Populate a Store From Infrastructure You Already Deployed

Reference architectures live for years. By the time you wire up a store hook, most of what it should cover was already deployed — some of it before hooks existed, some of it by a process outside Atmos entirely. Store hooks only ran after apply. To get an existing VPC ID or subnet list into a store, you had to force a fresh apply, or fall back to a manual write with a cloud CLI.

The Problem

A kind: store hook reads a Terraform output and writes it to a configured store, so other components can read it back later with !store or !store.get. Before this change, the supported lifecycle events did not include output or refresh. Nothing fired when you just wanted to read a value from infrastructure that already exists.

That gap matters most for the infrastructure you're least likely to touch again soon: a production VPC someone applied by hand two years ago, or a reference architecture deployed before your organization adopted hooks at all. Backfilling a store from that infrastructure meant either re-running apply against something that didn't need to change, or writing the value into the store yourself, outside Atmos.

The Fix

Atmos now fires lifecycle hooks around atmos terraform output and atmos terraform refresh, the same way it already does for plan, apply, and test. A kind: store hook (or a type: store step run through the kind: step bridge) can bind to after.terraform.output instead of, or alongside, after.terraform.apply:

hooks:
  backfill:
    events: [after.terraform.output]
    kind: store
    name: prod/ssm
    outputs:
      vpc_id: .id

Running atmos terraform output vpc -s prod now reads the current state and writes vpc_id into the store — no apply required. before/after.terraform.refresh events fire the same way around atmos terraform refresh, for hooks that care about reconciling state with the real infrastructure rather than just reading it.

How to Use It

Scope a store hook to after.terraform.output to backfill values from infrastructure that's already running:

hooks:
  outputs:
    events: [after.terraform.output]
    kind: store
    name: prod/ssm
    outputs:
      vpc_id: .id
      private_subnet_ids: .private_subnet_ids

atmos terraform output vpc -s prod

Keep an existing after.terraform.apply hook untouched, or list both events on the same hook so it fires on either command:

hooks:
  outputs:
    events: [after.terraform.apply, after.terraform.output]
    kind: store
    name: prod/ssm
    outputs:
      vpc_id: .id

Get Involved

Try binding a store hook to after.terraform.output against infrastructure you didn't apply through Atmos. Tell us what's missing — an aggregate event for --affected/--all output runs, or another lifecycle command entirely. Open an issue or start a discussion at github.com/cloudposse/atmos.