/runway

Simplify infrastructure/app testing/deployment

Primary LanguagePythonApache License 2.0Apache-2.0

Runway

Build Status

What?

A lightweight wrapper around linting (e.g. yamllint) & infrastructure deployment tools (e.g. CloudFormation, Terraform, Serverless) to ease management of per-environment configs & deployment.

Why?

Very simple configuration to:

  • Perform automatic linting/verification
  • Ensure deployments are only performed when an environment config is present
  • Define an IAM role to assume for each deployment
  • Wrangle Terraform backend/workspace configs w/ per-environment tfvars
  • Avoid long-term tool lock-in
    • runway is a simple wrapper around standard tools. It simply helps to avoid convoluted Makefiles / CI jobs

How?

Complete quickstart documentation, including Docker images, CloudFormation templates, and walkthrough can be found here

Basic Concepts

  • Modules:
    • A single-tool configuration of an application/component/infrastructure (e.g. a set of CloudFormation stacks to deploy a VPC, a Serverless app)
  • Regions:
    • AWS regions
  • Environments:
    • A Serverless stage, a Terraform workspace, etc.
    • Environments are determined automatically from:
      1. Git branches. We recommend promoting changes through clear environment branches (prefixed with ENV-). For example, when running a deployment in the ENV-dev branch dev will be the environment. The master branch can also be used as a special 'shared' environment called common (e.g. for modules not normally promoted through other environments).
      2. The parent folder name of each module. For teams with a preference or technical requirement to not use git branches, each environment can be represented on disk as a folder. Instead of promoting changes via git merges, changes can be promoted by copying the files between the environment folders. See the ignore_git_branch runway.yml config option.
        • The folder name of the module itself (not its parent folder) if the ignore_git_branch and current_dir runway.yml config config options are both used (see "Directories as Environments with a Single Module" in "Repo Structure").
      3. The DEPLOY_ENVIRONMENT environment variable.
  • Deployments:
    • Mappings of modules to regions, optionally with AWS IAM roles to assume
  • runway.yml:
    • List of deployments
    • When the CI environment variable is set, all deployments are run in order; otherwise, the user is prompted for deployments to run.

Repo Structure

Git Branches as Environments

Sample repo structure, showing 2 modules using environment git branches (these same files would be present in each environment branch, with changes to any environment promoted through branches):

.
├── myapp.cfn
│   ├── dev-us-west-2.env
│   ├── prod-us-west-2.env
│   ├── myapp.yaml
│   └── templates
│       └── foo.json
├── myapp.tf
│   ├── backend.tfvars
│   ├── dev-us-east-1.tfvars
│   ├── prod-us-east-1.tfvars
│   └── main.tf
└── runway.yml

Directories as Environments

Another sample repo structure, showing the same modules nested in environment folders:

.
├── dev
│   ├── myapp.cfn
│   │   ├── dev-us-west-2.env
|   │   ├── prod-us-west-2.env
│   │   ├── myapp.yaml
│   │   └── templates
│   │       └── myapp_cf_template.json
│   ├── myapp.tf
│   │   ├── backend.tfvars
│   │   ├── dev-us-east-1.tfvars
|   │   ├── prod-us-east-1.tfvars
│   │   └── main.tf
│   └── runway.yml
└── prod
    ├── myapp.cfn
    │   ├── dev-us-west-2.env
    │   ├── prod-us-west-2.env
    │   ├── myapp.yaml
    │   └── templates
    │       └── myapp_cf_template.json
    ├── myapp.tf
    │   ├── backend.tfvars
    │   ├── dev-us-east-1.tfvars
    │   ├── prod-us-east-1.tfvars
    │   └── main.tf
    └── runway.yml

Directories as Environments with a Single Module

Another sample repo structure, showing environment folders containing a single CloudFormation module at their root (combining the current_dir & ignore_git_branch "Runway Config File" options to merge the Environment & Module folders):

.
├── dev
│   ├── dev-us-west-2.env
│   ├── prod-us-west-2.env
│   ├── myapp.yaml
│   ├── runway.yml
│   └── templates
│       └── myapp_cf_template.json
└── prod
    ├── dev-us-west-2.env
    ├── prod-us-west-2.env
    ├── myapp.yaml
    ├── runway.yml
    └── templates
        └── myapp_cf_template.json

Runway Config File

runway.yml example:

---
# Order that modules will be deployed. A module will be skipped if a
# corresponding env/config file is not present in its folder.
# (e.g., for cfn modules, if a dev-us-west-2.env file is not in the 'app.cfn'
# folder when running a dev deployment of 'app' to us-west-2 then it will be
# skipped.)
deployments:
  - modules:
      - myapp.cfn
    regions:
      - us-west-2
  - modules:
      - myapp.tf
    regions:
      - us-east-1
    assume-role:  # optional
      # When running multiple deployments, post_deploy_env_revert can be used
      # to revert the AWS credentials in the environment to their previous
      # values
      # post_deploy_env_revert: true
      dev: arn:aws:iam::account-id1:role/role-name
      prod: arn:aws:iam::account-id2:role/role-name
      # A single ARN can be specified instead, to apply to all environments
      # arn: arn:aws:iam::account-id:role/role-name
      # Role duration can be set at the top level, or in a specific environment
      # duration: 7200
      # dev:
      #   arn: arn:aws:iam::account-id1:role/role-name
      #   duration: 7200
    account-alias:  # optional
      # A mapping of environment -> alias mappings can be provided to have
      # Runway verify the current assumed role / credentials match the
      # necessary account
      dev: my_dev_account
      prod: my_dev_account
    account-id:  # optional
      # A mapping of environment -> id mappings can be provided to have Runway
      # verify the current assumed role / credentials match the necessary
      # account
      dev: 123456789012
      prod: 345678901234
    skip-npm-ci: false  # optional, and should rarely be used. Omits npm ci
                        # execution during Serverless deployments
                        # (i.e. for use with pre-packaged node_modules)

# If using environment folders instead of git branches, git branch lookup can
# be disabled entirely (see "Repo Structure")
# ignore_git_branch: true

runway.yml can also be placed in a module folder (e.g. a repo/environment containing only one module doesn't need to nest the module in a subfolder):

---
# This will deploy the module in which runway.yml is located
deployments:
  - current_dir: true
    regions:
      - us-west-2
    assume-role:
      arn: arn:aws:iam::account-id:role/role-name

# If using environment folders instead of git branches, git branch lookup can
# be disabled entirely (see "Repo Structure"). See "Directories as Environments
# with a Single Module" in "Repo Structure".
# ignore_git_branch: true

Installation

  • Install Python 2
    • On Linux (assuming default Bash shell; adjust for others appropriately):
      • Setup your shell for user-installed (non-root) pip packages:
        • echo 'export PATH=$HOME/.local/bin:$PATH' >> ${HOME}/.bashrc
        • source ${HOME}/.bashrc
      • Install Python/pip:
        • Debian-family (e.g. Ubuntu): sudo apt-get -y install python-pip python-minimal
        • Amazon Linux should should work out of the box
        • RHEL-family:
          • If easy_install is available: easy_install --user pip
          • Otherwise, enable EPEL and sudo yum install python-pip
    • On macOS (assuming default Bash shell; adjust for others appropriately):
      • if ! which pip > /dev/null; then easy_install --user pip; fi
      • echo 'export PATH="${HOME}/Library/Python/2.7/bin:${PATH}"' >> ${HOME}/.bash_profile
      • source ${HOME}/.bash_profile
    • On Windows:
      • This can be done via the Chocolately package manager (e.g. choco install python2), or manually from their website
        • If installing via Chocolately, default options will be sufficient. Close/reopen terminals after installation to use the updated PATH
        • If installing manually, use the default options with the exception of the "Add python to Path" (it should be enabled).
      • Add %USERPROFILE%\AppData\Roaming\Python\Scripts to PATH environment variable
  • Install runway (doesn't require sudo/admin permissions):
    • pip install --user runway
      • If this produces an error like Unknown distribution option: 'python_requires', upgrade setuptools first pip install --user --upgrade setuptools

Use

  • runway test (aka runway preflight) - execute this in your environment to catch errors; if it exits 0, you're ready for...
  • runway plan (aka runway taxi) - this optional step will show the diff/plan of what will be changed. With a satisfactory plan you can...
  • runway deploy (aka runway takeoff) - if running interactively, you can choose which deployment to run; otherwise (i.e. on your CI system) each deployment will be run in sequence.

Removing Deployments

  • runway destroy (aka runway dismantle) - if running interactively, you can choose which deployment to remove; otherwise (i.e. on your CI system) every deployment will be run in reverse sequence (use with caution).

Module Configurations

CloudFormation

CloudFormation modules are managed by 2 files: a key/value environment file, and a yaml file defining the stacks/templates/params.

Environment - name these in the form of ENV-REGION.env (e.g. dev-us-east-1.env) or ENV.env (e.g. dev.env):

# Namespace is used as each stack's prefix
# We recommend an (org/customer)/environment delineation
namespace: contoso-dev
environment: dev
customer: contoso
region: us-west-2
# The stacker bucket is the S3 bucket (automatically created) where templates
# are uploaded for deployment (a CloudFormation requirement for large templates)
stacker_bucket_name: stacker-contoso-us-west-2

Stack config - these can have any name ending in .yaml (they will be evaluated in alphabetical order):

# Note namespace/stacker_bucket_name being substituted from the environment
namespace: ${namespace}
stacker_bucket: ${stacker_bucket_name}

stacks:
  myvpcstack:  # will be deployed as contoso-dev-myvpcstack
    template_path: templates/vpc.yaml
    # The enabled option is optional and defaults to true. You can use it to
    # enable/disable stacks per-environment (i.e. like the namespace
    # substitution above, but with the value of either true or false for the
    # enabled option here)
    enabled: true
  myvpcendpoint:
    template_path: templates/vpcendpoint.yaml
    # variables map directly to CFN parameters; here used to supply the
    # VpcId output from the myvpcstack to the VpcId parameter of this stack
    variables:
      VpcId: ${output myvpcstack::VpcId}

The config yaml supports many more features; see the full Stacker documentation for more detail (e.g. stack configuration options, additional lookups in addition to output (e.g. SSM, DynamoDB))

Serverless

Standard Serverless rules apply, with the following recommendations/caveats:

  • Runway environments map directly to Serverless stages.
  • A package.json file is required, specifying the serverless dependency, e.g.:
{
  "name": "mymodulename",
  "version": "1.0.0",
  "description": "My serverless module",
  "main": "handler.py",
  "devDependencies": {
    "serverless": "^1.25.0"
  },
  "author": "Serverless Devs",
  "license": "ISC"
}
  • We strongly recommend you commit the package-lock.json that is generated after running npm install
  • Each stage requires its own variables file (even if empty for a particular stage), in one of the following forms:
env/STAGE-REGION.yml
config-STAGE-REGION.yml
env/STAGE.yml
config-STAGE.yml
env/STAGE-REGION.json
config-STAGE-REGION.json
env/STAGE.json
config-STAGE.json

Terraform

Standard Terraform rules apply, with the following recommendations/caveats:

  • Each environment requires its own tfvars file, in the form of ENV-REGION.tfvars (e.g. dev-contoso.tfvars).
  • We recommend (but do not require) having a backend configuration separate from the terraform module code:

main.tf:

terraform {
  backend "s3" {
    key = "some_unique_identifier_for_my_module" # e.g. contosovpc
  }
}
# continue with code here...

backend-REGION.tfvars, or backend-ENV-REGION.tfvars, or backend-ENV.tfvars (e.g. backend-us-east-1.tfvars):

bucket = "SOMEBUCKNAME"
region = "SOMEREGION"
dynamodb_table = "SOMETABLENAME"

tfenv

If a .terraform-version file is placed in the module, tfenv will be invoked to ensure the appropriate version is installed prior to module deployment.

Additional Functionality

whichenv

Execute runway whichenv to output the name of the currently detected environment (see Basic Concepts for an overview of how runway determines the environment name).