.lambda-layer-source	data source
archive_file.typescript-source	data source
aws_caller_identity.current	data source
aws_iam_policy_document.function-policy	data source
aws_region.current	data source

Inputs

Name	Description	Type	Default	Required
default_tags	The default tags for the service	map(string)	{}	no
dynamodb_table_list	The list of dynamodb tables to be used for the service, e.g. [   {     "name": "booking",     "key": "id"   },   {     "name": "flight",     "key": "id"   },   {     "name": "transaction",     "key": "booking_id",     "range_key": "flight_id"   } ]	list(object({ name = string, key = string, range_key = optional(string), }))	[]	no
lambda_function_configuration	The custom configuration for the Lambda Function, e.g. {   "booking-create": {     "lambda_memory_size": 1024,     "lambda_timeout": 300   } }	map(object({ lambda_memory_size = optional(number), lambda_timeout = optional(number), schedule_expression = optional(string), }))	{}	no
parameter_store_list	The list of parameter store keys to be used for the service, e.g. [   "datadog-api-key",   "datadog-app-key",   "sentry-dsn",   "sentry-environment" ]	list(string)	[]	no
service_domain	The 1st level of logical grouping of the service, e.g. 'api', 'web', 'db', etc.	string	n/a	yes
service_environment	The 3rd level of logical grouping of the service, e.g. 'dev', 'test', 'prod', etc.	string	n/a	yes
service_name	The 2nd level of logical grouping of the service, e.g. 'my-api', 'my-web', 'my-db', etc.	string	n/a	yes
service_version	The version of the service	string	"v1.0.0"	no

Outputs

Name	Description
dynamodb-table-list	List of DynamoDB Tables created
kms-alias	KMS Alias created
kms-key	KMS Key created
lambda-function-list	List of Lambda Functions created
lambda-function-role	Lambda Function Role created
lambda-layer	Lambda Layer created
ssm-parameter-list	List of SSM Parameters created

How to Setup

To setup the example you can follow the following steps:

• Copy the terraform.tfvars.example file to terraform.tfvars
• Run terraform init
• Run terraform apply