Encrypted DNS health, comparing a zone's views, --local everywhere

jarld checks the DoT and DoH listeners every 10 minutes as a client would (page, dashboard, jarl encrypted-dns health, jarl_encrypted_dns_up). The Compare views tab and jarl zone diff show what differs between a zone's views, with Use this version. --local works on unlinked zones. A changed certificates.dir is followed by encrypted DNS's tls statements. Sharing an already shared version replaces other views' overrides.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/api.md

@@ -353,6 +353,7 @@ and `linked_with` (the other views).
 |--------|------|------|
 | POST | `/zones/{zone}/link` | `{"with": ["external"]}` (default: every view with that zone). Names and types that are the same everywhere become shared, the rest stay local |
 | POST | `/zones/{zone}/unlink` | Takes the zone out of its link; its records stay, all local |
+| GET | `/zones/{zone}/compare` | The zone across the views that have it (`?views=a,b`; `?all=1` also the same rows): `views`, `linked`, `same` (count) and `rows` (name, type, `same`, per view `records`, `ids`, `linked`). The zone may be named without a view |
 
 `POST /zones` takes `"link_with": "VIEW"` to create a zone linked with
 that view's zone of the same name.

docs/certificates.md

@@ -193,7 +193,10 @@ jarl option set listen-on 'port 853 tls dot { 10.0.10.5; }' --add
 ```
 
 A certificate named uses can't be deleted or lose its `dns` use until
-named no longer names its files.
+named no longer names its files. If you change `certificates.dir`, jarld
+writes the certificates to the new place when it starts and points the
+`tls` statements encrypted DNS wrote there (a hand-written `tls`
+statement you change yourself).
 
 ## A certificate you renew yourself
 

docs/cli.md

@@ -221,6 +221,7 @@ jarl zone unlink adbraun.lol --view vps
 jarl record add adbraun.lol nas A 10.0.10.20 --view internal --local   # this view only
 jarl record set adbraun.lol www A 10.0.10.5 --view internal --local    # override the shared www A here
 jarl record update 1234 --local | --shared
+jarl zone diff adbraun.lol [--view V --view W] [--all]                 # what differs between the views
 ```
 
 When a zone exists in several views, add `--view NAME` to commands that
@@ -417,6 +418,7 @@ See [exposure.md](exposure.md).
 jarl encrypted-dns                                   # what is set up, what to give clients
 jarl encrypted-dns setup --hostname dns.adbraun.lol --address 10.0.10.5 [--address IPv6] [--doh-port 8443] [--no-doh]
 jarl encrypted-dns check --address 10.0.10.5 --doh-port 443
+jarl encrypted-dns health                            # check the listeners now, as a client would
 jarl encrypted-dns disable
 ```
 

docs/encrypted-dns.md

@@ -113,6 +113,31 @@ Clients check the certificate against the host name, so the name must
 resolve to this server for them: the setup adds it to your private views.
 Open the ports in the server's firewall for your own networks only.
 
+## Health
+
+jarld checks the listeners itself, a minute after it starts and then
+every 10 minutes, the way a client would: it connects to each, checks the
+certificate named serves (for the host name, current, and the one Jarl
+last wrote, so a renewal named hasn't reread shows up) and asks for the
+host name. The Encrypted DNS page shows the result per listener (**Check
+now** checks again), the dashboard a card and the problems, Prometheus
+`jarl_encrypted_dns_up{kind,address,port}`:
+
+```sh
+jarl encrypted-dns health        # check now; exit 1 when a listener doesn't work
+```
+
+What it can say:
+
+| | |
+|--|--|
+| nothing listens on ADDR port P | named couldn't bind the port: look in named's log (ports below 1024 need named to start as root, as the Debian service does) |
+| no answer within 5s | a firewall on the server |
+| a certificate for X, not HOST | named serves another certificate |
+| an older certificate | named hasn't reread the renewed files (`rndc reconfig`) |
+| not from a CA this server trusts (warning) | a staging or test CA: clients reject it unless they trust it |
+| REFUSED (warning) | it works, but this server's own address gets a view that doesn't answer for the host name |
+
 ## What Jarl checks
 
 * A `tls` statement whose files don't exist is an error
@@ -129,3 +154,4 @@ Open the ports in the server's firewall for your own networks only.
 | POST | `/encrypted-dns/check` | `{"addresses", "dot", "doh", "dot_port", "doh_port"}`: `conflicts` (address, port, what) and `free_doh_port` |
 | POST | `/encrypted-dns` | `{"hostname", "certificate", "addresses", "dot", "doh", "dot_port", "doh_port", "views"}`: staged or applied like any change; 409 while the certificate hasn't been obtained |
 | DELETE | `/encrypted-dns` | Turns it off |
+| POST | `/encrypted-dns/health` | Checks the listeners now: `checked`, `probes` (kind, address, port, `ok`, `problem`, `warning`, certificate names, expiry and serial, `trusted`, `rcode`, `ms`). `GET /encrypted-dns` has the last check as `health` |

docs/metrics.md

@@ -132,6 +132,7 @@ same values.
 | `jarl_certificate_expiry_timestamp_seconds{certificate,source}` | When each certificate Jarl manages expires ([certificates.md](certificates.md)). |
 | `jarl_certificate_failing{certificate,source}` | 1 when obtaining (or reading) the certificate failed the last time, or it has expired. |
 | `jarl_certificate_renewal_failures{certificate}` | Failed attempts to obtain a certificate since its last success. |
+| `jarl_encrypted_dns_up{kind,address,port}` | 1 when the DoT or DoH listener answered with the right, current certificate at the last check ([encrypted-dns.md](encrypted-dns.md#health)). |
 
 ### Queries (with `stats.enabled`)
 
@@ -232,6 +233,11 @@ groups:
         expr: jarl_certificate_expiry_timestamp_seconds - time() < 10 * 86400
         annotations:
           summary: "Certificate {{ $labels.certificate }} expires within 10 days"
+      - alert: EncryptedDNSDown
+        expr: jarl_encrypted_dns_up == 0
+        for: 20m
+        annotations:
+          summary: "DNS over {{ $labels.kind }} on {{ $labels.address }} port {{ $labels.port }} isn't working (see the Encrypted DNS page)"
       - alert: BlockingPausedForLong
         expr: jarl_blocking_paused == 1
         for: 24h

docs/views.md

@@ -209,6 +209,23 @@ each view (Jarl lists them). Share the right version afterwards. Unlinking
 keeps every record, all local; a link left with one zone is dissolved, as
 when the other zone is deleted.
 
+**Comparing the views.** The zone's **Compare views** tab, or `jarl zone
+diff adbraun.lol`, lines the views up and shows each name and type that
+differs: a view's own records, or a name one view lacks. **Use this
+version** (`jarl record update ID --shared`) makes one view's version
+every view's. It works for zones that aren't linked too, to see what
+linking them would keep local.
+
+```
+$ jarl zone diff adbraun.lol
+NAME  TYPE  INTERNAL                    EXTERNAL
+nas   A     10.0.10.20 [local, id 812]  203.0.113.20 [local, id 790]
+5 names and types differ, 21 are the same; linked
+```
+
+`--local` also works on a zone that isn't linked (its records are local
+anyway), so scripts don't need to know; `--shared` there is refused.
+
 **Permissions** are checked in every view a change reaches. A token with
 a grant for one view only (`views=internal`) can change that view's local
 records and make overrides, but not a shared record, since that would