Terraform AWS Lambda DynamoDB

Terraform module for AWS Lambda DynamoDB infrastructure

Table of Contents

• Features
• Usage
• Deployment
• Example

Features

Terraform module which deploys Lambda & DynamoDB to be used as building block.

Attention

Starting from version 1.4.0, this module targets Terraform 0.12+. If you are using Terraform <=v0.11 you must use up to version 1.3.0.

Lambda

This module is created with full customization by user.

• Can use either local filename path lambda_file_name or remote S3 bucket configuration.
• Supports Lambda Layers
• Supports VPC

Must use either the local filename or S3 option as they are mutually exclusive. Exports S3 bucket to allow usage by multiple Lambda's but given lambda_code_s3_bucket_use_existing=true it will use existing S3 bucket provided in lambda_code_s3_bucket_existing.

• This module by default, if created allows accompanying Lambda access to dynamodb:PutItem, dynamodb:DescribeTable, dynamodb:DeleteItem, dynamodb:GetItem, dynamodb:Scan, dynamodb:Query all DynamoDB tables.

DynamoDB

This module is optional. Lambda is created with R/W permission for DynamoDB to allow Lambda creation of tables or optionally to create them before-hand with this script.

• This module by default, if created allows accompanying Lambda access to dynamodb:PutItem, dynamodb:DescribeTable, dynamodb:DeleteItem, dynamodb:GetItem, dynamodb:Scan, dynamodb:Query all DynamoDB tables.

NOTE

The attributes and table properties are in separate lists due to current HCL language parser limitations. Will update to single cohesive object once situation improves.

Usage

module "lambda-dynamodb" {
  source  = "crisboarna/lambda-dynamodb/aws"
  version = "1.4.0"

  # insert the required variables here
}

Deployment

1. Run build process to generate Lambda ZIP file locally to match lambda_zip_path variable path
2. Provide all needed variables from variables.tf file or copy paste and change example below
3. Create/Select Terraform workspace before deployment
4. Run terraform plan -var-file="<.tfvars file> to check for any errors and see what will be built
5. Run terraform apply -var-file="<.tfvars file> to deploy infrastructure

Example Deployment Script

#!/usr/bin/env bash

if [[ ! -d .terraform ]]; then
  terraform init
fi
if ! terraform workspace list 2>&1 | grep -qi "$ENVIRONMENT"; then
  terraform workspace new "$ENVIRONMENT"
fi
terraform workspace select "$ENVIRONMENT"
terraform get
terraform plan -var-file=$1
terraform apply -var-file=$1

Example

module "lambda_dynamodb" {
  source  = "crisboarna/lambda-dynamodb"
  version = "v1.4.0"

  #Global
  region = "eu-west-1"
  project = "Awesome Project"
   
  #Lambda
  lambda_function_name = "Awesome Endpoint"
  lambda_description = "Awesome HTTP Endpoint Lambda"
  lambda_runtime = "nodejs8.10"
  lambda_handler = "dist/bin/lambda.handler"
  lambda_timeout = 30
  lambda_code_s3_bucket = "awesome-project-bucket"
  lambda_code_s3_key = "awesome-project.zip"
  lambda_code_s3_storage_class = "ONEZONE_IA"
  lambda_code_s3_bucket_visibility = "private"
  lambda_zip_path = "../../awesome-project.zip"
  lambda_memory_size = 256
  lambda_vpc_security_group_ids = [aws_security_group.vpc_security_group.id]
  lambda_vpc_subnet_ids = [aws_subnet.vpc_subnet_a.id]
  lambda_layers = [data.aws_lambda_layer_version.layer.arn]

  #DynamoDB
  dynamodb_table_properties = [
    { 
      name = "Awesome Project Table 1"
    },
    {
      name = "Awesome Project Table 2",
      read_capacity = 2,
      write_capacity = 3,
      hash_key = "KEY"
      range_key = ""
      stream_enabled = "true"
      stream_view_type = "NEW_IMAGE"
    }
  ]
  
  dynamodb_table_attributes = [[
    {
      name = "KEY"
      type = "S"
    }],[
    {
      name = "PRIMARY_KEY"
      type = "N"
    }, {
      name = "SECONDARY_KEY"
      type = "S"
    }
   ]]
   
   dynamodb_table_secondary_index = [[
    {
      name               = "GameTitleIndex"
      hash_key           = "GameTitle"
      range_key          = "TopScore"
      write_capacity     = 10
      read_capacity      = 10
      projection_type    = "INCLUDE"
      non_key_attributes = ["UserId"]
    }
   ]]
   
   dynamodb_policy_action_list = ["dynamodb:PutItem", "dynamodb:DescribeTable", "dynamodb:DeleteItem", "dynamodb:GetItem", "dynamodb:Scan", "dynamodb:Query"]
   dynamodb_table_ttl = [[
      {
        attribute_name = "ttl"
        enabled = true
      }
   ]]
       
  #Tags
  tags = {
    project = "Awesome Project"
    managedby = "Terraform"
  }
  
  #Lambda Environment variables
  environment_variables = {
    NODE_ENV = "production"
  }
}