Terramate meets Atlantis 🚀

initContainers:
  - args:
      - >-
        curl -L https://github.com/terramate-io/terramate/releases/download/v${TERRAMATE_VERSION}/terramate_${TERRAMATE_VERSION}_linux_x86_64.tar.gz | tar xz
    command:
      - sh
      - -c
    env:
      - name: TERRAMATE_VERSION
        value: 0.4.5
    image: curlimages/curl
    name: get-terramate
    volumeMounts:
      - mountPath: /home/curl_user/
        name: terramate
    workingDir: /home/curl_user/
  extraVolumes:
    - name: terramate
      emptyDir: {}
  extraVolumeMounts:
    - name: terramate
      mountPath: /usr/local/bin/terramate
      subPath: terramate
      readOnly: true

environment:
  ATLANTIS_REPO_CONFIG: /etc/atlantis/server-side-config.yaml
extraVolumes:
  - name: atlantis-server-side-config
    configMap:
      name: atlantis-server-side-config
extraVolumeMounts:
  - name: atlantis-server-side-config
    mountPath: /etc/atlantis/server-side-config.yaml
    subPath: server-side-config.yaml
    readOnly: true

apiVersion: v1
kind: ConfigMap
metadata:
  name: atlantis-server-side-config
  labels:
    # I deploy it with the Atlantis chart, so here is helm templating
    app: {{ .Chart.Name }}
    chart: {{ .Chart.Name }}-{{ .Chart.AppVersion }}
    release: {{ .Release.Name }}
    heritage: {{ .Release.Service }}
data:
  server-side-config.yaml: |
    repos:
    # this steps run before every workflow. 
    # So we will generate tf-code here
    - pre_workflow_hooks:
        # to run 'safeguards' terramate wants origin master 
        #   and some previous commits
        - run: |
            git config --add remote.origin.fetch +refs/heads/master:refs/remotes/origin/master
            git fetch --depth=1 origin master
            git fetch --depth=2
          description: Fetch origin master branch

        # this step is optional
        # I use .tm-run-order later to made Atlantis 
        #   to run plan/apply in a specified order
        # Also, I generate an atlantis.yaml config 
        #   with terramate too, so I exclude it from run order: 
        #   it's just a yaml, not tf-code
        - run: terramate list --run-order -c --no-tags atlantis -B origin/master > .tm-run-order
          description: Get changed stacks

        # And the obvious final step =)
        - run: terramate generate
          description: Generating tf code
      # some other options, offtopic
      id: github.com/XXX/YYY
      apply_requirements: [mergeable, approved, undiverged]
      delete_source_branch_on_merge: true

stack {
  name        = "atlantis"
  description = "atlantis"
  id          = "your-uniq-id"

  tags = [
    "atlantis"
  ]
}

generate_file "atlantis.yaml" {
  condition = (
    # I place it in the root repo dir so I want to avoid 
    #   file generation with child stacks, only with
    #   atlantis stack and with not empty .tm-run-order
    terramate.stack.name == "atlantis" && tm_length(let.run_order) > 0
  )

  lets {
    run_order = tm_try(
      tm_compact(tm_split("\n", tm_trim(tm_file(".tm-run-order"), "\n"))),
    [])
    # dirty magic to fill config options by my folder structure
    projects = [for x in let.run_order : {
      name = tm_replace(x, "/^terraform/(projectX/)?/", "")
      dir  = x
      autoplan = {
        # I want to trigger Atlantis for every project
        #   because I already know that every project 
        #   here is modified
        when_modified = (
          tm_substr(x, 0, 14) == "terraform/projectX/" ? ["../../../**/*"] : ["../**/*"]
        )
        enabled = false
      }
    }]
    config = {
      version        = 3
      automerge      = true
      parallel_plan  = false
      parallel_apply = false
      projects       = let.projects
    }
  }

  content = tm_yamlencode(let.config)
}