fix(dns plugin): refuse ambiguous zones and add --vpc

docs/cli/datumctl-dns.md

@@ -292,6 +292,19 @@ Drop `--dry-run` to apply the changes. Re-running an unchanged file reports `No
 
 Datum manages some records for you — the zone's SOA and apex NS records, and records created by a Gateway. `apply` never prunes or modifies them, and reports what it skipped.
 
+## Private zones that share a domain
+
+Private zones in different VPCs can use the same domain. Every VPC's default zone is `datum.internal`, for example. When more than one zone matches what you typed, the plugin refuses rather than guess, and lists each zone's object name and the VPCs that use it.
+
+Pick one with `--vpc <name>`, which uses the zone that VPC resolves, or pass the zone's object name in place of the domain:
+
+```sh
+datumctl dns record create datum.internal db A 10.0.0.5 --vpc app
+datumctl dns record list managed-3f9c2a
+```
+
+`--vpc` works on every `record` command and on `zone describe`, `delete`, `nameservers`, `import`, and `export`. It applies only to private zones. Suggested next steps name a private zone by its object name, and deleting a private zone asks you to confirm with its object name.
+
 ## Output formats and scripting
 
 Every command accepts `-o`:
@@ -352,6 +365,7 @@ Add `--verbose` to see the underlying cause.
 | DNS is not enabled for the project | Run `datumctl services enable dns.networking.miloapis.com --wait`. |
 | The domain doesn't resolve | Run `datumctl dns zone nameservers <domain> --check`. If delegation is `Incomplete` or `Partial`, fix it at your registrar. |
 | A record is stuck at `Pending` | This is normal right after a write. If it lasts, run `datumctl dns record describe <domain> <name>` for the server's message. |
+| `N zones in this project match "<domain>"` | Several zones share the domain. See [Private zones that share a domain](#private-zones-that-share-a-domain). |
 | `Conflict` | Another record occupies that name. Usually the name isn't inside the zone — check for `www.example.com` where `www` was meant. Otherwise see [DNS record conflict troubleshooting](../troubleshooting/dnsrecordset-downstream-orphan.md). |
 | `Not owner` | Another record set owns that name; `describe` names it. Edit the record through that set, or delete the set first. Records Datum manages, such as a Gateway's, revert if you edit them. |
 

internal/cmd/dns/record/apply.go

@@ -123,7 +123,7 @@ func runApply(cmd *cobra.Command, domain, file string, prune, dryRun bool) error
 		return err
 	}
 
-	zone, err := resolveZone(ctx, c, domain)
+	zone, err := resolveZone(ctx, c, domain, util.VPCFromCmd(cmd))
 	if err != nil {
 		return err
 	}
@@ -171,7 +171,7 @@ func confirmApply(cmd *cobra.Command, zone *dnsv1alpha1.DNSZone, plan *plan, err
 	}
 	ok, err := util.ConfirmYesNo(cmd.InOrStdin(), errOut,
 		fmt.Sprintf("Apply %d %s to %s?",
-			len(plan.changes), pluralize(len(plan.changes), "change"), zone.Spec.DomainName),
+			len(plan.changes), pluralize(len(plan.changes), "change"), util.ZoneLabel(zone)),
 		false)
 	if err != nil {
 		return err

internal/cmd/dns/record/client.go

@@ -30,10 +30,9 @@ const (
 // can inject a fake client without a control plane behind it.
 var clientFactory = util.NewClient
 
-// resolveZone finds the DNSZone serving a domain. Users type the domain name,
-// which is a selectable field; the object name is accepted as a fallback so a
-// name copied out of `kubectl get dnszones` also works.
-func resolveZone(ctx context.Context, c client.Client, domain string) (*dnsv1alpha1.DNSZone, error) {
+// resolveZone resolves what a user typed, a domain or an object name, to one
+// DNSZone.
+func resolveZone(ctx context.Context, c client.Client, domain, vpc string) (*dnsv1alpha1.DNSZone, error) {
 	name := normalizeDomain(domain)
 	if name == "" {
 		return nil, util.UsageErrorf("a zone domain is required").
@@ -48,23 +47,54 @@ func resolveZone(ctx context.Context, c client.Client, domain string) (*dnsv1alp
 		return nil, util.ClassifyError(fmt.Errorf("listing zones: %w", err))
 	}
 
-	if len(list.Items) > 0 {
-		sort.Slice(list.Items, func(i, j int) bool { return list.Items[i].Name < list.Items[j].Name })
-		return &list.Items[0], nil
-	}
-
 	var byName dnsv1alpha1.DNSZone
 	err := c.Get(ctx, types.NamespacedName{Namespace: util.ResourceNamespace, Name: name}, &byName)
 	switch {
 	case err == nil:
-		return &byName, nil
-	case apierrors.IsNotFound(err):
+		if !containsZone(list.Items, byName.Name) {
+			list.Items = append(list.Items, byName)
+		}
+	case !apierrors.IsNotFound(err):
+		return nil, util.ClassifyError(fmt.Errorf("getting zone: %w", err))
+	}
+
+	if len(list.Items) == 0 {
 		return nil, util.NewCLIError(util.ExitNotFound, fmt.Sprintf("zone %q not found", name)).
 			WithFix("run `datumctl dns zone list` to see the zones in this project.").
 			WithCause(err)
-	default:
-		return nil, util.ClassifyError(fmt.Errorf("getting zone: %w", err))
 	}
+	zone, err := util.PickZone(ctx, c, list.Items, name, vpc)
+	if err != nil {
+		return nil, err
+	}
+	sharing := 0
+	for i := range list.Items {
+		if list.Items[i].Spec.DomainName == zone.Spec.DomainName {
+			sharing++
+		}
+	}
+	if zone.Spec.DomainName != name {
+		var same dnsv1alpha1.DNSZoneList
+		if err := c.List(ctx, &same,
+			client.InNamespace(util.ResourceNamespace),
+			client.MatchingFields{fieldDomainName: zone.Spec.DomainName},
+		); err == nil {
+			sharing = len(same.Items)
+		}
+	}
+	if sharing > 1 {
+		util.MarkSharedDomain(zone)
+	}
+	return zone, nil
+}
+
+func containsZone(zones []dnsv1alpha1.DNSZone, name string) bool {
+	for i := range zones {
+		if zones[i].Name == name {
+			return true
+		}
+	}
+	return false
 }
 
 // normalizeDomain folds a domain to the spelling spec.domainName uses: lowercase

internal/cmd/dns/record/create.go

@@ -131,7 +131,7 @@ func runMutate(cmd *cobra.Command, args []string, opts *mutateOptions) error {
 	if err != nil {
 		return err
 	}
-	zone, err := resolveZone(ctx, c, args[0])
+	zone, err := resolveZone(ctx, c, args[0], util.VPCFromCmd(cmd))
 	if err != nil {
 		return err
 	}

internal/cmd/dns/record/delete.go

@@ -84,7 +84,7 @@ func runDelete(cmd *cobra.Command, args []string, opts *deleteOptions) error {
 	if err != nil {
 		return err
 	}
-	zone, err := resolveZone(ctx, c, args[0])
+	zone, err := resolveZone(ctx, c, args[0], util.VPCFromCmd(cmd))
 	if err != nil {
 		return err
 	}
@@ -103,7 +103,7 @@ func runDelete(cmd *cobra.Command, args []string, opts *deleteOptions) error {
 		return err
 	}
 	if set == nil {
-		return notFoundError(t, ownerName, zoneDomain)
+		return notFoundError(t, ownerName, zoneDomain, util.ZoneArg(zone))
 	}
 	// What is being deleted is established before the managed-record guard, so
 	// a name or value that is simply not there says so rather than being told
@@ -114,9 +114,9 @@ func runDelete(cmd *cobra.Command, args []string, opts *deleteOptions) error {
 			return util.NewCLIError(util.ExitNotFound,
 				fmt.Sprintf("%s has no %s value %q", ownerDisplay(ownerName, zoneDomain), t, rdata.Render(t, *target))).
 				WithFix(fmt.Sprintf("list what is there: datumctl dns record list %s --name %s --type %s",
-					zoneDomain, displayName(ownerName), t))
+					util.ZoneArg(zone), displayName(ownerName), t))
 		}
-		return notFoundError(t, ownerName, zoneDomain)
+		return notFoundError(t, ownerName, zoneDomain, util.ZoneArg(zone))
 	}
 
 	if err := guardMutation(errOut, set, zone, t, ownerName, opts.force); err != nil {
@@ -198,8 +198,8 @@ func deletePrompt(doomed []dnsv1alpha1.RecordEntry, t dnsv1alpha1.RRType, ownerN
 	return fmt.Sprintf("Delete all %d %s records for %s?", len(doomed), t, who)
 }
 
-func notFoundError(t dnsv1alpha1.RRType, ownerName, zoneDomain string) error {
+func notFoundError(t dnsv1alpha1.RRType, ownerName, zoneDomain, zoneArg string) error {
 	return util.NewCLIError(util.ExitNotFound,
 		fmt.Sprintf("no %s records for %s", t, ownerDisplay(ownerName, zoneDomain))).
-		WithFix(fmt.Sprintf("list what is there: datumctl dns record list %s", zoneDomain))
+		WithFix(fmt.Sprintf("list what is there: datumctl dns record list %s", zoneArg))
 }

internal/cmd/dns/record/describe.go

@@ -70,7 +70,7 @@ func runDescribe(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	zone, err := resolveZone(ctx, c, args[0])
+	zone, err := resolveZone(ctx, c, args[0], util.VPCFromCmd(cmd))
 	if err != nil {
 		return err
 	}
@@ -96,7 +96,7 @@ func runDescribe(cmd *cobra.Command, args []string) error {
 		}
 	}
 	if len(owning) == 0 {
-		return describeNotFound(ownerName, zoneDomain, rrTypes)
+		return describeNotFound(ownerName, zoneDomain, util.ZoneArg(zone), rrTypes)
 	}
 
 	switch format {
@@ -190,7 +190,7 @@ func managedBy(p provenance, rs *dnsv1alpha1.DNSRecordSet) string {
 }
 
 func printNextSteps(out io.Writer, zone *dnsv1alpha1.DNSZone, ownerName string, owning []dnsv1alpha1.DNSRecordSet) {
-	domain := zone.Spec.DomainName
+	domain := util.ZoneArg(zone)
 	name := displayName(ownerName)
 	t := string(owning[0].Spec.RecordType)
 
@@ -201,11 +201,11 @@ func printNextSteps(out io.Writer, zone *dnsv1alpha1.DNSZone, ownerName string,
 	_, _ = fmt.Fprintf(out, "  See the whole zone:  datumctl dns record list %s\n", domain)
 }
 
-func describeNotFound(ownerName, zoneDomain string, rrTypes []dnsv1alpha1.RRType) error {
+func describeNotFound(ownerName, zoneDomain, zoneArg string, rrTypes []dnsv1alpha1.RRType) error {
 	if len(rrTypes) == 1 {
-		return notFoundError(rrTypes[0], ownerName, zoneDomain)
+		return notFoundError(rrTypes[0], ownerName, zoneDomain, zoneArg)
 	}
 	return util.NewCLIError(util.ExitNotFound,
 		fmt.Sprintf("no records for %s", ownerDisplay(ownerName, zoneDomain))).
-		WithFix(fmt.Sprintf("list what is there: datumctl dns record list %s", zoneDomain))
+		WithFix(fmt.Sprintf("list what is there: datumctl dns record list %s", zoneArg))
 }

internal/cmd/dns/record/list.go

@@ -144,7 +144,7 @@ func runList(cmd *cobra.Command, domain string, opts *listOptions) error {
 	if err != nil {
 		return err
 	}
-	zone, err := resolveZone(ctx, c, domain)
+	zone, err := resolveZone(ctx, c, domain, util.VPCFromCmd(cmd))
 	if err != nil {
 		return err
 	}
@@ -202,7 +202,7 @@ func runList(cmd *cobra.Command, domain string, opts *listOptions) error {
 	}
 
 	if len(rows) == 0 {
-		printEmpty(out, zone.Spec.DomainName, opts, rrTypes, beforeRowFilters > 0)
+		printEmpty(out, zone.Spec.DomainName, util.ZoneArg(zone), opts, rrTypes, beforeRowFilters > 0)
 		return nil
 	}
 
@@ -468,7 +468,7 @@ func printNames(out io.Writer, rows []row) {
 // different situation from a zone with nothing to show and wants the opposite
 // advice: offering to populate a zone that already holds a thousand records
 // reads as though they have been lost.
-func printEmpty(out io.Writer, domain string, opts *listOptions, rrTypes []dnsv1alpha1.RRType, excludedByFilters bool) {
+func printEmpty(out io.Writer, domain, zoneArg string, opts *listOptions, rrTypes []dnsv1alpha1.RRType, excludedByFilters bool) {
 	// The headline reports what was asked; the advice below reports what to do
 	// about it, and the two turn on different questions.
 	if listIsFiltered(opts) {
@@ -479,8 +479,8 @@ func printEmpty(out io.Writer, domain string, opts *listOptions, rrTypes []dnsv1
 
 	if excludedByFilters {
 		_, _ = fmt.Fprintf(out, "\nNext steps:\n")
-		_, _ = fmt.Fprintf(out, "  Show every record:  datumctl dns record list %s\n", domain)
-		_, _ = fmt.Fprintf(out, "  Widen the filter:   datumctl dns record list %s --help\n", domain)
+		_, _ = fmt.Fprintf(out, "  Show every record:  datumctl dns record list %s\n", zoneArg)
+		_, _ = fmt.Fprintf(out, "  Widen the filter:   datumctl dns record list %s --help\n", zoneArg)
 		return
 	}
 
@@ -491,8 +491,8 @@ func printEmpty(out io.Writer, domain string, opts *listOptions, rrTypes []dnsv1
 		}
 	}
 	_, _ = fmt.Fprintf(out, "\nGet started:\n")
-	_, _ = fmt.Fprintf(out, "  Add a record:   datumctl dns record create %s %s\n", domain, example)
-	_, _ = fmt.Fprintf(out, "  Import a zone:  datumctl dns zone import %s --file zone.txt\n", domain)
+	_, _ = fmt.Fprintf(out, "  Add a record:   datumctl dns record create %s %s\n", zoneArg, example)
+	_, _ = fmt.Fprintf(out, "  Import a zone:  datumctl dns zone import %s --file zone.txt\n", zoneArg)
 }
 
 // warnUnfilterable says so when a row filter was given alongside raw-object

internal/cmd/dns/record/record.go

@@ -12,6 +12,8 @@ package record
 
 import (
 	"github.com/spf13/cobra"
+
+	"go.miloapis.com/dns-operator/internal/cmd/dns/util"
 )
 
 // Command builds the `dns record` noun and its verbs.
@@ -50,6 +52,8 @@ so a value pasted out of a provider export needs no translation.`,
 		},
 	}
 
+	util.AddVPCFlag(cmd.PersistentFlags())
+
 	cmd.AddCommand(
 		listCommand(),
 		createCommand(),