SEC.01
The playbook
The run starts read-only: the recon probes decide what happens next. The steps that follow are adapted to the distribution and state found — a real machine is rarely clean.
- 01reconDocker present? daemon API version
- 02reconWatchtower already deployed? containrrr/watchtower image (archived, incompatible with Docker 29) to migrate?
- 03reconserver time zone (for the schedule)
- 04actSet the old Watchtower aside (only if it exists)verify
- 05actRun Watchtowerverify
SEC.02
What it verifies
Each step ships its own check. The run only moves on when the check passes, so what the recipe reports as done is what is actually on the server.
- 01verifySet the old Watchtower aside (only if it exists)Verified by
docker ps -a --filter name=^watchtower-old$ --format '{{.Status}}' - 02verifyRun WatchtowerVerified by
docker inspect -f '{{.State.Running}}' watchtower && docker logs watchtower 2>&1 | grep -ci 'too old'
SEC.03
Guardrails
Non-negotiable instructions the run must respect, whatever it finds on the server.
If Docker or the compose plugin is missing: stop and tell the user to run the "Docker Engine" recipe first (do not install it on the fly). Auto-updates restart containers, production included: warn that this is the expected behaviour; with "only labelled containers", only those carrying com.centurylinklabs.watchtower.enable=true are updated. Do not delete the old watchtower-old container: let the user do it.
SEC.04
Variables
What you choose before launching — the recipe fills in the rest.
| Name | Meaning |
|---|---|
| ${schedule} | Schedule (6-field cron) |
| ${label_only} | Only labelled containers |
SEC.05
How a recipe runs in Servor
Servor is zero-knowledge: the platform cannot execute anything on its own. When you launch this recipe, a run reads the reconnaissance, plans the steps and asks for your approval. Each approved command is signed by your browser — with a key the server never sees — then relayed verbatim to the agent, which verifies the signature locally before executing.
search by intent — type “firewall”, get ufw
- 01Read-only reconnaissance before any change
- 02Every command signed by your browser, approved by you
- 03Each step verified before the run moves on, every run kept in the history
SEC.06
Deploy on Servor button
Maintain Watchtower or a project that needs it? Put this button in your README or on your site: one click and your users install it on their own server.
Dark background
Light background[](https://servor.app/deploy/install-watchtower)SEC.07
More containers recipes
- 01Docker EngineDocker Engine + Compose from the official repository, service active, hello-world verified.
- 02Docker ComposeDocker Compose plugin (docker compose), installed and verified.
- 03PodmanPodman (daemonless containers, rootless capable), verified.
- 04PortainerPortainer CE (LTS) Docker management web UI, admin preconfigured.
- 05k3s (lightweight Kubernetes)Single-node k3s cluster. Destructive: configures networking and a container runtime.
Verified recipe
Run this recipe on your server
Connect a server, launch the recipe, and approve each step as Servor executes and verifies it. Free plan, no card required.