New serverless pattern - alb-lambda-terraform

alb-lambda-terraform/.gitignore

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+*.js
+!jest.config.js
+*.d.ts
+node_modules
+!/lib

alb-lambda-terraform/.npmignore

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+*.ts
+!*.d.ts
+

alb-lambda-terraform/README.md

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+# Application Load balancer with AWS Lambda as target with Terraform
+
+This pattern demonstrates how to create an Application Load Balancer with AWS Lambda as target. Implemented in Terraform.
+
+Learn more about this pattern at Serverless Land Patterns: https://serverlessland.com/patterns/alb-lambda-terraform
+
+Important: this application uses various AWS services and there are costs associated with these services after the Free Tier usage - please see the [AWS Pricing page](https://aws.amazon.com/pricing/) for details. You are responsible for any AWS costs incurred. No warranty is implied in this example.
+
+## Requirements
+
+* [Create an AWS account](https://portal.aws.amazon.com/gp/aws/developer/registration/index.html) if you do not already have one and log in. The IAM user that you use must have sufficient permissions to make necessary AWS service calls and manage AWS resources.
+* [AWS CLI](https://docs.aws.amazon.com/cli/latest/userguide/install-cliv2.html) installed and configured
+* [Git Installed](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git)
+* [Terraform Installed](https://developer.hashicorp.com/terraform/downloads)
+
+## Deployment Instructions
+
+1. Create a new directory, navigate to that directory in a terminal and clone the GitHub repository:
+    ``` 
+    git clone https://github.com/aws-samples/serverless-patterns
+    ```
+2. Change directory to the pattern directory:
+    ```
+    cd alb-lambda-terraform
+    ```
+3. From the command line, run:
+    ```
+    terraform init
+    ```
+4. From the command line, run:
+    ```
+    terraform plan
+    ```
+5. From the command line, run:
+    ```
+    terraform apply --auto-approve
+    ```
+
+## Testing
+
+1. In the stack output, you can see `alb_url`. When you access the url, you should see the response "Hello World" from Lambda.
+
+** Please note: Application Load Balancer's default settings for health check are 5 consecutive health check successes with 35 seconds interval. So, it will take couple of minutes for the target to be healthy.
+
+## Cleanup
+
+1. To delete the stack, run:
+    ```bash
+    terraform destroy --auto-approve
+    ```
+----
+Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+
+SPDX-License-Identifier: MIT-0

alb-lambda-terraform/example-pattern.json

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+{
+    "title": "Application Load Balancer with Lambda as target",
+    "description": "Create an Application Load Balancer with Lambda as target using Terraform",
+    "language": "TypeScript",
+    "level": "200",
+    "framework": "Terraform",
+    "introBox": {
+        "headline": "How it works",
+        "text": [
+            "This sample project demonstrates how to create an Application Load Balancer with AWS Lambda as target.",
+            "Implemented in Terraform."
+        ]
+    },
+    "gitHub": {
+        "template": {
+            "repoURL": "https://github.com/aws-samples/serverless-patterns/tree/main/alb-lambda-terraform",
+            "templateURL": "serverless-patterns/alb-lambda-terraform",
+            "projectFolder": "alb-lambda-terraform",
+            "templateFile": "alb-lambda-terraform/main.tf"
+        }
+    },
+    "resources": {
+        "bullets": [
+            {
+                "text": "Application Load Balancer",
+                "link": "https://docs.aws.amazon.com/elasticloadbalancing/latest/application/introduction.html"
+            },
+            {
+                "text": "ALB - Lambda target",
+                "link": "https://docs.aws.amazon.com/elasticloadbalancing/latest/application/lambda-functions.html"
+            }
+        ]
+    },
+    "deploy": {
+        "text": [
+            "terraform init",
+            "terraform apply"
+        ]
+    },
+    "testing": {
+        "text": [
+            "See the Github repo for detailed testing instructions."
+        ]
+    },
+    "cleanup": {
+        "text": [
+            "terraform destroy",
+			"terraform show"
+        ]
+    },
+    "authors": [
+        {
+            "name": "Sumit Bhati",
+            "image": "https://avatars.githubusercontent.com/u/139027745",
+            "bio": "I am a Customer Solutions Manager at AWS"
+        }
+    ]
+}

alb-lambda-terraform/main.tf

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+# Required providers configuration
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~>4.52.0"
+    }
+  }
+
+  required_version = "~> 1.0"
+}
+
+# AWS provider configuration
+provider "aws" {
+  profile = "default"
+  region = "us-east-1"
+}
+
+# Create AWS VPC 
+resource "aws_vpc" "vpc" {
+  cidr_block = var.vpc_cidr
+
+}
+
+# Create public subnet 1
+resource "aws_subnet" "public_subnet1" {
+  cidr_block = "10.0.1.0/24"
+  vpc_id = aws_vpc.vpc.id
+  availability_zone = "${var.region}a"
+  tags = {
+    Name = "Subnet for ${var.region}a"
+  }
+}
+
+# Create public subnet 2
+resource "aws_subnet" "public_subnet2" {
+  cidr_block = "10.0.2.0/24"
+  vpc_id = aws_vpc.vpc.id
+  availability_zone = "${var.region}b"
+  tags = {
+    Name = "Subnet for ${var.region}b"
+  }
+}
+
+# Create a route table 
+resource "aws_route_table" "public_rt" {
+  vpc_id = aws_vpc.vpc.id
+
+  route {
+    cidr_block = "0.0.0.0/0"
+    gateway_id = aws_internet_gateway.gw.id
+  }
+
+  tags = {
+    Name = "public_rt"
+  }
+}
+
+# Associate the route table with public subnet 1
+resource "aws_route_table_association" "public_rt_table_a" {
+  subnet_id      = aws_subnet.public_subnet1.id
+  route_table_id = aws_route_table.public_rt.id
+}
+
+# Associate the route table with public subnet 2
+resource "aws_route_table_association" "public_rt_table_b" {
+  subnet_id      = aws_subnet.public_subnet2.id
+  route_table_id = aws_route_table.public_rt.id
+}
+
+# Create an Internet Gateway
+resource "aws_internet_gateway" "gw" {
+  vpc_id = aws_vpc.vpc.id
+}
+
+# Create IAM Role for Lambda Function
+resource "aws_iam_role" "lambda_role" {
+name   = "Lambda_Function_Role"
+assume_role_policy = <<EOF
+{
+ "Version": "2012-10-17",
+ "Statement": [
+   {
+     "Action": "sts:AssumeRole",
+     "Principal": {
+       "Service": "lambda.amazonaws.com"
+     },
+     "Effect": "Allow",
+     "Sid": ""
+   }
+ ]
+}
+EOF
+}
+
+# Create IAM policy for Lambda to write logs
+resource "aws_iam_policy" "iam_policy_for_lambda" {
+
+ name         = "aws_iam_policy_for_terraform_aws_lambda_role"
+ path         = "/"
+ description  = "AWS IAM Policy for managing aws lambda role"
+ policy = <<EOF
+{
+ "Version": "2012-10-17",
+ "Statement": [
+   {
+     "Action": [
+       "logs:CreateLogGroup",
+       "logs:CreateLogStream",
+       "logs:PutLogEvents"
+     ],
+     "Resource": "arn:aws:logs:*:*:*",
+     "Effect": "Allow"
+   }
+ ]
+}
+EOF
+}
+
+# Attach the IAM policy for writing logs to the Lambda Role
+resource "aws_iam_role_policy_attachment" "attach_iam_policy_to_iam_role" {
+ role        = aws_iam_role.lambda_role.name
+ policy_arn  = aws_iam_policy.iam_policy_for_lambda.arn
+}
+
+# Create a security group for application load balancer
+resource "aws_security_group" "load_balancer_sg" {
+  name        = "myLoadBalancerSG"
+  vpc_id      = aws_vpc.vpc.id
+  ingress {
+    from_port   = 80
+    to_port     = 80
+    protocol    = "tcp"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+  tags = {
+    Name = "myLoadBalancerSG"
+  }
+}
+
+# Create the application load balancer
+resource "aws_lb" "load_balancer" {
+  name               = "myLoadBalancer"
+  internal           = false
+  load_balancer_type = "application"
+  security_groups    = [aws_security_group.load_balancer_sg.id]
+  subnets            = [aws_subnet.public_subnet1.id,aws_subnet.public_subnet2.id]
+  tags = {
+    Name = "myLoadBalancer"
+  }
+}
+
+# Create the ALB listener with the target group.
+resource "aws_lb_listener" "listener" {
+  load_balancer_arn = aws_lb.load_balancer.arn
+  port              = 80
+  protocol          = "HTTP"
+  default_action {
+    type             = "forward"
+    target_group_arn = "${aws_lb_target_group.target_group.arn}"
+  }
+}
+
+# Create the ALB target group for Lambda
+resource "aws_lb_target_group" "target_group" {
+  name     = "myLoadBalancerTargets"
+  target_type = "lambda"
+  vpc_id   = aws_vpc.vpc.id
+}
+
+# Attach the ALB target group to the Lambda Function
+resource "aws_lb_target_group_attachment" "target_group_attachment" {
+  target_group_arn = aws_lb_target_group.target_group.arn
+  target_id        = aws_lambda_function.lambda_function.arn
+}
+
+# Create the Lambda Function
+resource "aws_lambda_function" "lambda_function" {
+  function_name = "lambdaFunction"
+  runtime       = "nodejs14.x"
+  handler       = "index.handler"
+  filename      = "lambda.zip"
+  role          = aws_iam_role.lambda_role.arn
+  depends_on    = [aws_iam_role_policy_attachment.attach_iam_policy_to_iam_role]
+  tags = {
+    Name = "lambdaFunction"
+  }
+}
+
+# Allow the application load balancer to access Lambda Function
+resource "aws_lambda_permission" "with_lb" {
+  statement_id  = "AllowExecutionFromlb"
+  action        = "lambda:InvokeFunction"
+  function_name = aws_lambda_function.lambda_function.arn
+  principal     = "elasticloadbalancing.amazonaws.com"
+  source_arn    = aws_lb_target_group.target_group.arn
+}

alb-lambda-terraform/outputs.tf

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+# Output value definitions
+
+output "alb_url" {
+  value = "http://${aws_lb.load_balancer.dns_name}"
+}
+

alb-lambda-terraform/variables.tf

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+variable "region" {
+    type=string
+    description = "AWS Region where deploying resources"
+    default = "us-east-1"
+}
+
+variable "vpc_cidr" {
+    type=string
+    description = "CIDR block for Batch VPC"
+    default = "10.0.0.0/16"
+}