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Probes

Probes run checks and report results back to the Wacht server. For meaningful distributed monitoring, run at least three probes.

Static Probes​

Static probes are configured in server.yaml:

probes:
  - id: probe-1
    secret: replace-with-a-strong-secret-1
  - id: probe-2
    secret: replace-with-a-strong-secret-2
  - id: probe-3
    secret: replace-with-a-strong-secret-3

Each probe process needs a matching config:

secret: replace-with-a-strong-secret-1
server: http://server:8080
probe_id: probe-1
heartbeat_interval: 30s

Static provisioning is useful for Docker Compose and simple self-host setups.

Dashboard-Created Probes​

Admins can create probe credentials from the dashboard.

The server returns the raw secret once. After that, only a hash is stored, so copy the generated config before leaving the page.

Example generated config:

server: https://wacht.example.com
probe_id: probe-api-1
secret: generated-secret
heartbeat_interval: 30s

Use the public web origin as server when the web container or reverse proxy forwards /api to the Wacht server.

Running A Probe Elsewhere​

A remote probe only needs network access to the Wacht server URL and its own config file. Use the same image tag as the server.

docker run --rm \
  -v "$PWD/config/probe-remote.yaml:/etc/wacht/probe.yaml:ro" \
  ghcr.io/tmater/wacht-probe:0.1 --config=/etc/wacht/probe.yaml

For production, run probes with a process manager or container restart policy.

Private Target Policy​

The server and each probe have independent allow_private_targets settings.

  • The server validates check definitions before saving them.
  • The probe validates destinations again before it dials.

Private monitoring only works when both sides allow private targets.

Current Limitations​

  • Dashboard-created probe credentials cannot be revoked or rotated from the UI yet.
  • Static probe secrets can be rotated by changing server.yaml, changing the matching probe config, and restarting the affected services.
  • All active probes receive the active check set. Per-probe assignment rules are not supported yet.