domainturva

Self-hosted uptime monitor in Go. Single static binary, FreeBSD-first.

Watches HTTP(S) endpoints, TLS certificate expiry, and domain registration expiry, and sends alerts via Slack or SMTP when something goes sideways.

Install

Build from source

git clone https://github.com/juusomikkonen/domainturva
cd domainturva
make build-freebsd          # produces bin/domainturva-freebsd-amd64

make build produces a native binary for local testing.

Cross-compile

GOOS=freebsd GOARCH=amd64 CGO_ENABLED=0 go build -trimpath \
    -ldflags="-s -w -X main.version=$(git describe --tags --always)" \
    -o bin/domainturva-freebsd-amd64 ./cmd/domainturva

The binary is fully static (no CGO) and portable across FreeBSD installs of the same arch.

Configure

Copy config.example.yaml to your install path (e.g. /usr/local/etc/domainturva/config.yaml) and edit it. Secrets come from env vars referenced as ${VAR_NAME} — the process must have those set, or startup fails fast.

Validate the config any time:

domainturva validate --config /usr/local/etc/domainturva/config.yaml

Run on FreeBSD (rc.d)

# Place the binary
sudo install -m 0755 bin/domainturva-freebsd-amd64 /usr/local/bin/domainturva

# Service user + dirs
sudo pw useradd domainturva -d /nonexistent -s /usr/sbin/nologin
sudo install -d -o domainturva -g domainturva /var/db/domainturva
sudo install -d -o root -g wheel -m 0755 /usr/local/etc/domainturva
sudo install -m 0640 -o root -g domainturva config.example.yaml \
    /usr/local/etc/domainturva/config.yaml

# Secrets file
sudo tee /usr/local/etc/domainturva/env >/dev/null <<'EOF'
SLACK_WEBHOOK_URL=https://hooks.slack.com/services/XXX
SMTP_USER=alerts@example.com
SMTP_PASS=...
EOF
sudo chmod 0640 /usr/local/etc/domainturva/env
sudo chown root:domainturva /usr/local/etc/domainturva/env

# rc.d script
sudo install -m 0755 contrib/domainturva.in /usr/local/etc/rc.d/domainturva

# Enable + start
sudo sysrc domainturva_enable="YES"
sudo service domainturva start

Logs land in /var/log/domainturva.log (JSON). tail -f it.

Subcommands

domainturva run         # default: start the monitor
domainturva check NAME  # one-shot check of a single configured site
domainturva validate    # validate config, exit 0/1
domainturva version     # version + build info

Common flags:

--config <path>     default: ./config.yaml
--log-format json|text   default: json
--log-level debug|info|warn|error   default: info

What it alerts on

Alert type	Trigger
down	Site fails N+1 consecutive checks (retries).
recovered	Site goes up after being down. Includes downtime.
ssl_expiring	Cert crosses one of ssl_warn_days. Renewals re-arm.
ssl_untrusted	Cert is self-signed or chain doesn't validate.
domain_expiring	Registration crosses one of domain_warn_days.
degraded_monitoring	Domain lookups (RDAP+WHOIS) failing for >3 days.

The first observed state for a brand-new site is treated as the baseline; no alert fires until the next transition. This avoids spurious pages on monitor restart.

Healthcheck endpoint

Opt-in; set healthcheck.listen in the config to bind a small HTTP server.

GET /healthz

• 200 OK with a JSON body when at least one HTTP check has completed within 2× the longest configured site interval (or within the same window after startup — startup grace).
• 503 Service Unavailable when the most recent check is older than that.

Example response:

{
  "status": "ok",
  "version": "v0.1.0",
  "uptime_sec": 1234,
  "sites": 4,
  "latest_check_at": "2026-05-08T12:00:00Z",
  "stale_after": "1m0s",
  "stale": false
}

Bind to 127.0.0.1 unless something outside the box needs to reach it.

Supported notifiers

• slack — incoming webhook
• smtp — STARTTLS

To add another: implement notifier.Notifier in internal/notifier/, wire it into buildNotifiers in cmd/domainturva/main.go, and add validation for its config in internal/config.

Development

make test           # unit + integration with -race
make lint
make run            # native build, runs against ./config.yaml

The internal/storage.Memory fake makes it easy to write tests against the alerting and scheduler packages without spinning up SQLite.