main.tf

### LAMBDA

module "lambda_function" {
  source = "terraform-aws-modules/lambda/aws"

  function_name = "outdoor-activities-generator"
  description   = "Generates a map containing your outdoor activities"
  handler       = "main.lambda_handler"
  runtime       = "python3.11"
  timeout       = 60

  source_path = "../src/lambda"

  environment_variables = {
    START_LATITUDE             = var.start_latitude
    START_LONGITUDE            = var.start_longitude
    ZOOM_START                 = var.zoom_start
    INPUT_BUCKET               = module.input_bucket.s3_bucket_id
    OUTPUT_BUCKET              = module.output_bucket.s3_bucket_id
    S3_OBJECT_NAME             = "map.html"
    CLOUDFRONT_DISTRIBUTION_ID = module.cloudfront.cloudfront_distribution_id
  }

  layers = [
    module.lambda_layer.lambda_layer_arn,
  ]

  attach_policy = true
  policy        = aws_iam_policy.lambda_policy.arn
}

module "lambda_layer" {
  source = "terraform-aws-modules/lambda/aws"

  create_function = false
  create_layer    = true

  layer_name          = "outdoor-activities-layer"
  description         = "Lambda layer containing everything for Outdoor Activities"
  compatible_runtimes = ["python3.11"]
  runtime             = "python3.11" 
   
  source_path = [
    {
      path             = "../src/lambda-layer"
      pip_requirements = true
      prefix_in_zip    = "python" # required to get the path correct
    }
  ]
}

resource "aws_iam_policy" "lambda_policy" {
  name = "outdoor-activities-generator-policy"

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action   = "s3:GetObject"
        Effect   = "Allow"
        Resource = "${module.input_bucket.s3_bucket_arn}/*"
      },
      {
        Action   = "s3:ListBucket"
        Effect   = "Allow"
        Resource = module.input_bucket.s3_bucket_arn
      },
      {
        Action   = "s3:PutObject"
        Effect   = "Allow"
        Resource = "${module.output_bucket.s3_bucket_arn}/*"
      },
      {
        Action   = "cloudfront:GetDistribution"
        Effect   = "Allow"
        Resource = module.cloudfront.cloudfront_distribution_arn
      },
      {
        Action   = "cloudfront:CreateInvalidation"
        Effect   = "Allow"
        Resource = module.cloudfront.cloudfront_distribution_arn
      }
    ]
  })
}

resource "aws_lambda_permission" "allow_bucket" {
  statement_id  = "AllowExecutionFromS3Bucket"
  action        = "lambda:InvokeFunction"
  function_name = module.lambda_function.lambda_function_arn
  principal     = "s3.amazonaws.com"
  source_arn    = module.input_bucket.s3_bucket_arn
}

resource "aws_s3_bucket_notification" "bucket_notification" {
  bucket = module.input_bucket.s3_bucket_id

  lambda_function {
    lambda_function_arn = module.lambda_function.lambda_function_arn
    events              = ["s3:ObjectCreated:*"]
  }

  depends_on = [aws_lambda_permission.allow_bucket]
}