Disable records instead of deleting them

A disabled record stays in Jarl with its ID, TTL and comment but is
left out of the zone; the zone file lists it as a comment. Web UI
toggle, jarl record disable|enable, record.disable|enable operations
and API endpoints. Database schema 5.

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

internal/validate/records.go

@@ -103,6 +103,31 @@ func (c *checker) zoneLimit(z *model.Zone, name string, def int) int {
 	return n
 }
 
+// checkDisabledRecords warns about disabled records that couldn't be
+// enabled again as the zone is now: the CNAME rules are the usual way a
+// name changes while one of its records is disabled.
+func (c *checker) checkDisabledRecords(z *model.Zone) {
+	served := map[string]map[string]bool{}
+	for _, r := range c.zoneRecords[z.ID] {
+		if served[r.Name] == nil {
+			served[r.Name] = map[string]bool{}
+		}
+		served[r.Name][r.Type] = true
+	}
+	for _, r := range c.allRecords[z.ID] {
+		if !r.Disabled {
+			continue
+		}
+		types := served[r.Name]
+		switch {
+		case r.Type != "CNAME" && types["CNAME"]:
+			c.recProblem(z, r, Warning, "disabled_conflict", "the disabled record %s %s %s can't be enabled again while %s has a CNAME (a CNAME must be the only record at its name)", disp(r.Name), r.Type, r.Data, disp(r.Name))
+		case r.Type == "CNAME" && len(types) > 0:
+			c.recProblem(z, r, Warning, "disabled_conflict", "the disabled CNAME %s → %s can't be enabled again while %s has other records (a CNAME must be the only record at its name)", disp(r.Name), r.Data, disp(r.Name))
+		}
+	}
+}
+
 func (c *checker) checkZoneRecords(z *model.Zone) {
 	ix := &zoneIndex{
 		z:      z,

internal/validate/validate.go

@@ -115,13 +115,14 @@ type checker struct {
 	opts     Options
 	problems []Problem
 	// indexes
-	zoneRecords map[int64][]*model.Record
+	zoneRecords map[int64][]*model.Record // served records (not disabled)
+	allRecords  map[int64][]*model.Record
 	keyNames    map[string]bool
 }
 
 // State validates the complete state.
 func State(s *model.State, opts Options) []Problem {
-	c := &checker{s: s, opts: opts, zoneRecords: s.RecordsByZone(), keyNames: map[string]bool{}}
+	c := &checker{s: s, opts: opts, zoneRecords: s.ServedRecordsByZone(), allRecords: s.RecordsByZone(), keyNames: map[string]bool{}}
 	for _, k := range s.Keys {
 		c.keyNames[k.Name] = true
 	}

internal/validate/zones.go

@@ -105,8 +105,8 @@ func (c *checker) checkZones() {
 				}
 			}
 		}
-		if !z.HasRecords() && len(c.zoneRecords[z.ID]) > 0 {
-			c.zoneProblem(z, Error, "zone_records_unmanaged", "%s zones can't have records managed by Jarl (they get their data from elsewhere); delete the %d records or change the type to primary", z.Type, len(c.zoneRecords[z.ID]))
+		if !z.HasRecords() && len(c.allRecords[z.ID]) > 0 {
+			c.zoneProblem(z, Error, "zone_records_unmanaged", "%s zones can't have records managed by Jarl (they get their data from elsewhere); delete the %d records or change the type to primary", z.Type, len(c.allRecords[z.ID]))
 		}
 	}
 }
@@ -188,6 +188,7 @@ func (c *checker) checkPrimary(z *model.Zone) {
 		c.zoneProblem(z, Info, "zone_name_slash", "zone names with '/' (RFC 2317) are supported, but the file name is escaped")
 	}
 	c.checkZoneRecords(z)
+	c.checkDisabledRecords(z)
 }
 
 // humanSeconds formats a duration in seconds as e.g. "1 day" or "12 hours".