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An app can redeploy itself when its image tag moves to a new digest (the hash of the image’s contents). It suits apps that track a floating tag such as nginx:1 or myorg/api:stable. It is off by default, per app.

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How it works

Every enabled app is checked on the control plane’s interval (APP_IMAGE_UPDATE_INTERVAL, default 1h, any Go duration). A check asks the image’s registry for the tag’s current digest. If it differs from the digest the app runs, the app redeploys through the normal image deploy path, so it shows up in deploy history and rolls out with its configured strategy. A check is skipped, with the reason recorded, when the app:
  • was built from source (redeploy it from git instead)
  • is stopped
  • is inside a deploy freeze window
  • is in a protected environment (deploy it manually so it gets approved)
  • already has a deploy running

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Turn it on

Dashboard: open the app, then Deploys, and switch on Redeploy automatically when the tag moves. Check now runs one check on demand. CLI:
API: GET and PUT /api/v1/apps/{name}/auto-update, and POST /api/v1/apps/{name}/auto-update/check. Reading needs read, changing or checking needs deploy.

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Update on push

Instead of waiting for the interval, point your registry’s push webhook at a URL the control plane mints for the app. Dashboard: Create webhook URL on the same card. CLI: levelrail-cli apps auto-update webhook web. The URL is shown once and a new one replaces the old; the URL itself is the secret, so treat it like a password. It must be reachable by your registry (Docker Hub, Harbor and most others just POST to it). A webhook for an app that has not opted in, or with a wrong token, answers 404. Repeat deliveries within 30 seconds of a check are acknowledged and skipped. The check runs in the background and follows the same skip rules. A tag pinned by digest (image@sha256:...) never moves, so there is nothing to update.
Last modified on October 12, 2026