jarl/docs/operations.md

Running Jarl

Day to day

Task	How
Is everything healthy?	jarl status, or the web UI dashboard: named reachable, adoption, drift, open changesets, configuration problems
What changed and who did it?	jarl history, jarl changeset show ID (with diff), jarl audit
Undo a change	jarl changeset revert ID, review it, then jarl changeset apply NEW_ID (or History → Revert in the UI)
Check the configuration	jarl check: full validation plus named-checkconf -z
Logs	journalctl -u jarl (jarld, including msg=audit lines), journalctl -u named
Restart / reload TLS	systemctl restart jarl / systemctl reload jarl

Restarting jarld doesn't affect DNS: named keeps serving the files it loaded. jarld is only needed to make changes.

Backups

Everything Jarl knows is in its database. The BIND files can be generated from it again at any time.

sudo -u jarl jarld backup /var/backups/jarl/jarl-$(date +%F).db   # consistent copy, safe while jarld runs

For example, as a daily timer or cron job:

# /etc/cron.daily/jarl-backup
#!/bin/sh
set -e
install -d -o jarl -g jarl -m 0700 /var/backups/jarl
sudo -u jarl jarld backup /var/backups/jarl/jarl-$(date +%F).db
find /var/backups/jarl -name 'jarl-*.db' -mtime +30 -delete

Query statistics live in a separate database (/var/lib/jarl/stats.db). It isn't needed to restore DNS, so back it up only if you want to keep the history.

The database contains password and token hashes and the TSIG secrets in the clear, so keep backups private.

Restoring

systemctl stop jarl
install -o jarl -g jarl -m 0600 /var/backups/jarl/jarl-2026-10-01.db /var/lib/jarl/jarl.db
rm -f /var/lib/jarl/jarl.db-wal /var/lib/jarl/jarl.db-shm
systemctl start jarl
jarl resync --dry-run     # what differs between the restored database and the files
jarl resync --force       # write everything and reload named

An older backup can carry lower zone serials than named last served. Your own named doesn't mind, but secondaries and caches ignore a serial that went backwards. If you have secondaries, raise the serials after a restore: jarl zone update ZONE --serial <higher>.

Drift: files changed outside Jarl

Jarl keeps a checksum of every file it writes. If someone edits /etc/bind/jarl/named.conf or a zone file by hand (or a restore puts old files back), jarl status and the dashboard show drift, and changes that would overwrite those files are refused with 409 drift:

error: files managed by Jarl were changed outside Jarl: /var/lib/bind/jarl/internal/adbraun.lol.zone; review them and apply with force to overwrite

Decide which version is right:

• Jarl's (the usual case): jarl resync --force rewrites every file from the database and reloads named. Any single change with --force also overwrites the drifted files.
• The hand edit: put the same change into Jarl (for example jarl zone import ZONE /var/lib/bind/jarl/internal/adbraun.lol.zone for records), then jarl resync --force.

When an apply fails

Jarl checks everything it can before it touches named, so failures are rare. When one happens, nothing is left half-done:

Stage	What you see	State afterwards
validation	422 with problems	Nothing written
named-checkconf / named-checkzone	422 validation_failed with the checker's messages in check, mapped to the zone/option that caused them	Nothing written
rndc reconfig / reload fails, or a zone doesn't load within reload_timeout	502 bind_failed	Previous files restored and named reloaded

A failed change is never recorded as applied. A staged changeset stays open, so you can fix it and apply again, and the failure is in the audit log (jarl audit --outcome failure). named's own log usually explains a load failure: journalctl -u named.

If named isn't running, changes fail at the reload step and are rolled back. Start named, then apply again.

Recovering access

Problem	Fix (on the server)
Forgot the admin password	sudo -u jarl jarld user passwd admin
Locked out by the login rate limit	wait 15 minutes, or systemctl restart jarl (the limiter is in memory)
Lost every admin account	sudo -u jarl jarld user add --admin rescue
Need a token without the web UI	sudo -u jarl jarld user token admin cli

A secondary server

A second name server runs its own named and jarld; its zones are of type secondary and copy the primary's records by zone transfer, so you only ever edit records on the primary. With both named in the CLI configuration (cli.md):

# 1. One TSIG key with the same secret on both servers.
jarl -s ns1 tsig create xfer                     # prints the secret
jarl -s ns2 tsig create xfer --secret 'THE-SECRET'

# 2. On the primary: let the key transfer the zone, and list ns2 as a
#    name server (named sends NOTIFY to the zone's NS records).
jarl -s ns1 option set allow-transfer '{ key xfer; }' --zone adbraun.lol
jarl -s ns1 record add adbraun.lol @ NS ns2.adbraun.lol.

# 3. On the secondary: the zone, copied from the primary with the key.
jarl -s ns2 zone create adbraun.lol --type secondary --primary "192.0.2.53 key xfer"

If ns2 isn't one of the zone's NS records, add also-notify { ADDRESS; }; on the primary so it learns about changes quickly. With views, each view's zones are transferred separately; match the secondary's requests to the right view, for example with match-clients { key xfer; ... };.

Things that both servers need, such as ACLs, can be changed on both at once with a group (jarl -s dns acl update ...): the change is checked on both first and applied only if both accept it.

Taking Jarl out of the picture

The generated files are plain BIND configuration. To stop using Jarl, disable the service. named keeps working with /etc/bind/jarl/ exactly as it is. To go back to the configuration you had before adopting:

cp /etc/bind/named.conf.pre-jarl-<date> /etc/bind/named.conf
rndc reconfig

Monitoring

• GET /healthz (no authentication) reports that jarld is up.
• GET /api/v1/status with a read-only token reports named reachability, drift and configuration problems. It is suitable for a monitoring check:

  jarl --token @/etc/jarl/monitor.token status -o json | jq -e '.engine.drift == [] and .engine.adopted'
  

• The audit log records failed logins as auth.login_failed / auth.login_blocked, and rejected tokens as auth.token_failed.