diff --git a/02-selfhosting/monitoring/netdata-docker-health-alarm-tuning.md b/02-selfhosting/monitoring/netdata-docker-health-alarm-tuning.md index e232ed5..01a9e2f 100644 --- a/02-selfhosting/monitoring/netdata-docker-health-alarm-tuning.md +++ b/02-selfhosting/monitoring/netdata-docker-health-alarm-tuning.md @@ -5,7 +5,7 @@ category: monitoring tags: [netdata, docker, nextcloud, alarms, health, monitoring] status: published created: 2026-03-18 -updated: 2026-03-21 +updated: 2026-03-22 --- # Tuning Netdata Docker Health Alarms to Prevent Update Flapping @@ -55,6 +55,33 @@ component: Docker The `up` delay is the critical addition. Nextcloud AIO's `nextcloud-aio-nextcloud` container checks both PostgreSQL (port 5432) and PHP-FPM (port 9000). PHP-FPM takes ~90 seconds to warm up after a restart, causing 2–3 failing health checks before the container becomes healthy. With `delay: up 3m`, Netdata waits for 3 continuous minutes of unhealthy status before firing — absorbing the ~90 second startup window with margin to spare. A genuinely broken container will still trigger the alert. +## Also: Suppress `docker_container_down` for Normally-Exiting Containers + +Nextcloud AIO runs `borgbackup` (scheduled backups) and `watchtower` (auto-updates) as containers that exit with code 0 after completing their work. The stock `docker_container_down` alarm fires on any exited container, generating false alerts after every nightly cycle. + +Add a second override to the same file using `chart labels` to exclude them: + +```ini +# Suppress docker_container_down for Nextcloud AIO containers that exit normally +# (borgbackup runs on schedule then exits; watchtower does updates then exits) +template: docker_container_down + on: docker.container_running_state + class: Errors + type: Containers +component: Docker + units: status + every: 30s + lookup: average -5m of down +chart labels: container_name=!nextcloud-aio-borgbackup !nextcloud-aio-watchtower * + warn: $this > 0 + delay: up 3m down 5m multiplier 1.5 max 30m + summary: Docker container ${label:container_name} down + info: ${label:container_name} docker container is down + to: sysadmin +``` + +The `chart labels` line uses Netdata's simple pattern syntax — `!` prefix excludes a container, `*` matches everything else. All other exited containers still alert normally. + ## Applying the Config ```bash @@ -75,7 +102,7 @@ In the Netdata UI, navigate to **Alerts → Manage Alerts** and search for `dock ## Notes -- This only overrides the `docker_container_unhealthy` alarm. The `docker_container_down` alarm (for exited containers) is left at its default — it already has a `delay: down 1m` and is disabled by default (`chart labels: container_name=!*`). +- Both `docker_container_unhealthy` and `docker_container_down` are overridden in this config. Any container not explicitly excluded in the `chart labels` filter will still alert normally. - If you want per-container silencing instead of a blanket delay, use the `host labels` or `chart labels` filter to scope the alarm to specific containers. - Config volume path on majorlab: `/var/lib/docker/volumes/netdata_netdataconfig/_data/`