tfvars-atlantis-config/README.md

tfvars-atlantis-config

tfvars pre-workflow hook for Atlantis

Quick start

CLI

tfvars-atlantis-config generate --automerge --autoplan --parallel --output=atlantis.yaml

Atlantis Server Side Config

repos:
- id: /.*/
  pre_workflow_hooks:
    - run: tfvars-atlantis-config generate --automerge --autoplan --parallel --output=atlantis.yaml

What is tfvars-atlantis-config?

Heavily inspired by terragrunt-atlantis-config, this tool allows you to dynamically generate your Atlantis configuration using tfvars instead of environment hiearchies.

This is useful for teams that have simple Terraform components and don't want the added complexity of using Terragrunt or structured environment levels.

Example

The following repo structure:

my-terraform
├── main.tf
├── dev.tfvars
├── prod.tfvars

Generates the following Atlantis configuration:

version: 3
automerge: true
parallel_plan: true
parallel_apply: true
projects:
- name: my-terraform-dev
  dir: my-terraform
  workflow: my-terraform-dev
  autoplan:
    when_modified:
    - '*.tf'
    - dev.tfvars
    enabled: true
- name: my-terraform-prod
  dir: my-terraform
  workflow: my-terraform-prod
  autoplan:
    when_modified:
    - '*.tf'
    - prod.tfvars
    enabled: true
workflows:
  my-terraform-dev:
    plan:
      steps:
      - init
      - plan:
          extra_args:
          - -var-file=dev.tfvars
    apply:
      steps:
      - apply
  my-terraform-prod:
    plan:
      steps:
      - init
      - plan:
          extra_args:
          - -var-file=prod.tfvars
    apply:
      steps:
      - apply

Why you should use it?

Dynamically generate your Atlantis configuration based on your Terraform components' .tfvars files:

• Auto plan per environment based on the environment .tfvars file modified.
• Auto plan all environments when a component's Terraform code is modified (*.tf).
• Allow your teams to organize their Terraform components in monorepos/standalone repositories how they want, while abstracting the configuration of Atlantis away from them, and reducing bloat in your repos.

Flags

Customize the behavior of this utility through CLI flag values passed in at runtime.

Flag Name	Description	Default Value
--automerge	Enable auto merge.	false
--autoplan	Enable auto plan.	false
--default-terraform-version	Default terraform version to run for Atlantis. Default is determined by the Terraform version constraints.	""
--debug	Enable debug logging.	false
--multienv	Enable injection of environment specific environment variables to each workflow.	false
--output	Path of the file where configuration will be generated, usually atlantis.yaml. Default is to write to stdout	stdout
--parallel	Enables plans and applys to happen in parallel.	false
--root	Path to the root directory of the git repo you want to build config for. Default is current dir.	.
--use-workspaces	Whether to use Terraform workspaces for projects.	false

Multienv

When --multienv is enabled, prefixed environment variables will be stripped of their prefix and injected into each workflow for the duration the workflow is run during plan/apply stages.

Example

dev.tfvars:

• DEV_FOO_VAR="BAR" -> FOO_VAR="BAR"
• DEV_AWS_ACCESS_KEY="..." -> AWS_ACCESS_KEY="..."

stg.tfvars:

• STG_FOO_VAR="BAR" -> FOO_VAR="BAR"
• STG_AWS_ACCESS_KEY="..." -> AWS_ACCESS_KEY="..."

..and so on.

Reference: Multienv