vps/runbooks/adguard-home-health.md

# AdGuard Home health — dns.windy.lan

## Purpose

Read-only health check of the AdGuard Home LAN DNS service.

## Scope

- Applicable: [dns.windy.lan](../hosts/dns.windy.lan.md) (`192.168.66.36`).
- Read-only: does not expose query-log contents or secrets; does not change configuration.

This runbook is read-only.  It does not expose query-log contents or secrets.

Routine checks run through Ansible on demand:

```bash
cd ansible
ansible-playbook playbooks/health-report.yml --limit adguardhome
```

The same sanitized profile is installed as a daily server-local timer
(`vps-healthcheck.timer`, output at `/var/lib/vps-health/latest.json`) via
`playbooks/healthchecks.yml`; the manual checks below are for focused diagnosis.

## Verify service and configuration

```bash
ssh -4 -o BatchMode=yes windy@192.168.66.36
sudo docker ps --filter name=^/adguardhome$
sudo docker exec adguardhome /opt/adguardhome/AdGuardHome --check-config \
  -c /opt/adguardhome/conf/AdGuardHome.yaml
sudo ss -lntup | grep -E '(:53|:80)'
```

Expected: DNS listens on TCP/UDP 53, and the HTTP UI listens only on
`192.168.66.36:80`.

## Verify DNS and storage

```bash
dig +time=5 +tries=1 @192.168.66.36 example.com A +noall +comments +answer
dig +time=5 +tries=1 @192.168.66.36 example.com AAAA +noall +comments +answer
dig +time=5 +tries=1 @192.168.66.36 hass.windy.lan A +noall +comments +answer
sudo docker logs --since 30m adguardhome 2>&1 | grep -Ei '\[(error|warn|fatal)\]|level=(error|warn|fatal)' || true
df -h /opt/adguardhome/work
```

The host intentionally accepts DNS from LAN55 and LAN66.  Do not infer a
broken DNS policy merely because `allowed_clients` is empty.

## Verify management UI boundary

From LAN66, the UI should return a login redirect:

```bash
curl -sS -o /dev/null -w '%{http_code}\n' http://192.168.66.36/
```

From a LAN55 source, TCP/80 should time out or be refused by the dedicated
`agh-ui-access.service` nftables rule.  Do not alter this rule to restrict
port 53 without an explicit network-access review.

## DNSSEC and PTR caveats

DNSSEC is currently disabled.  Before enabling it, select upstreams that pass
a known-bad-signature test; an enabled DO bit alone is not validation.

Private PTR forwarding is intentionally absent because the EdgeRouter does
not currently answer private PTR requests.

## Safety

- Read-only: never change the DNS policy or the `agh-ui-access.service` nftables rule during this check.
- Do not infer a broken DNS policy from an empty `allowed_clients`.
- If live state conflicts with an expected value, `STOP` and report.