Terraform AWS Lambda Function

This is an opinionated setup that uses Terraform to manage an AWS Lambda function.

What will this setup do?

This is a Terraform configuration that manages the an AWS EKS stack. It will create the following resources:

• AWS Lambda Function: Lambda function using a Docker image to run code
• AWS S3 Bucket: Used to store the attachments for the Lambda Function
• AWS Policy: Allows the Lambda Function to access the S3 Bucket
• AWS ECR Repository: Used to store the Docker image for the Lambda Function
• Docker Image Build and Push to AWS ECR repository

This setup the Terraform CLI to manage the IllumiDesk stack using Terraform Workspaces.

Requirements

Ensure you have the following installed on your local machine:

• aws cli
• docker.
• sam cli.
• terraform

You must have an AWS account and provide your AWS Access Key ID and AWS Secret Access Key.

The values for AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY should be saved as environment variables on your workspace or they can be provided as variables in the *.tfvars file.

Quick Start

Copy the example.tfvars file to <environment>.tfvars and update the values with your AWS credentials.

cp example.tfvars dev.tfvars

Create and/or select a Terraform workspace.

terraform workspace new dev

Initialize the Terraform configuration.

terraform init

Plan the Terraform configuration (replace <environment> with the name of your environment):

terraform plan -var-file=<environment>.tfvars

For the development environment:

terraform plan -var-file=dev.tfvars

For the production environment:

terraform plan -var-file=prod.tfvars

Apply the Terraform configuration.

terraform apply -var-file=dev.tfvars

Assert the Lambda Function with Boto3

From the tests/lambda_function directory, run the following command to test the Lambda function with Boto3. Ensure that the ARN value is exported with the LAMBDA_FUNCTION_ARN environment variable before executing the test:

# example for development environment lambda function
export LAMBDA_FUNCTION_ARN=arn:aws:lambda:us-east-1:860100747351:function:app-dev-docker-lambda_handler
python test_lambda_with_arn.py

This should output a result similar to the following:

{'statusCode': 200, 'body': '{"result": {"a": 5, "b": 20}}'}

Terraform Reference

Requirements

Name	Version
terraform	>= 0.13.1
aws	>= 3.19
docker	>= 2.12
random	>= 2.0

Providers

Name	Version
aws	>= 3.19
random	>= 2.0

Modules

Name	Source	Version
docker_image	./docker-build	n/a
lambda_function_from_container_image	terraform-aws-modules/lambda/aws	~> 4.13

Resources

Name	Type
random_pet.this	resource
aws_caller_identity.this	data source
aws_ecr_authorization_token.token	data source
aws_region.current	data source

Inputs

No inputs.

Outputs

Name	Description
docker_image_uri	The ECR Docker image URI used to deploy Lambda Function
lambda_cloudwatch_log_group_arn	The ARN of the Cloudwatch Log Group
lambda_function_arn	The ARN of the Lambda Function
lambda_function_arn_static	The static ARN of the Lambda Function. Use this to avoid cycle errors between resources (e.g., Step Functions)
lambda_function_invoke_arn	The Invoke ARN of the Lambda Function
lambda_function_kms_key_arn	The ARN for the KMS encryption key of Lambda Function
lambda_function_last_modified	The date Lambda Function resource was last modified
lambda_function_name	The name of the Lambda Function
lambda_function_qualified_arn	The ARN identifying your Lambda Function Version
lambda_function_region	The region of the Lambda Function
lambda_function_source_code_hash	Base64-encoded representation of raw SHA-256 sum of the zip file
lambda_function_source_code_size	The size in bytes of the function .zip file
lambda_function_version	Latest published version of Lambda Function
lambda_layer_arn	The ARN of the Lambda Layer with version
lambda_layer_created_date	The date Lambda Layer resource was created
lambda_layer_layer_arn	The ARN of the Lambda Layer without version
lambda_layer_source_code_size	The size in bytes of the Lambda Layer .zip file
lambda_layer_version	The Lambda Layer version
lambda_role_arn	The ARN of the IAM role created for the Lambda Function
lambda_role_name	The name of the IAM role created for the Lambda Function