Notify a chat channel

plywood switches on chant’s notify.

notify:
  slack: { webhook: SLACK_WEBHOOK_URL }
  on: [wave-waiting, up-refused, up-failed, drift]

Each value names a variable; the URL itself never goes in plywood.yml. teams: { webhook: ... } does the same for Microsoft Teams, and webhook: { url: ..., key: ... } sends to any endpoint, each chant.notify/v1 event signed with the key under x-plywood-* headers. on lists the events to send, all four when left out. Every event carries source: plywood and a summary line in plywood’s words.

plywood drift sends one drift event per run that finds drift. The event names the drifted stacks and carries the run’s fingerprint. A run whose finding matches the last one sends nothing. The drift issues hold the last finding: with --forge, a run sends again only once a stack’s finding changes. A run that keeps no issues sends on every drift. The scheduled drift job maps each notify variable from the secret of the same name, as the waves workflow does.

Set relay to the variable holding a relay key, and a waiting wave’s Slack message gets Approve and Decline buttons. Its Teams card gets a reply that approves. plywood notify relay receives them and records the approval on the ledger.