Disaster Recovery (lo recover)

lo recover <domain> rebuilds a cluster from bare metal back to a working Kubernetes cluster: it reimages the nodes in place (IPs, network, and load-balancer preserved), then runs a fresh lo provision. It is the foundation that a disaster recovery stands on: it restores the cluster, not the application data (etcd snapshots, databases, PVs restore on top of a recovered cluster; see Backups).

It supersedes hand-rolled, per-cluster DR scripts: rather than re-implementing teardown/rescue/reset/provision by hand, lo recover orchestrates the pieces the framework already owns: the provider's provider::rebuild node reset, lo provision (including the bare-metal #wipe-devices data-disk wipe), and the read-only lo doctor provider diagnosis.

The flow

resolve → doctor → consent → rebuild → provision → verify

1. resolve: resolve the domain's cluster spec, require it is a cluster domain (not a deploy domain), load its provider, and require the provider implements the provider::rebuild hook. A provider without it can't be auto-recovered in place, so lo recover stops here with a clear message.
2. doctor: print the provider's read-only infrastructure diagnosis (the same one lo doctor renders) before anything destructive: credentials and API reachability, the rescue SSH key, per-node installed-vs-rescue state, inventory sanity. This is advisory: it never blocks (enforcement is the rebuild's own preflight).
3. consent: a destructive-consent prompt naming the cluster and node count. This is the guard. --force (global) or LOK8S_NONINTERACTIVE=1 opt out of the prompt; declining touches nothing.
4. rebuild: provider::rebuild resets the cluster's existing nodes from bare metal (cloud VMs reimaged via hcloud server rebuild; bare-metal nodes booted into the Robot rescue system). It runs an atomic preflight that validates every declared node up front and touches nothing if any node fails. On failure lo recover stops: it will not provision on a half-reset cluster.
5. provision: a fresh lo provision (KubeOne/CAPI install). The bare-metal path runs the #wipe-devices data-disk wipe transparently.
6. verify: compare Ready nodes (kubectl) to the inventory count (provider::output), reporting each node's readiness.

Each phase is timed; the run ends with a per-phase summary (DONE in XmYs — phases: resolve=… doctor=… rebuild=… provision=… verify=…).

Usage

lo recover <domain>                 # full recovery (prompts once to confirm)
lo recover <domain> --dry-run       # preview: print the rebuild plan, change nothing
lo recover <domain> --skip-rebuild  # re-provision + verify only (nodes already reset)
lo recover <domain> --force         # skip the confirmation prompt (non-interactive)

Flag	Description
--domain <domain>	Flag form of the target domain (the positional wins when both are given; default: the active domain).
--dry-run	Run the read-only doctor + the provider::rebuild plan (reimages nothing), print that lo provision would follow, then stop.
--skip-rebuild	Skip the node rebuild: run lo provision + verify only. Use when the nodes are already in the fresh-install state.
--force	Global flag: skip the destructive-consent prompt.

Design: doctor advises, consent lives here, rebuild enforces

Three responsibilities, three owners:

• provider::doctor advises. It is read-only and never blocks: it exists so the operator sees the infrastructure state before deciding.
• lo recover owns consent. The destructive prompt lives in the command, not in the provider hooks. provider::rebuild deliberately does not prompt: a library primitive shouldn't; the operator-facing command does.
• provider::rebuild enforces. Its atomic preflight is the hard safety gate: it resolves and validates every node and refuses to reimage anything unless all of them check out (a name collision or a partial descriptor can never reset the wrong machines, or only some of them).

--dry-run is genuinely safe

--dry-run exports CLOUD_DRY_RUN=1, which flows into provider::rebuild's dry-run branches: it runs the read-only preflight, prints the exact per-node reimage / rescue+reset plan (never the credentials), and reimages nothing. It skips the readiness barrier because no node changed state. It then reports that lo provision would follow and stops without provisioning. Use it to review exactly what a recovery would do before committing.

Data is a separate step

lo recover restores the cluster, not application data. After it reports the nodes Ready, restore etcd/database/PV backups per Backups. A mid-rebuild failure can leave the cluster partially reset. It stops loudly and is re-runnable (the nodes are still mid-reset, so recovery simply resumes).