brock 1.0

A collection of Terraform-based blueprints

Bedrock - Building blocks for composable Cloud architectures

Table of Contents

1. Introduction - What is Bedrock?
2. Features
3. Getting started - How to use Bedrock
   • Requirements
   • Configuring
   • Examples - common usage scenarios
4. Development - Guide for contributing to the Bedrock project
   • Contributing to Bedrock

Introduction

Bedrock is a collection of blueprints for building public Cloud infrastructure using best-practice architectures and techniques. These blueprints are based on popular tools such as Terraform and Cloudformation, and provide both an informative and practical approach to infrastructure provisioning.

Blueprint

Manifest

A manifest provides a way to define one or more collections of blueprints (a constellation) and associated configurations that make up a complete architecture.

Often a single blueprint is not sufficient to define a Cloud architecture as they are more likely to be distributed across multiple services. For example, you might have an ECS cluster for web/API applications, RDS or DynamDB for persistence, and S3 for archiving.

Within each of these tiers are additional ancillary services such as route53 for well-known endpoints and/or service discovery, cloudwatch events/triggers, etc. The collection of blueprints that encapsulates and independent function is called a constellation. Multiple constellations may be defined in a single manifest such that an entire architecture may be provisioned.

A manifest also provides a higher-order language that can be used to unambiguously describe novel Cloud architectures that are composed of well-defined blueprints.

Features

The purpose of Bedrock is not only to provide best-practice blueprints for modern architectures, but to explore and educate about the challenges, decisions and opinions behind the designs themselves. As such, Bedrock aims to avoid a "black box" approach and is designed to encourage hacking and examining the underlying code.

Exploration

Each Bedrock module is designed to exist independently from the rest, to allow maximum portability and sharing of code. You can go into any module directory and run terraform init && terraform apply to execute a blueprint in your configured environment.

For example, if you require a Bastion host in your AWS account, do the following:

# provision IAM roles for creating Bastion host
cd terraform/blueprints/bastion/roles
terraform init && terraform apply

# provision a new Bastion EC2 host
cd ../aws
terraform init && terraform apply -var bastion_user=bedrock   

Run Anywhere

You can also build any Bedrock module as a Docker image, that can be run anywhere Docker is supported. Building images is supported via a Makefile in the root directory, which you can execute as follows:

# Build Docker images for Bastion roles and instance
make bastion-roles bastion-aws

The Makefile will ensure dependencies are build in the right order, and includes support for tagging and push to a remote Docker registry:

# Tag and push to AWS ECR
REGISTRY=<aws_account_id>.dkr.ecr.ap-southeast-2.amazonaws.com make tag push bastion-aws

After building an image you can now use the provided scripts to execute the blueprint in the current working directory:

# provision a new Bastion EC2 host
export BEDROCK_REGISTRY=<aws_account_id>.dkr.ecr.ap-southeast-2.amazonaws.com
bastion/scripts/bastion-aws.sh init && bastion/scripts/bastion-aws.sh apply

Automation

As the Docker images for Bedrock blueprints can be run anywhere that supports Docker, it is now possible to integrate with automated deployment and provisioning tools also. This might include build tools such as Jenkins or Bamboo, and also integrated with Cloud platforms such as AWS via the AWS Developer Tools (CodeBuild, CodePipeline, etc.).

As an example, we might configure a CodeBuild project to provision a blueprint using configuration from an S3 Bucket. Using S3 Bucket notifications we can trigger a build by simply updating a blueprint configuration. This allows for a very minimal effort approach to provisioning sophisticated and secure architectures whilst retaining the ability to maintain and evolve the designs.

Getting started

Examples

1. Provision a Bastion host

The following manifest file describes how to deploy an EC2 instance as a Bastion host:

name: AWS Bastion Host

description: Provision an EC2 instance for Bastion

constellations:
  bastion:
    bastion-roles:
    bastion-aws:
      bastion_user: fortuna

You can execute this file as follows:

$ bedrock apply -m bastion.yml -c ssh_key=@~/.ssh/id_rsa.pub

This command will apply the manifest in your AWS account, overriding the ssh_key input variable using the public SSH key from your local SSH configuration.

2. Deploy Lambda Layers

The following manifest will create common Lambda Layers for use in Lambda functions:

name: Lambda Layers

description: Create Lambda Layers to support Bedrock Lambda blueprints

constellations:
  aws-java-sdk-lambda:
    lambda-layer:
      layer_name: aws-java-sdk-lambda
      description: Support for the AWS Lambda SDK for Java
      content_path: /tools/aws-java-sdk-lambda/build/layer
      runtimes:
        - java8

  groovy-runtime:
    lambda-layer:
      layer_name: groovy-runtime
      description: Support for the Groovy JVM language
      content_path: /tools/groovy-runtime/build/layer
      runtimes:
        - java8

  python-requests:
    lambda-layer:
      layer_name: python-requests
      description: Python requests package plus dependencies
      content_path: /tools/python-requests/packages
      runtimes:
        - python3.6

Note that this manifest requires an additional volume to provide input for the content_path variable:

$ bedrock apply -m lambda-layers.yml -v "$PWD/tools:/tools"

Requirements

To make use of Bedrock you must have access to a public Cloud and a local environment with Docker installed.

If you intend to build the Docker images from source you will also require make to be installed.

Configuring

Configuration will depend on the Cloud environment(s) available, but typically will involve setting an API key in your environment that allows Terraform access to resources in your account.

When using API keys we want to restrict access to the bare minimum required to perform the required tasks (Principle of least privilege). As such you should ensure the associated user has just the permissions outlined in the table below:

Cloud Provider	Service	Permission
AWS	Codebuild	Execute
Digital Ocean	API	Full access

Terraform

You can manage your Terraform state using either local storage or with an AWS S3 bucket. It is advisable to use S3 to protect your state, in which case you will require a user with the following IAM permissions:

IAM Permission	Description	ARN
S3 Bucket create	Creates an S3 bucket containing Terraform state	arn:aws:iam::<AWS account ID>:policy/bedrock-terraform-state
IAM Policy create	Creates an IAM policy to allow access to read/write to the S3 Bucket	arn:aws:iam::<AWS account ID>:policy/bedrock-terraform-state

AWS

For provisioning blueprints in AWS you will require a user with the following IAM permissions:

IAM Permission	Description	ARN
Terraform state (*)	Read/write permissions to S3 bucket containing Terraform state	arn:aws:iam::<AWS account ID>:policy/bedrock-terraform-state
Assume role	Can assume role required for blueprint provisioning	arn:aws:iam::<AWS account ID>:role/-bedrock-

• Note that the Terraform state permission is only required when state is stored in AWS.

Development

Building Docker images

If you want to build the blueprint Docker images locally a Makefile is provided that supports the following goals:

# Build all blueprints with the default settings
make all 

# Build a specific set of blueprints    
make <blueprint> [<blueprint>...]

# Build blueprints with a specific Terraform version
BUILD_ARGS="--build-arg TERRAFORM_VERSION=0.11.4" make all    

# Generate documentation (README) for all blueprints
make docs

# Tag and push blueprints to a custom registry
REGISTRY="https://my.docker.registry/bedrock" make tag push 

Contributing

Open source software is made stronger by the community that supports it. Through participation you not only contribute to the quality of the software, but also gain a deeper insight into the inner workings.

Contributions may be in the form of feature enhancements, bug fixes, test cases, documentation and forum participation. If you have a question, just ask. If you have an answer, write it down.

And if you are somehow constrained from participation, through corporate policy or otherwise, consider financial support. After all, if you are profiting from open source it's only fair to give something back to the community that make it all possible.

Developer Environment

Use the following tools to provision a pre-configured developer environment.

Vagrant

$ vagrant up
$ ssh -p 2222 -L 8080:localhost:8080 vagrant@localhost  # password: vagrant

Docker

$ docker build -t bedrock-env .
$ ./developer-env.sh