Add an API endpoint to get backend storage layout version for a given zone.

Signed-off-by: Miod Vallat <[email protected]>

Author: miodvallat

.github/actions/spell-check/expect.txt

@@ -1339,6 +1339,7 @@ stickysidebar
 Stillaway
 Stirnimann
 Stolte
+storageversion
 Storbeck
 Storesund
 stou

docs/http-api/swagger/authoritative-api-swagger.yaml

@@ -1,6 +1,6 @@
 swagger: '2.0'
 info:
-  version: "0.0.17"
+  version: "0.0.18"
   title: PowerDNS Authoritative HTTP API
   license:
     name: MIT
@@ -374,6 +374,19 @@ paths:
             type: string
         <<: *commonErrors
 
+  '/servers/{server_id}/zones/{zone_id}/storageversion':
+    get:
+      summary: 'Return the backend storage version used to store the zone data.'
+      description: 'This returns a backend-dependent version information. Currently only supported by the LMDB backend.'
+      tags:
+        - zones
+      responses:
+        '200':
+          description: Storage version number
+          schema:
+              $ref: '#/definitions/StorageVersion'
+        <<: *commonErrors
+
   '/servers/{server_id}/config':
     get:
       summary: 'Returns all ConfigSettings for a single server'
@@ -1611,3 +1624,10 @@ definitions:
         items:
           $ref: '#/definitions/Network'
 
+  StorageVersion:
+    title: StorageVersion
+    description: 'The version number of the backend storage for a zone'
+    properties:
+      storageversion:
+        type: number
+

pdns/ws-auth.cc

@@ -2403,6 +2403,24 @@ static void apiServerZoneRectify(HttpRequest* req, HttpResponse* resp)
   resp->setSuccessResult("Rectified");
 }
 
+static void apiServerZoneStorageVersion(HttpRequest* req, HttpResponse* resp)
+{
+  ZoneData zoneData{req};
+
+  auto version = zoneData.domainInfo.backend->getStorageLayoutVersion();
+  if (version < 0) {
+    throw ApiException("Storage layout version not available");
+  }
+
+  if (req->accept_json) {
+    resp->setJsonBody(Json::object{{"storageversion", version}});
+  }
+  else {
+    resp->headers["Content-Type"] = "text/plain; charset=us-ascii";
+    resp->body = std::to_string(version);
+  }
+}
+
 // Validate the "changetype" field of a Json patch record.
 // Returns true if this is a replace operation, false if this is a delete
 // operation.
@@ -3047,6 +3065,7 @@ void AuthWebServer::webThread()
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>/metadata", apiZoneMetadataPOST, "POST");
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>/notify", apiServerZoneNotify, "PUT");
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>/rectify", apiServerZoneRectify, "PUT");
+      d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>/storageversion", apiServerZoneStorageVersion, "GET");
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>", apiServerZoneDetailGET, "GET");
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>", apiServerZoneDetailPATCH, "PATCH");
       d_ws->registerApiHandler("/api/v1/servers/localhost/zones/<id>", apiServerZoneDetailPUT, "PUT");

regression-tests.api/test_Zones.py

@@ -2711,6 +2711,18 @@ def test_underscore_names(self):
         # check our record has appeared
         self.assertEqual(get_rrset(data, rrset['name'], 'A')['records'], rrset['records'])
 
+    def test_storage_version(self):
+        name = unique_zone_name()
+        self.create_zone(name=name, kind='Native')
+        # Require a json answer to GET
+        self.session.headers['Content-Type'] = 'application/json'
+        r = self.session.get(self.url("/api/v1/servers/localhost/zones/" + name + "/storageversion"))
+        if is_auth_lmdb():
+            self.assertEqual(r.status_code, 200)
+            self.assertGreater(r.json()['storageversion'], 5)
+        else:
+            self.assertEqual(r.status_code, 422)
+
 @unittest.skipIf(not is_auth(), "Not applicable")
 class AuthRootZone(ZonesApiTestCase, AuthZonesHelperMixin):