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fix subnet variable assignments to VPC module and other terraform deprecations
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README.md

Hero

Repository containing various Terraform code

Lots of Terraform recipes for doing things, aimed for copy and pasting into projects.

Knowledge-as-code

Terraform is an ideal knowledge transfer tool that can communicate the minutea of using certain technology combinations. We use this at Futurice to disseminate hard won learnings across projects and industries, increasing the development velocity for all of our clients.

Read more about specific projects

A few of the recipes have associated blog posts.

Contribution

External contributions welcome! All that we ask is that the recipe is interesting, and that it worked at some point. There is no expectation of maintenance (maintained projects should probably have their own repository). No two projects are alike, and so, we expect most uses of this repository to require customization.

To regenerate the readme, run npm run readme

Directory layout

  • aws
    • aws/aws_domain_redirect
    • aws/aws_ec2_ebs_docker_host
      • resource aws_instance
      • resource aws_key_pair
      • resource aws_security_group
      • resource aws_security_group_rule
      • resource aws_volume_attachment
      • resource null_resource
    • aws/aws_lambda_api
      • resource aws_acm_certificate
      • resource aws_acm_certificate_validation
      • resource aws_api_gateway_base_path_mapping
      • resource aws_api_gateway_deployment
      • resource aws_api_gateway_domain_name
      • resource aws_api_gateway_integration
      • resource aws_api_gateway_integration_response
      • resource aws_api_gateway_method
      • resource aws_api_gateway_method_response
      • resource aws_api_gateway_method_settings
      • resource aws_api_gateway_resource
      • resource aws_api_gateway_rest_api
      • resource aws_api_gateway_stage
      • resource aws_iam_policy
      • resource aws_iam_role
      • resource aws_iam_role_policy_attachment
      • resource aws_lambda_function
      • resource aws_lambda_permission
      • resource aws_route53_record
    • aws/aws_lambda_cronjob
      • resource aws_cloudwatch_event_rule
      • resource aws_cloudwatch_event_target
      • resource aws_iam_policy
      • resource aws_iam_role
      • resource aws_iam_role_policy_attachment
      • resource aws_lambda_function
      • resource aws_lambda_permission
    • aws/aws_mailgun_domain
      • resource aws_route53_record
      • resource mailgun_domain
    • aws/aws_reverse_proxy
      • resource aws_acm_certificate
      • resource aws_acm_certificate_validation
      • resource aws_cloudfront_distribution
      • resource aws_iam_policy
      • resource aws_iam_role
      • resource aws_iam_role_policy_attachment
      • resource aws_lambda_function
      • resource aws_route53_record
    • aws/aws_static_site
      • resource aws_s3_bucket
      • resource aws_s3_bucket_policy
      • resource random_string
    • aws/aws_vpc_msk
      • resource aws_acmpca_certificate_authority
      • resource aws_cloudwatch_log_group
      • resource aws_eip
      • resource aws_iam_instance_profile
      • resource aws_iam_role
      • resource aws_iam_role_policy_attachment
      • resource aws_instance
      • resource aws_internet_gateway
      • resource aws_key_pair
      • resource aws_kms_alias
      • resource aws_kms_key
      • resource aws_msk_cluster
      • resource aws_msk_configuration
      • resource aws_nat_gateway
      • resource aws_route_table
      • resource aws_route_table_association
      • resource aws_security_group
      • resource aws_subnet
      • resource aws_vpc
      • resource random_id
      • resource random_uuid
    • aws/static_website_ssl_cloudfront_private_s3
      • resource aws_cloudfront_distribution
      • resource aws_cloudfront_origin_access_identity
      • resource aws_route53_record
      • resource aws_s3_bucket
      • resource aws_s3_bucket_policy
      • resource aws_s3_bucket_public_access_block
    • aws/wordpress_fargate
      • resource aws_appautoscaling_policy
      • resource aws_appautoscaling_target
      • resource aws_cloudfront_distribution
      • resource aws_cloudwatch_log_group
      • resource aws_cloudwatch_metric_alarm
      • resource aws_db_subnet_group
      • resource aws_ecs_cluster
      • resource aws_ecs_service
      • resource aws_ecs_task_definition
      • resource aws_efs_file_system
      • resource aws_efs_mount_target
      • resource aws_iam_policy
      • resource aws_iam_role
      • resource aws_iam_role_policy_attachment
      • resource aws_lb_listener_rule
      • resource aws_lb_target_group
      • resource aws_rds_cluster
      • resource aws_route53_record
      • resource aws_security_group
      • resource aws_ssm_parameter
      • resource random_string
  • azure
    • azure/azure_linux_docker_app_service
      • resource azurerm_app_service
      • resource azurerm_app_service_plan
      • resource azurerm_app_service_slot
      • resource azurerm_application_insights
      • resource azurerm_application_insights_web_test
      • resource azurerm_container_registry
      • resource azurerm_key_vault
      • resource azurerm_key_vault_access_policy
      • resource azurerm_key_vault_secret
      • resource azurerm_monitor_action_group
      • resource azurerm_monitor_metric_alert
      • resource azurerm_monitor_scheduled_query_rules_alert
      • resource azurerm_role_assignment
      • resource random_string
    • azure/layers
      • resource azurerm_resource_group
      • resource azurerm_storage_account
      • resource azurerm_storage_blob
      • resource azurerm_storage_container
      • resource azurerm_subnet
      • resource azurerm_virtual_network
      • resource null_resource
  • generic
  • google_cloud
    • google_cloud/camunda-secure
      • resource google_cloud_run_service
      • resource google_project_iam_member
      • resource google_service_account
      • resource google_sql_database
      • resource google_sql_database_instance
      • resource google_sql_user
      • resource local_file
      • resource null_resource
    • google_cloud/camunda
      • resource google_cloud_run_service
      • resource google_cloud_run_service_iam_policy
      • resource google_project_iam_member
      • resource google_service_account
      • resource google_sql_database
      • resource google_sql_database_instance
      • resource google_sql_user
      • resource local_file
      • resource null_resource
    • google_cloud/CQRS_bigquery_memorystore
      • resource google_storage_bucket
      • resource google_storage_bucket_object
    • google_cloud/minecraft
      • resource google_compute_address
      • resource google_compute_disk
      • resource google_compute_firewall
      • resource google_compute_instance
      • resource google_compute_instance_iam_member
      • resource google_compute_network
      • resource google_project_iam_custom_role
      • resource google_project_iam_member
      • resource google_service_account
    • google_cloud/oathkeeper
      • resource google_cloud_run_service
      • resource google_cloud_run_service_iam_policy
      • resource google_service_account
      • resource google_storage_bucket
      • resource google_storage_bucket_iam_member
      • resource google_storage_bucket_object
      • resource local_file
      • resource null_resource
    • google_cloud/openresty-beyondcorp
      • resource google_cloud_run_service
      • resource google_cloud_run_service_iam_policy
      • resource google_project_iam_member
      • resource google_pubsub_subscription
      • resource google_pubsub_topic
      • resource google_service_account
      • resource local_file
      • resource null_resource
      • resource template_dir

aws

AWS Examples

aws/aws_domain_redirect

aws_domain_redirect

This module implements a domain that redirects clients to another URL. Useful for creating human-friendly shortcuts for deeper links into a site, or for dynamic links (e.g. download.example.com always pointing to your latest release).

Main features:

  • DNS entries are created automatically
  • HTTPS enabled by default
  • HTTP Strict Transport Security supported

Optional features:

  • Plain HTTP instead of HTTPS
  • Sending a permanent redirect (301 Moved Permanently) instead of default (302 Found)

Resources used:

  • Route53 for DNS entries
  • ACM for SSL certificates
  • CloudFront for proxying requests
  • Lambda@Edge for transforming requests
  • IAM for permissions

About CloudFront operations

This module manages CloudFront distributions, and these operations are generally very slow. Your terraform apply may take anywhere from 10 minutes up to 45 minutes to complete. Be patient: if they start successfully, they almost always finish successfully, it just takes a while.

Additionally, this module uses Lambda@Edge functions with CloudFront. Because Lambda@Edge functions are replicated, they can't be deleted immediately. This means a terraform destroy won't successfully remove all resources on its first run. It should complete successfully when running it again after a few hours, however.

Example

Assuming you have the AWS provider set up, and a DNS zone for example.com configured on Route 53:

# Lambda@Edge and ACM, when used with CloudFront, need to be used in the US East region.
# Thus, we need a separate AWS provider for that region, which can be used with an alias.
# Make sure you customize this block to match your regular AWS provider configuration.
# https://www.terraform.io/docs/configuration/providers.html#multiple-provider-instances
provider "aws" {
  alias  = "us_east_1"
  region = "us-east-1"
}

module "my_redirect" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_domain_redirect#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_domain_redirect?ref=v11.0"

  redirect_domain = "go.example.com"
  redirect_url    = "https://www.futurice.com/careers/"
}

Applying this will take a very long time, because both ACM and especially CloudFront are quite slow to update. After that, both http://go.example.com and https://go.example.com should redirect clients to https://www.futurice.com/careers/.

Inputs

Name Description Type Default Required
cloudfront_price_class Price class to use (100, 200 or "All", see https://aws.amazon.com/cloudfront/pricing/) string "100" no
comment_prefix This will be included in comments for resources that are created string "Domain redirect: " no
lambda_logging_enabled When true, writes information about incoming requests to the Lambda function's CloudWatch group string "false" no
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed, for S3 bucket name compatibility) string "aws-domain-redirect---" no
redirect_domain Domain which will redirect to the given redirect_url; e.g. "docs.example.com" string n/a yes
redirect_permanently Which HTTP status code to use for the redirect; if true, uses 301 Moved Permanently, instead of 302 Found string "false" no
redirect_url The URL this domain redirect should send clients to; e.g. "https://readthedocs.org/projects/example" string n/a yes
redirect_with_hsts Whether to send the Strict-Transport-Security header with the redirect (recommended for security) string "true" no
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
viewer_https_only Set this to false if you need to support insecure HTTP access for clients, in addition to HTTPS string "true" no

aws/aws_ec2_ebs_docker_host

aws_ec2_ebs_docker_host

Creates a standalone Docker host on EC2, optionally attaching an external EBS volume for persistent data.

This is convenient for quickly setting up non-production-critical Docker workloads. If you need something fancier, consider e.g. ECS, EKS or Fargate.

Example 1: Running a docker container

Assuming you have the AWS provider set up:

module "my_host" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_ec2_ebs_docker_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_ec2_ebs_docker_host?ref=v11.0"

  hostname             = "my-docker-host"
  ssh_private_key_path = "~/.ssh/id_rsa"     # if you use shared Terraform state, consider changing this to something that doesn't depend on "~"
  ssh_public_key_path  = "~/.ssh/id_rsa.pub"
  allow_incoming_http  = true                # by default, only incoming SSH is allowed; other protocols for the security group are opt-in
}

output "host_ssh_command" {
  description = "Run this command to create a port-forward to the remote docker daemon"
  value       = "ssh -i ${module.my_host.ssh_private_key_path} -o StrictHostKeyChecking=no -L localhost:2377:/var/run/docker.sock ${module.my_host.ssh_username}@${module.my_host.public_ip}"
}

After terraform apply, and running the host_ssh_command, you should be able to connect from your local Docker CLI to the remote daemon, e.g.:

$ DOCKER_HOST=localhost:2377 docker run -d -p 80:80 nginx

Visit the IP address of your host in a browser to make sure it works.

Example 2: Using a persistent data volume

Assuming you have the AWS provider set up:

resource "aws_ebs_volume" "my_data" {
  availability_zone = "${module.my_host.availability_zone}" # ensure the volume is created in the same AZ the docker host
  type              = "gp2"                                 # i.e. "Amazon EBS General Purpose SSD"
  size              = 25                                    # in GiB; if you change this in-place, you need to SSH over and run e.g. $ sudo resize2fs /dev/xvdh
}

module "my_host" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_ec2_ebs_docker_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_ec2_ebs_docker_host?ref=v11.0"

  hostname             = "my-host"
  ssh_private_key_path = "~/.ssh/id_rsa"                # note that with a shared Terraform state, paths with "~" will become problematic
  ssh_public_key_path  = "~/.ssh/id_rsa.pub"
  data_volume_id       = "${aws_ebs_volume.my_data.id}" # attach our EBS data volume
}

output "host_ssh_command" {
  description = "Run this command to check that the data volume got mounted"
  value       = "ssh -i ${module.my_host.ssh_private_key_path} -o StrictHostKeyChecking=no ${module.my_host.ssh_username}@${module.my_host.public_ip} df -h"
}

Note that due to a bug in Terraform, at the time of writing, you need to apply in two parts:

$ terraform apply -target aws_ebs_volume.my_data
...
$ terraform apply
...

Afterwards, running the host_ssh_command should give you something like:

Filesystem      Size  Used Avail Use% Mounted on
udev            481M     0  481M   0% /dev
tmpfs            99M  752K   98M   1% /run
/dev/xvda1      7.7G  2.1G  5.7G  27% /
tmpfs           492M     0  492M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           492M     0  492M   0% /sys/fs/cgroup
/dev/loop0       88M   88M     0 100% /snap/core/5328
/dev/loop1       13M   13M     0 100% /snap/amazon-ssm-agent/495
/dev/xvdh        25G   45M   24G   1% /data
tmpfs            99M     0   99M   0% /run/user/1000

That is, you can see the 25 GB data volume mounted at /data.

Example 3: Running additional provisioners

Assuming you have the AWS provider set up:

module "my_host" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_ec2_ebs_docker_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_ec2_ebs_docker_host?ref=v11.0"

  hostname             = "my-docker-host"
  ssh_private_key_path = "~/.ssh/id_rsa"
  ssh_public_key_path  = "~/.ssh/id_rsa.pub"
}

resource "null_resource" "provisioners" {
  depends_on = ["module.my_host"] # wait until other provisioners within the module have finished

  connection {
    host        = "${module.my_host.public_ip}"
    user        = "${module.my_host.ssh_username}"
    private_key = "${module.my_host.ssh_private_key}"
    agent       = false
  }

  provisioner "remote-exec" {
    inline = ["echo HELLO WORLD"]
  }
}

Example 4: Using the docker provider

Note that until direct support for the SSH protocol in the docker provider lands in Terraform, this is a bit cumbersome. But it's documented here in case it's useful.

Assuming you have the AWS provider set up:

module "my_host" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_ec2_ebs_docker_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_ec2_ebs_docker_host?ref=v11.0"

  hostname             = "my-docker-host"
  ssh_private_key_path = "~/.ssh/id_rsa"
  ssh_public_key_path  = "~/.ssh/id_rsa.pub"
  allow_incoming_http  = true
}

output "docker_tunnel_command" {
  description = "Run this command to create a port-forward to the remote docker daemon"
  value       = "ssh -i ${module.my_host.ssh_private_key_path} -o StrictHostKeyChecking=no -L localhost:2377:/var/run/docker.sock ${module.my_host.ssh_username}@${module.my_host.public_ip}"
}

provider "docker" {
  version = "~> 1.1"
  host    = "tcp://127.0.0.1:2377/" # Important: this is expected to be an SSH tunnel; see "docker_tunnel_command" in $ terraform output
}

resource "docker_image" "nginx" {
  name = "nginx"
}

resource "docker_container" "nginx" {
  image    = "${docker_image.nginx.latest}"
  name     = "nginx"
  must_run = true

  ports {
    internal = 80
    external = 80
  }
}

output "test_link" {
  value = "http://${module.my_host.public_ip}/"
}

Because the tunnel won't exist before the host is up, this needs to be applied with:

$ terraform apply -target module.my_host

This should finish by giving you the docker_tunnel_command output. Run that in another terminal, and then finish with another terraform apply. Afterwards, you should be able to visit the test_link and see nginx greeting you.

Inputs

Name Description Type Default Required
allow_incoming_dns Whether to allow incoming DNS traffic on the host security group string "false" no
allow_incoming_http Whether to allow incoming HTTP traffic on the host security group string "false" no
allow_incoming_https Whether to allow incoming HTTPS traffic on the host security group string "false" no
data_volume_id The ID of the EBS volume to mount as /data string "" no
hostname Hostname by which this service is identified in metrics, logs etc string "aws-ec2-ebs-docker-host" no
instance_ami See https://cloud-images.ubuntu.com/locator/ec2/ for options string "ami-0bdf93799014acdc4" no
instance_type See https://aws.amazon.com/ec2/instance-types/ for options; for example, typical values for small workloads are "t2.nano", "t2.micro", "t2.small", "t2.medium", and "t2.large" string "t2.micro" no
reprovision_trigger An arbitrary string value; when this value changes, the host needs to be reprovisioned string "" no
root_volume_size Size (in GiB) of the EBS volume that will be created and mounted as the root fs for the host string "8" no
ssh_private_key_path SSH private key file path, relative to Terraform project root string "ssh.private.key" no
ssh_public_key_path SSH public key file path, relative to Terraform project root string "ssh.public.key" no
ssh_username Default username built into the AMI (see 'instance_ami') string "ubuntu" no
swap_file_size Size of the swap file allocated on the root volume string "512M" no
swap_swappiness Swappiness value provided when creating the swap file string "10" no
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
vpc_id ID of the VPC our host should join; if empty, joins your Default VPC string "" no

Outputs

Name Description
availability_zone AWS Availability Zone in which the EC2 instance was created
hostname Hostname by which this service is identified in metrics, logs etc
instance_id AWS ID for the EC2 instance used
public_ip Public IP address assigned to the host by EC2
security_group_id Security Group ID, for attaching additional security rules externally
ssh_private_key SSH private key that can be used to access the EC2 instance
ssh_private_key_path Path to SSH private key that can be used to access the EC2 instance
ssh_username Username that can be used to access the EC2 instance over SSH

aws/aws_lambda_api

aws_lambda_api

This module creates a Lambda function, and makes it available via a custom domain, complete with SSL termination: e.g. https://api.example.com/. This includes:

  • DNS records on Route 53
  • An SSL certificate for the domain from ACM
  • API Gateway configuration for invoking the function over HTTP
  • A Lambda function built from your JavaScript code

Example 1: Simple API

First, write down some simple code to deploy in a file called index.js:

exports.handler = function(event, context, callback) {
  console.log("Lambda function event:", event);
  console.log("Lambda function context:", context);
  callback(null, {
    // See here for docs on this response object:
    // https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-output-format
    statusCode: 200,
    headers: { "Content-Type": "text/plain; charset=utf-8" },
    body: "Hello World!"
  });
};

Assuming you have the AWS provider set up, and a DNS zone for example.com configured on Route 53:

# Lambda functions can only be uploaded as ZIP files, so we need to package our JS file into one
data "archive_file" "lambda_zip" {
  type        = "zip"
  source_file = "${path.module}/index.js"
  output_path = "${path.module}/lambda.zip"
}

module "my_api" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_lambda_api#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_lambda_api?ref=v11.0"

  api_domain             = "api.example.com"
  lambda_logging_enabled = true

  # lambda_zip.output_path will be absolute, i.e. different on different machines.
  # This can cause Terraform to notice differences that aren't actually there, so let's convert it to a relative one.
  # https://github.com/hashicorp/terraform/issues/7613#issuecomment-332238441
  function_zipfile = "${substr(data.archive_file.lambda_zip.output_path, length(path.cwd) + 1, -1)}"
}

After terraform apply, you should be able to visit https://api.example.com/, and be greeted by the above Hello World! message.

Because we included the lambda_logging_enabled option, you can also log into CloudWatch and check out the properties Lambda makes available in the event and context properties.

The associated API Gateway has been configured to route all requests to our Lambda function. Try visiting https://api.example.com/foo/bar?baz=123 for instance, and you should get the same message, but with different parameters in the event object. This allows you to implement arbitrary routing rules in JavaScript, without having to define them in API Gateway also.

Example 2: Adding a build step

Say you want to do something non-trivial in your Lambda. This probably means installing some libraries from npm, and possibly writing the Lambda in TypeScript.

An example project is included with these docs. It demonstrates a simple workflow for:

  1. Compiling your Lambda function from TypeScript
  2. Including external dependencies from npm (the one-liner-joke package serves as an example)
  3. Releasing code changes via Terraform

Importantly, the most recent compiled version of the Lambda function should always exist in example-project/dist/lambda.zip, and be committed to version control. This seems counter to best practices, but otherwise developers who have just cloned your Terraform repo will be unable to e.g. terraform apply, before installing the full node toolchain locally, to be able to compile the Lambda function. The same applies to your CI server, for example. This may not be the correct workflow for larger projects, however; see below for suggestions in that regard.

Assuming you have the AWS provider set up, and a DNS zone for example.com configured on Route 53:

module "my_api" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_lambda_api#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_lambda_api?ref=v11.0"

  api_domain             = "api.example.com"
  lambda_logging_enabled = true
  function_zipfile       = "./path/to/example-project/dist/lambda.zip"
}

After terraform apply, you should be able to receive a random joke with:

$ curl https://api.example.com
{
  "body": "You look like a before picture.",
  "tags": [
    "insults"
  ]
}

Whenever you make changes to the function code, make sure you run build.sh again, commit the result, and then terraform apply to deploy your changes.

Example 3: Separating Lambda code from infra code

Bundling the code and build artifacts for your Lambda function is all well and good when you just want to get things done. However, for a larger or more active project, you're probably better off separating the JavaScript project for the Lambda function into a separate repository. In that case, the process usually looks something like this:

  1. Changes to the Lambda code are pushed to version control
  2. A CI process picks up the changes, builds the code into a zipfile
  3. The zipfile gets named with some versioning scheme, e.g. lambda-v123.zip
  4. The CI process uploads the zipfile into an S3 bucket
  5. The release is made by updating the Terraform config accordingly

This also makes it easy to support multiple environments, and release promotions between them. For example:

resource "aws_s3_bucket" "my_builds" {
  bucket = "my-builds"
}

module "my_api_stage" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_lambda_api#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_lambda_api?ref=v11.0"

  api_domain         = "api-stage.example.com"
  function_s3_bucket = "${aws_s3_bucket.my_builds.id}"
  function_zipfile   = "lambda-v123.zip"

  function_env_vars = {
    ENV_NAME = "stage"
  }
}

module "my_api_prod" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_lambda_api#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_lambda_api?ref=v11.0"

  api_domain         = "api-prod.example.com"
  function_s3_bucket = "${aws_s3_bucket.my_builds.id}"
  function_zipfile   = "lambda-v122.zip"

  function_env_vars = {
    ENV_NAME = "prod"
  }
}

You'll note how the stage environment is running the latest v123 release, while prod is still on the previous v122 release. Once the v123 release has been thoroughly tested on the stage environment, it can be promoted to prod by changing the function_zipfile variable, and issuing a terraform apply. This process supports immutable releases, easy rollbacks, and an audit trail of past releases.

Example 4: Releasing without Terraform

Sometimes it's convenient to let your CI perform the release unattended. One way to accomplish this is to use just function_zipfile = "lambda-stage.zip" and function_zipfile = "lambda-prod.zip" in your Terraform configuration, but then do something like this for releases to stage:

./build.sh
aws s3 cp ./dist/lambda.zip s3://my-builds/lambda-stage.zip
aws lambda update-function-code --function-name my-stage-function-name --s3-bucket my-builds --s3-key lambda-stage.zip

And then to promote the current stage to prod:

aws s3 cp s3://my-builds/lambda-stage.zip s3://my-builds/lambda-prod.zip
aws lambda update-function-code --function-name my-prod-function-name --s3-bucket my-builds --s3-key lambda-prod.zip

...or some variation thereof. You get the idea.

Debugging API Gateway

If something isn't working right with your API Gateway, set api_gateway_logging_level = "INFO". Additionally, you need to add the following global configuration for your API Gateway:

resource "aws_api_gateway_account" "this" {
  cloudwatch_role_arn = "${aws_iam_role.apigateway_cloudwatch_logging.arn}"
}

resource "aws_iam_role" "apigateway_cloudwatch_logging" {
  name = "apigateway-cloudwatch-logging"

  assume_role_policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "apigateway.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}
EOF
}

resource "aws_iam_role_policy" "apigateway_cloudwatch_logging" {
  name = "apigateway-cloudwatch-logging"
  role = "${aws_iam_role.apigateway_cloudwatch_logging.id}"

  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "logs:CreateLogGroup",
        "logs:CreateLogStream",
        "logs:DescribeLogGroups",
        "logs:DescribeLogStreams",
        "logs:PutLogEvents",
        "logs:GetLogEvents",
        "logs:FilterLogEvents"
      ],
      "Resource": "*"
    }
  ]
}
EOF
}

Otherwise API Gateway won't have permission to write logs to CloudWatch.

Supporting CORS

Your API can easily support CORS, if needed. For example:

// https://enable-cors.org/server_nginx.html
const CORS_HEADERS = {
  "Access-Control-Allow-Origin": "*",
  "Access-Control-Allow-Methods": "POST,OPTIONS,GET,PUT,PATCH,DELETE",
  "Access-Control-Allow-Headers": "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range",
  "Access-Control-Expose-Headers": "Content-Length,Content-Range",
};

exports.handler = function(event, context, callback) {
  console.log("Lambda function event:", event);
  console.log("Lambda function context:", context);
  if (event.httpMethod === "OPTIONS") { // this is (probably) a CORS preflight request
    callback(null, {
      statusCode: 200,
      headers: CORS_HEADERS,
    });
  } else { // this is a regular request
    callback(null, {
      statusCode: 200,
      headers: {
        ...CORS_HEADERS,
        "Content-Type": "application/json"
      },
      body: JSON.stringify({ Hello: "World!" }),
    });
  }
};

Inputs

Name Description Type Default Required
api_domain Domain on which the Lambda will be made available (e.g. "api.example.com") string n/a yes
api_gateway_cloudwatch_metrics When true, sends metrics to CloudWatch string "false" no
api_gateway_logging_level Either "OFF", "INFO" or "ERROR"; note that this requires having a CloudWatch log role ARN globally in API Gateway Settings string "OFF" no
comment_prefix This will be included in comments for resources that are created string "Lambda API: " no
function_env_vars Which env vars (if any) to invoke the Lambda with map <map> no
function_handler Instructs Lambda on which function to invoke within the ZIP file string "index.handler" no
function_runtime Which node.js version should Lambda use for this function string "nodejs8.10" no
function_s3_bucket When provided, the zipfile is retrieved from an S3 bucket by this name instead (filename is still provided via function_zipfile) string "" no
function_timeout The amount of time your Lambda Function has to run in seconds string "3" no
function_zipfile Path to a ZIP file that will be installed as the Lambda function (e.g. "my-api.zip") string n/a yes
lambda_logging_enabled When true, writes any console output to the Lambda function's CloudWatch group string "false" no
memory_size Amount of memory in MB your Lambda Function can use at runtime string "128" no
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed, for S3 bucket name compatibility) string "aws-lambda-api---" no
stage_name Name of the single stage created for the API on API Gateway string "default" no
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
throttling_burst_limit How many burst requests should the API process at most; see https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-request-throttling.html string "5000" no
throttling_rate_limit How many sustained requests per second should the API process at most; see https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-request-throttling.html string "10000" no

Outputs

Name Description
api_gw_invoke_url This URL can be used to invoke the Lambda through the API Gateway
function_name This is the unique name of the Lambda function that was created

aws/aws_lambda_cronjob

aws_lambda_cronjob

This module creates a Lambda function, and configures it to be invoked on a schedule.

Example 1: Simple cronjob

First, write down some simple code to deploy in a file called index.js:

exports.handler = function(event, context, callback) {
  console.log("Lambda function event:", event);
  console.log("Lambda function context:", context);
  callback(null);
};

Assuming you have the AWS provider set up:

# Lambda functions can only be uploaded as ZIP files, so we need to package our JS file into one
data "archive_file" "lambda_zip" {
  type        = "zip"
  source_file = "${path.module}/index.js"
  output_path = "${path.module}/lambda.zip"
}

module "my_cronjob" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_lambda_cronjob#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_lambda_cronjob?ref=v11.0"

  cronjob_name           = "my-cronjob"
  schedule_expression    = "rate(5 minutes)" # note: full cron expressions are also supported
  lambda_logging_enabled = true

  # lambda_zip.output_path will be absolute, i.e. different on different machines.
  # This can cause Terraform to notice differences that aren't actually there, so let's convert it to a relative one.
  # https://github.com/hashicorp/terraform/issues/7613#issuecomment-332238441
  function_zipfile = "${substr(data.archive_file.lambda_zip.output_path, length(path.cwd) + 1, -1)}"
}

After terraform apply, because we included the lambda_logging_enabled option, you can log into CloudWatch and check out the properties Lambda makes available in the event and context properties.

Example 2: Other options for deploying code

As this module is a close relative of aws_lambda_api, the other options for deploying code are equally applicable here.

Inputs

Name Description Type Default Required
comment_prefix This will be included in comments for resources that are created string "Lambda Cronjob: " no
cronjob_name Name which will be used to create your Lambda function (e.g. "my-important-cronjob") string n/a yes
function_env_vars Which env vars (if any) to invoke the Lambda with map <map> no
function_handler Instructs Lambda on which function to invoke within the ZIP file string "index.handler" no
function_runtime Which node.js version should Lambda use for this function string "nodejs8.10" no
function_s3_bucket When provided, the zipfile is retrieved from an S3 bucket by this name instead (filename is still provided via function_zipfile) string "" no
function_timeout The amount of time your Lambda Function has to run in seconds string "3" no
function_zipfile Path to a ZIP file that will be installed as the Lambda function (e.g. "my-cronjob.zip") string n/a yes
lambda_logging_enabled When true, writes any console output to the Lambda function's CloudWatch group string "false" no
memory_size Amount of memory in MB your Lambda Function can use at runtime string "128" no
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed, for S3 bucket name compatibility) string "aws-lambda-cronjob---" no
schedule_expression How often to run the Lambda (see https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html); e.g. "rate(15 minutes)" or "cron(0 12 * * ? *)" string "rate(60 minutes)" no
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no

Outputs

Name Description
function_name This is the unique name of the Lambda function that was created

aws/aws_mailgun_domain

aws_mailgun_domain

Uses the Terraform Mailgun provider to set up and verify a domain, so you can use Mailgun for sending email from it.

Example

Assuming you have the AWS provider set up, and a DNS zone for example.com configured on Route 53:

variable "mailgun_api_key" {
  description = "Your Mailgun API key"
}

variable "demo_email_address" {
  description = "Enter your email (e.g. me@gmail.com), so you'll get a copy-pasteable curl command for testing the API immediately"
}

# Configure the Mailgun provider
# https://www.terraform.io/docs/providers/mailgun/index.html
provider "mailgun" {
  version = "~> 0.1"
  api_key = "${var.mailgun_api_key}"
}

module "my_mailgun_domain" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_mailgun_domain#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_mailgun_domain?ref=v11.0"

  mail_domain   = "example.com"
  smtp_password = "SECRET SECRET SECRET"
}

output "demo_curl_command" {
  value = "curl -s --user 'api:${var.mailgun_api_key}' ${module.my_mailgun_domain.api_base_url}messages -F from='Demo <demo@${module.my_mailgun_domain.mail_domain}>' -F to='${var.demo_email_address}' -F subject='Hello' -F text='Testing, testing...'"
}

Note that due to a bug in Terraform, at the time of writing, you need to apply in two parts:

$ terraform apply -target module.my_mailgun_domain.mailgun_domain.this
...
$ terraform apply
...

After the terraform apply, you either need to wait a bit, or if you're impatient, log into your Mailgun control panel and manually trigger the DNS verification. If you're too quick, running the command given by demo_curl_command will give you something like:

{
  "message": "The domain is unverified and requires DNS configuration. Log in to your control panel to view required DNS records."
}

After Mailgun is happy with your DNS records, however, you should get something like:

{
  "id": "<20190401125249.1.XXXYYYZZZ@example.com>",
  "message": "Queued. Thank you."
}

...and you should receive the test email shortly.

Inputs

Name Description Type Default Required
mail_domain Domain which you want to use for sending/receiving email (e.g. "example.com") string n/a yes
smtp_password Password that Mailgun will require for sending out SMPT mail via this domain string n/a yes
spam_action See https://www.terraform.io/docs/providers/mailgun/r/domain.html#spam_action string "disabled" no
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
wildcard See https://www.terraform.io/docs/providers/mailgun/r/domain.html#wildcard string "false" no

Outputs

Name Description
api_base_url Base URL of the Mailgun API for your domain
mail_domain Domain which you want to use for sending/receiving email (e.g. "example.com")

aws/aws_reverse_proxy

aws_reverse_proxy

This module implements a website that proxies content from another server.

Main features:

  • DNS entries are created automatically
  • HTTPS enabled by default
  • HTTP Strict Transport Security supported

Optional features:

  • HTTP Basic Auth
  • Plain HTTP instead of HTTPS
  • Cache TTL overrides
  • Custom response headers sent to clients
  • Custom request headers sent to origin server
  • Static response status/body override

Resources used:

  • Route53 for DNS entries
  • ACM for SSL certificates
  • CloudFront for proxying requests
  • Lambda@Edge for transforming requests
  • IAM for permissions

About CloudFront operations

This module manages CloudFront distributions, and these operations are generally very slow. Your terraform apply may take anywhere from 10 minutes up to 45 minutes to complete. Be patient: if they start successfully, they almost always finish successfully, it just takes a while.

Additionally, this module uses Lambda@Edge functions with CloudFront. Because Lambda@Edge functions are replicated, they can't be deleted immediately. This means a terraform destroy won't successfully remove all resources on its first run. It should complete successfully when running it again after a few hours, however.

Examples

Some common use cases for this module are:

How CloudFront caching works

It's important to understand that CloudFront, by default, respects cache headers given by the origin, that is, the server it's proxying requests to.

Default cache behaviour

Consider an origin server that doesn't give any Cache-Control headers. Any changes you make to its responses will be reflected immediately on the CloudFront distribution. That's is because this module will by default not cache such objects at all. This is a sensible default, because the AWS default TTL for CloudFront is 24 hours, and for an origin that doesn't explicitly send Cache-Control headers, it's rarely the desired behaviour: your site will be serving stale content for up to 24 hours. Users will be sad, and engineers will be yelled at.

Having immediate updates on CloudFront is convenient, but the downside is that every request for every file will be forwarded to your origin, to make sure the CloudFront cache still has the latest version. This can increase request latency for users, and infrastructure costs for you.

Specifying cache lifetimes on the origin

Let's say we're serving static files from an S3 bucket. Using the official AWS CLI, you can specify cache lifetimes as your objects are uploaded:

aws s3 cp --cache-control=no-store,must-revalidate index.html "s3://my-bucket/"
aws s3 cp --cache-control=max-age=31536000 static/image-v123.jpg "s3://my-bucket/"

This will upload index.html so that CloudFront will never serve its content to a user, without first checking that it's not been updated on S3. However, image-v123.jpg will be uploaded with cache headers that allow CloudFront to keep its copy for that object forever (well, technically 1 year, which is the maximum recommended value for max-age; in practice CloudFront will probably evict it before that for other reasons).

The above is a good middle ground caching strategy, for when you want immediate updates for your HTML documents (e.g. index.html), but static assets (e.g. image-v123.jpg) can be cached for much longer. This means that for the HTML document itself, you won't get any boost from CloudFront, but as the browser starts downloading the various linked static assets, they can be served directly from the CloudFront edge location, which should be much closer to the user, geographically. When you need to update the linked image, instead of updating image-v123.jpg, you should instead upload image-v124.jpg, and update any links in index.html to point to the new version. This ensures that:

  1. Users will see the new document (including its updated images) immediately
  2. Users won't see an inconsistent version of the document, where the document content is updated, but it's still showing the old images

Overriding cache lifetimes on CloudFront

If your origin server doesn't give out sensible cache control headers, or you're just feeling lazy, this module supports overriding cache behaviour on CloudFront, effectively ignoring anything your origin says about caching objects.

That is, if you specify cache_ttl_override = 0 for your site, every object will always be fetched from the origin, for every request. Importantly, though, this won't invalidate objects that are already in the CloudFront cache with a longer TTL. If you have an object that's "stuck" in your cache and you can't shake it, the CloudFront feature you're looking for is file invalidation.

Conversely, if you specify cache_ttl_override = 300, every object will stay in CloudFront for 5 minutes, regardless of its cache headers. This can be a good performance boost for your site, since only 1 request per file per 5 minutes will need to go all the way to the origin, and all the others can be served immediately from the CloudFront edge location. Keep in mind the aforementioned warning about "inconsistent versions", however: each object has their own TTL counter, so index.html and image.jpg may update at different times in the cache, even if you update content at your origin at the same time.

Inputs

Name Description Type Default Required
add_response_headers Map of HTTP headers (if any) to add to outgoing responses before sending them to clients map <map> no
basic_auth_body When using HTTP Basic Auth, and authentication has failed, this will be displayed by the browser as the page content string "Unauthorized" no
basic_auth_password When non-empty, require this password with HTTP Basic Auth string "" no
basic_auth_realm When using HTTP Basic Auth, this will be displayed by the browser in the auth prompt string "Authentication Required" no
basic_auth_username When non-empty, require this username with HTTP Basic Auth string "" no
cache_ttl_override When >= 0, override the cache behaviour for ALL objects in the origin, so that they stay in the CloudFront cache for this amount of seconds string "-1" no
cloudfront_price_class CloudFront price class to use (100, 200 or "All", see https://aws.amazon.com/cloudfront/pricing/) string "100" no
comment_prefix This will be included in comments for resources that are created string "Reverse proxy: " no
default_root_object The object to return when the root URL is requested string "" no
lambda_logging_enabled When true, writes information about incoming requests to the Lambda function's CloudWatch group string "false" no
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed, for S3 bucket name compatibility) string "aws-reverse-proxy---" no
origin_custom_header_name Name of a custom header to send to the origin; this can be used to convey an authentication header to the origin, for example string "X-Custom-Origin-Header" no
origin_custom_header_value Value of a custom header to send to the origin; see origin_custom_header_name string "" no
origin_custom_port When > 0, use this port for communication with the origin server, instead of relevant standard port string "0" no
origin_url Base URL for proxy upstream site (e.g. "https://example.com/") string n/a yes
override_response_body Same as override_response_status string "" no
override_response_status When this and the other override_response_* variables are non-empty, skip sending the request to the origin altogether, and instead respond as instructed here string "" no
override_response_status_description Same as override_response_status string "" no
site_domain Domain on which the reverse proxy will be made available (e.g. "www.example.com") string n/a yes
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
viewer_https_only Set this to false if you need to support insecure HTTP access for clients, in addition to HTTPS string "true" no

Outputs

Name Description
cloudfront_id The ID of the CloudFront distribution that's used for hosting the content
site_domain Domain on which the site will be made available

aws/aws_static_site

aws_static_site

This module implements a website for hosting static content.

Main features:

  • DNS entries are created automatically
  • S3 bucket is created automatically
  • HTTPS enabled by default
  • HTTP Strict Transport Security supported
  • Direct access to the S3 bucket is prevented

Optional features:

  • HTTP Basic Auth
  • Plain HTTP instead of HTTPS
  • Cache TTL overrides
  • Custom response headers sent to clients
  • Creating the S3 bucket outside of this module and passing it in via variable

Resources used:

  • Route53 for DNS entries
  • ACM for SSL certificates
  • CloudFront for proxying requests
  • Lambda@Edge for transforming requests
  • IAM for permissions

About CloudFront operations

This module manages CloudFront distributions, and these operations are generally very slow. Your terraform apply may take anywhere from 10 minutes up to 45 minutes to complete. Be patient: if they start successfully, they almost always finish successfully, it just takes a while.

Additionally, this module uses Lambda@Edge functions with CloudFront. Because Lambda@Edge functions are replicated, they can't be deleted immediately. This means a terraform destroy won't successfully remove all resources on its first run. It should complete successfully when running it again after a few hours, however.

Example 1: Simple static site

Assuming you have the AWS provider set up, and a DNS zone for example.com configured on Route 53:

# Lambda@Edge and ACM, when used with CloudFront, need to be used in the US East region.
# Thus, we need a separate AWS provider for that region, which can be used with an alias.
# Make sure you customize this block to match your regular AWS provider configuration.
# https://www.terraform.io/docs/configuration/providers.html#multiple-provider-instances
provider "aws" {
  alias  = "us_east_1"
  region = "us-east-1"
}

module "my_site" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_static_site#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_static_site?ref=v11.0"

  site_domain = "hello.example.com"
}

resource "aws_s3_bucket_object" "my_index" {
  bucket       = "${module.my_site.bucket_name}"
  key          = "index.html"
  content      = "<pre>Hello World!</pre>"
  content_type = "text/html; charset=utf-8"
}

output "bucket_name" {
  description = "The name of the S3 bucket that's used for hosting the content"
  value       = "${module.my_site.bucket_name}"
}

After terraform apply (which may take a very long time), you should be able to visit hello.example.com, be redirected to HTTPS, and be greeted by the above Hello World! message.

You may (and probably will) want to upload more files into the bucket outside of Terraform. Using the official AWS CLI this could look like:

aws s3 cp --cache-control=no-store,must-revalidate image.jpg "s3://$(terraform output bucket_name)/"

After this, image.jpg will be available at https://hello.example.com/image.jpg.

Example 2: Basic Authentication

This module supports password-protecting your site with HTTP Basic Authentication, via a Lambda@Edge function.

Update the my_site module in Example 1 as follows:

module "my_site" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_static_site#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_static_site?ref=v11.0"

  site_domain = "hello.example.com"

  basic_auth_username = "admin"
  basic_auth_password = "secret"
}

After terraform apply (which may take a very long time), visiting hello.example.com should pop out the browser's authentication dialog, and not let you proceed without the above credentials.

Example 3: Custom response headers

This module supports injecting custom headers into CloudFront responses, via a Lambda@Edge function.

By default, the function only adds Strict-Transport-Security headers (as it significantly improves security with HTTPS), but you may need other customization.

For additional security hardening of your static site, update the my_site module in Example 1 as follows:

module "my_site" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_static_site#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_static_site?ref=v11.0"

  site_domain = "hello.example.com"

  add_response_headers = {
    "Strict-Transport-Security" = "max-age=63072000; includeSubdomains; preload"
    "Content-Security-Policy"   = "default-src 'none'; img-src 'self'; script-src 'self'; style-src 'self'; object-src 'none'"
    "X-Content-Type-Options"    = "nosniff"
    "X-Frame-Options"           = "DENY"
    "X-XSS-Protection"          = "1; mode=block"
    "Referrer-Policy"           = "same-origin"
  }
}

After terraform apply (which may take a very long time), visiting hello.example.com should give you these extra headers.

It's also possible to override existing headers. For example:

module "my_site" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/aws_static_site#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_static_site?ref=v11.0"

  site_domain = "hello.example.com"

  add_response_headers = {
    "Server" = "My Secret Origin Server"
  }
}

After terraform apply, checking with curl --silent -I https://hello.example.com | grep Server should give you My Secret Origin Server instead of the default AmazonS3.

Example 4: Using your own bucket

If you already have an S3 bucket that you want to use, you can provide e.g. bucket_override_name = "my-existing-s3-bucket" as a variable for this module.

When bucket_override_name is provided, an S3 bucket is not automatically created for you. Note that you're then also responsible for setting up a bucket policy allowing CloudFront access to the bucket contents.

How CloudFront caching works

It's important to understand how CloudFront caches the files it proxies from S3. Because this module is built on the aws_reverse_proxy module, everything its documentation says about CloudFront caching is relevant here, too.

Specifying cache lifetimes on S3

It's a good idea to specify cache lifetimes for files individually, as they are uploaded.

For example, to upload a file so that it's never cached by CloudFront:

aws s3 cp --cache-control=no-store,must-revalidate index.html "s3://$(terraform output bucket_name)/"

Alternatively, to upload a file so that CloudFront can cache it forever:

aws s3 cp --cache-control=max-age=31536000 static/image-v123.jpg "s3://$(terraform output bucket_name)/"

Learn more about effective caching strategies on CloudFront.

Inputs

Name Description Type Default Required
add_response_headers Map of HTTP headers (if any) to add to outgoing responses before sending them to clients map <map> no
basic_auth_body When using HTTP Basic Auth, and authentication has failed, this will be displayed by the browser as the page content string "Unauthorized" no
basic_auth_password When non-empty, require this password with HTTP Basic Auth string "" no
basic_auth_realm When using HTTP Basic Auth, this will be displayed by the browser in the auth prompt string "Authentication Required" no
basic_auth_username When non-empty, require this username with HTTP Basic Auth string "" no
bucket_override_name When provided, assume a bucket with this name already exists for the site content, instead of creating the bucket automatically (e.g. "my-bucket") string "" no
cache_ttl_override When >= 0, override the cache behaviour for ALL objects in S3, so that they stay in the CloudFront cache for this amount of seconds string "-1" no
cloudfront_price_class CloudFront price class to use (100, 200 or "All", see https://aws.amazon.com/cloudfront/pricing/) string "100" no
comment_prefix This will be included in comments for resources that are created string "Static site: " no
default_root_object The object to return when the root URL is requested string "index.html" no
lambda_logging_enabled When true, writes information about incoming requests to the Lambda function's CloudWatch group string "false" no
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed, for S3 bucket name compatibility) string "aws-static-site---" no
site_domain Domain on which the static site will be made available (e.g. "www.example.com") string n/a yes
tags AWS Tags to add to all resources created (where possible); see https://aws.amazon.com/answers/account-management/aws-tagging-strategies/ map <map> no
viewer_https_only Set this to false if you need to support insecure HTTP access for clients, in addition to HTTPS string "true" no

Outputs

Name Description
bucket_domain_name Full S3 domain name for the bucket used for hosting the content (e.g. "aws-static-site---hello-example-com.s3-website.eu-central-1.amazonaws.com")
bucket_name The name of the S3 bucket that's used for hosting the content (either auto-generated or externally provided)
cloudfront_id The ID of the CloudFront distribution that's used for hosting the content
site_domain Domain on which the static site will be made available

aws/aws_vpc_msk

tf-msk

Terraform deployment of an AWS VPC, MSK Cluster, (optional) ACM-PCA & MSK Client

Infrastructure Tests
Infrastructure Tests
Infrastructure Tests

aws/static_website_ssl_cloudfront_private_s3

Static website hosted using S3 and cloudfront with SSL support

Hosting static website using S3 is a very cost effective approach. Since, S3 website does not support SSL certificate, we use cloudfront for the same. In this example, we host the contents in a private S3 bucket which is used as the origin for cloudfront. We use cloudfront Origin-Access-Identity to access the private content from S3.

Architecture

Architecture

aws/wordpress_fargate

Wordpress on Fargate

This terraform example demonstrates how to run a scalable wordpress site. In this exmaple, we have tried to use serverless technologies as much as possible. Hence, we chose to run the site on fargate and are using Aurora serverless as DB.

Read more about this on the blog Terraform Recipe for WordPress on Fargate

AWS Services

We used the below AWS services in our example. The main motivation behind the selection of services is that we select as many serverless components as possible.

  • Fargate - for computing
  • Aurora Serverless - for database
  • EFS (Elastic File System) - for persistent data storage
  • Cloudfront - CDN

Terraform setup

Initialize terraform environment

terraform init -backend-config="bucket=<BUCKET_NAME>" -backend-config="profile=<AWS_PROFILE>" -backend-config="region=<AWS_REGION>"

Create environment

  AWS_SDK_LOAD_CONFIG=1 \
  TF_VAR_site_domain=<PUBLIC_DOMAIN> \
  TF_VAR_public_alb_domain=<INTERNAL_DOMAIN_FOR_ALB> \
  TF_VAR_db_master_username=<DB_MASTER_USERNAME> \
  TF_VAR_db_master_password="<DB_MASTER_PASSWORD>" \
  AWS_PROFILE=<AWS_PROFILE> \
  AWS_DEFAULT_REGION=<AWS_REGION> \
  terraform apply

Tear down

  AWS_SDK_LOAD_CONFIG=1 \
  TF_VAR_site_domain=<PUBLIC_DOMAIN> \
  TF_VAR_public_alb_domain=<INTERNAL_DOMAIN_FOR_ALB> \
  TF_VAR_db_master_username=<DB_MASTER_USERNAME> \
  TF_VAR_db_master_password="<DB_MASTER_PASSWORD>" \
  AWS_PROFILE=<AWS_PROFILE> \
  AWS_DEFAULT_REGION=<AWS_REGION> \
  terraform destroy

p.s. Instead of environment variables, you can obviously use .tfvar files for assigning values to terraform variables.

azure

Azure Examples

azure/azure_linux_docker_app_service

azure_linux_docker_app_service

This terraform example demonstrates how to create a container based Linux App Service with secret management and monitoring.

Features

  • Managed identity for authentication instead of credentials
  • Key vault references for accessing secrets from App Service
  • Email alerts for errors and failed availability checks
  • Random suffix for resources requiring globally unique name

Azure services

Architecture

Azure Container Registry

For storing container images

  • App Service pulls the image from the registry during deployment
  • Authentication using managed identity

Key Vault

For storing and accessing secrets

  • Access management using access policies

App Service plan & App Service

For hosting the application. App Service is created into the plan. If you have multiple App Services, it is possible to share the same plan among them.

  • The application's docker image is deployed from the container registry
  • Managed identity for accessing the Key Vault & Container registry
  • Deployment slot for high availability deploys
  • App service has a lot of settings that can be configured. See all of them here.

Application Insights

User for monitoring, metrics, logs and alerts.

  • The application should use Application Insights library (e.g. for Node.js) to instrument the application and integrate it with App Insights
  • Includes availability checks from multiple locations
  • Email alert for:
    • Failed availability checks
    • Responses with 5xx response code
    • Failed dependencies (e.g. database query or HTTP request fails)

Example usage

Prerequisites

  • Azure account and a service principal
  • Resource group
  • Terraform Azure Provider set up
module "my_app" {
  # Required
  resource_group_name = "my-resource-group"
  alert_email_address = "example@example.com"

  # Optional (with their default values)
  name_prefix            = "azure-app-example--"
  app_service_name      = "appservice"
  app_insights_app_type = "other"
  app_service_plan_tier = "PremiumV2"
  app_service_plan_size = "P1v2"
}

We can create rest of the resources with terraform apply.

An example of a Node.js application can be found in ./example-app directory.

Building an image and deploying to the App Service

Inputs

Name Description Type Default Required
resource_group_name Name of the resource group where the resources are deployed string yes
alert_email_address Email address where alerts are sent string yes
name_prefix Name prefix to use for objects that need to be created (only lowercase alphanumeric characters and hyphens allowed) string "azure-app-example--" no
app_service_name Name of the app service to be created. Must be globally unique string "appservice" no
app_insights_app_type Application insights application type string "other" no
app_service_plan_tier App service plan tier string "PremiumV2" no
app_service_plan_size App service plan size string "P1v2" no

azure/layers

Terraform Azure Layers example

Azure resources may take a long time to create. Sometimes Terraform fails to spot that some resource actually requires another resourc

azure/layers

e that has not been fully created yet. Layers help to ensure that all prerequisite resources for later ones are created before them.

Try it out

az login
terraform init
sh create.sh -auto-approve -var resource_name_prefix=${USER}trylayers

Clean up

sh destroy.sh ${USER}trylayers

Files

  • create.sh presents a simple hard-coded deployment run that ensures each layer is completed separately.
  • destroy.sh takes a quick, resource-group based approach to wiping out the whole deployment.
  • layers.tf lists each layer with associated dependencies.
  • main.tf contains sample resources used on different layers.
  • variables.sh declares associated variables with sane defaults.

generic

Generic Examles

generic/docker_compose_host

docker_compose_host

Provisions an existing host to run services defined in a docker-compose.yml file.

This is a convenient companion to aws_ec2_ebs_docker_host, though any Debian-like host reachable over SSH should work.

Changing the contents of your docker-compose.yml file (or any other variables defined for this module) will trigger re-creation of the containers on the next terraform apply.

Example

Assuming you have the AWS provider set up:

module "my_host" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/docker_compose_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//aws_ec2_ebs_docker_host?ref=v11.0"

  hostname             = "my-docker-host"
  ssh_private_key_path = "~/.ssh/id_rsa"
  ssh_public_key_path  = "~/.ssh/id_rsa.pub"
  allow_incoming_http  = true
  reprovision_trigger  = "${module.my_docker_compose.reprovision_trigger}"
}

module "my_docker_compose" {
  # Available inputs: https://github.com/futurice/terraform-utils/tree/master/docker_compose_host#inputs
  # Check for updates: https://github.com/futurice/terraform-utils/compare/v11.0...master
  source = "git::ssh://git@github.com/futurice/terraform-utils.git//docker_compose_host?ref=v11.0"

  public_ip          = "${module.my_host.public_ip}"
  ssh_username       = "${module.my_host.ssh_username}"
  ssh_private_key    = "${module.my_host.ssh_private_key}"
  docker_compose_yml = "${file("./docker-compose.yml")}"
}

output "test_link" {
  value = "http://${module.my_host.public_ip}/"
}

In your docker-compose.yml file, try:

version: "3"
services:
  nginx:
    image: nginx
    ports:
      - "80:80"

After a terraform apply, you should be able to visit the test_link and see nginx greeting you.

Any changes to the compose file trigger re-provisioning of the services. For example, try changing your services to:

version: "3"
services:
  whoami:
    image: jwilder/whoami
    ports:
      - "80:8000"

When running terraform apply, the previous nginx service will be stopped and removed, and then the new whoami service will be started in its stead. Visiting the test_link URL again should give you a different result now.

Inputs

Name Description Type Default Required
docker_compose_down_command Command to remove services with; will be run during un- or re-provisioning string "docker-compose stop 00260026 docker-compose rm -f" no
docker_compose_env Env-vars (in .env file syntax) that will be substituted into docker-compose.yml (see https://docs.docker.com/compose/environment-variables/#the-env-file) string "# No env-vars set" no
docker_compose_override_yml Contents for the docker-compose.override.yml file (see https://docs.docker.com/compose/extends/#multiple-compose-files) string `"# Any docker-compose services defined here will be merged on top of docker-compose.yml

See: https://docs.docker.com/compose/extends/#multiple-compose-files

version: "3" "| no | | docker_compose_up_command | Command to start services with; you can customize this to do work before/after, or to disable this completely in favor of your own provisioning scripts | string |"docker-compose pull --quiet 00260026 docker-compose up -d"| no | | docker_compose_version | Version of docker-compose to install during provisioning (see https://github.com/docker/compose/releases) | string |"1.23.2"| no | | docker_compose_yml | Contents for thedocker-compose.ymlfile | string | n/a | yes | | public_ip | Public IP address of a host running docker | string | n/a | yes | | ssh_private_key | SSH private key, which can be used for provisioning the host | string | n/a | yes | | ssh_username | SSH username, which can be used for provisioning the host | string |"ubuntu"` | no |

Outputs

Name Description
reprovision_trigger Hash of all docker-compose configuration used for this host; can be used as the reprovision_trigger input to an aws_ec2_ebs_docker_host module

google_cloud

Google Cloud Platform Examples

google_cloud/camunda-secure

Provisioning Camunda on Cloud Run + Cloud SQL, using Terraform and Cloud Build

Terraform receipe for running Camunda BPMN workflow engine serverlessly on Cloud Run, using Cloud SQL as the backing store. Custom image building offloaded to Cloud Build. Private container image hosting in Google Container Engine.

Customize the base image in the main.tf locals.

Read more on the blog

Terraform setup

Create service account credentials for running terraform locally. Then

export GOOGLE_CREDENTIALS=<PATH TO SERVICE ACCOUNT JSON CREDS>
gcloud auth activate-service-account --key-file $GOOGLE_CREDENTIALS
terraform init

Terraform service account, Editor role was not enough

  • to set cloud run service to noauth, had to add Security Admin on camunda cloud run resource (NOT PROJECT level)

Docker / gcloud Setup

For mac I needed to expose the docker deamon on a tcp port:-

docker run -d -v /var/run/docker.sock:/var/run/docker.sock -p 127.0.0.1:1234:1234 bobrik/socat TCP-LISTEN:1234,fork UNIX-CONNECT:/var/run/docker.sock

Then in bash_profile:

export DOCKER_HOST=tcp://localhost:1234

Also needed to setup GCR creds in docker

gcloud auth configure-docker

google_cloud/camunda

Provisioning Camunda on Cloud Run + Cloud SQL, using Terraform and Cloud Build

Terraform receipe for running Camunda BPMN workflow engine serverlessly on Cloud Run, using Cloud SQL as the backing store. Custom image building offloaded to Cloud Build. Private container image hosting in Google Container Engine.

Customize the base image in the main.tf locals.

Read more on the blog

Terraform setup

Create service account credentials for running terraform locally. Then

export GOOGLE_CREDENTIALS=<PATH TO SERVICE ACCOUNT JSON CREDS>
gcloud auth activate-service-account --key-file $GOOGLE_CREDENTIALS
terraform init

Terraform service account, Editor role was not enough

  • to set cloud run service to noauth, had to add Security Admin on camunda cloud run resource (NOT PROJECT level)

Docker / gcloud Setup

For mac I needed to expose the docker deamon on a tcp port:-

docker run -d -v /var/run/docker.sock:/var/run/docker.sock -p 127.0.0.1:1234:1234 bobrik/socat TCP-LISTEN:1234,fork UNIX-CONNECT:/var/run/docker.sock

Then in bash_profile:

export DOCKER_HOST=tcp://localhost:1234

Also needed to setup GCR creds in docker

gcloud auth configure-docker

google_cloud/CQRS_bigquery_memorystore

CQRS Bigquery Memorystore Timeseries Analytics with Self Testing Example

Read the blog Exporting Bigquery results to memorystore

# Bigquery #Memorystore #Cloud Functions #Cloud Scheduler #Pubsub #Cloud Storage

Getting started

export GOOGLE_CREDENTIALS=<PATH TO SERVICE ACCOUNT JSON CREDS>
gcloud auth activate-service-account --key-file $GOOGLE_CREDENTIALS
terraform init

Note you need to switch on the App Engine API (dependancy of Cloud Scheduler), choose wisely, this is irreversable. The region CANNOT be changed.

Tips

Shut down memorystore

terraform destroy -target module.memorystore.google_redis_instance.cache

google_cloud/minecraft

Economical Minecraft server

A safe Minecraft server that won't break the bank. Game data is preserved across sessions. Server is hosted on a permenant IP address. You need to start the VM each session, but it will shutdown within 24 hours if you forget to turn it off. Process is run in a sandboxed VM, so any server exploits cannot do any serious damage.

We are experimenting with providing support through a google doc.

Help us make this simple for others to use by asking for help.

Launch blog can be found here

Features

  • Runs itzg/minecraft-server Docker image
  • Preemtible VM (cheapest), shuts down automatically within 24h if you forget to stop the VM
  • Reserves a stable public IP, so the minecraft clients do not need to be reconfigured
  • Reserves the disk, so game data is remembered across sessions
  • Restricted service account, VM has no ability to consume GCP resources beyond its instance and disk
  • 2$ per month
    • Reserved IP address costs: $1.46 per month
    • Reserved 10Gb disk costs: $0.40
    • VM cost: $0.01 per hour, max session cost $0.24

google_cloud/oathkeeper

I was hoping to add an identity aware proxy to a Google Cloud Run endpoint using oathkeeper. However, as of 2020/05/02 there is not easy way to fetch a token from the metadata server and add it to an upstream header, required to make an authenticated call to a protected Cloud Run endpoint

google_cloud/openresty-beyondcorp

Swiss Army Identity Aware Proxy

Very fast Serverless OpenResty based proxy that can wrap upstream binaries with a login. Furthermore, we have examples of

  • Local development environment
  • Slack/Zapier intergration.
  • A Write Ahead Log
  • Google Secret Manager intergration

Read more on the OpenResty: a Swiss Army Proxy for Serverless; WAL, Slack, Zapier and Auth blog.

An earlier version is linked to in the Minimalist BeyondCorp style Identity Aware Proxy for Cloud Run blog that is just the login part.

OpenResty and Cloud Run

Build on top of OpenResty, hosted on Cloud Run (and excellent match)

Extensions Fast Response using a Write Ahead Log

If upstream is slow (e.g. scaling up), you can redirect to a WAL. Latency is the time to store the message. A different location plays back the WAL with retries so you can be sure the request is eventially handled.

Extensions Securing a Slack Intergration

Intergration with Slack Reads a secret from Google secrets manager and verifies the signature HMAC

Extensions Securing a Zapier Intergration

Zapier can be protected with an Oauth account

Local testing with docker-compose

Generate a local service account key in .secret

gcloud iam service-accounts keys create .secret/sa.json --iam-account=openresty@larkworthy-tester.iam.gserviceaccount.com

run this script to get a setup that reloads on CTRL + C

/bin/bash test/dev.sh

The use of bash to start the script gives it an easier name to find to kill

killall "bash"

Get prod tokens

https://openresty-flxotk3pnq-ew.a.run.app/login?token=true

Test WAL verification

curl -X POST -d "{}" http://localhost:8080/wal-playback/

Test token validation

curl http://localhost:8080/httptokeninfo?id_token=foo
curl http://localhost:8080/httptokeninfo?access_token=foo

Test slack

curl http://localhost:8080/slack/command

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Terraform samples for all the major clouds you can copy and paste. The future, co-created.

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