Attempt to create a route on an ALB to be redirected to a Lambda WIP

aws-alb-lambda-terraform.tf

# local vars
locals {
  name     = "hello"
  env      = "dev"
  lb_name  = join("-", list("TF", local.env, local.name))
  zip_path = "${local.name}.zip"
  tags     = {
    env = local.env
  }
}

# data sources
data "aws_vpc" "default" {
  tags {
    env = local.env
  }
}

data "aws_subnet_ids" "default" {
  vpc_id = "${data.aws_vpc.default.id}"

  tags {
    env = local.env
  }
}

data "aws_security_groups" "default" {
  tags {
    env = local.env
  }
}

data "aws_iam_role" "base" {
  name = "lambda-base-role"
}

# alb and lambda resources
resource "aws_lambda_function" "lambda" {
  # Lambda zip File config
  filename         = local.zip_path
  source_code_hash = base64sha256(file(local.zip_path))

  # Function definition
  function_name = local.name
  role          = data.aws_iam_role.base.arn
  handler       = "main.handle"
  runtime       = "python3.7"
  memory_size   = "128"
  timeout       = "30"
  publish       = false

  # Network config
  vpc_config {
    subnet_ids         = [data.aws_subnet_ids.default.ids]
    security_group_ids = [data.aws_security_groups.default.ids]
  }

  tags = local.tags
}

resource "aws_lb" "default" {
  name               = local.lb_name
  internal           = false
  load_balancer_type = "application"
  security_groups    = [data.aws_security_groups.default.ids]
  subnets            = [data.aws_subnet_ids.default.ids]

  enable_deletion_protection = true
}

resource "aws_lb_target_group" "default" {
  name        = "${local.lb_name}-TG"
  target_type = "lambda"
}

resource "aws_lb_listener" "default" {
  load_balancer_arn = aws_lb.default.arn
  port              = "80"
  protocol          = "HTTP"

  default_action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.default.arn
  }
}

resource "aws_lb_listener_rule" "lambda" {
  listener_arn = aws_lb_listener.default.arn
  priority     = 100

  action {
    type             = "forward"
    target_group_arn = aws_lb_target_group.default.arn
  }

  condition {
    path_pattern {
      values = ["/lambda/${local.name}"]
    }
  }
}

resource "aws_lambda_permission" "with_lb" {
  statement_id  = "AllowExecutionFromLB"
  action        = "lambda:InvokeFunction"
  function_name = local.name
  principal     = "elasticloadbalancing.amazonaws.com"
  source_arn    = aws_lb_target_group.default.arn
}

resource "aws_lb_target_group_attachment" "default" {
  target_group_arn = aws_lb_target_group.default.arn
  target_id        = aws_lambda_function.lambda.arn
}

# return base url
output "base_url" {
  value = aws_lb.default.public_dns
}

has this worked for you?

@gitgoose yes!

How did you figure it out eventually?