feat(system api): list instances by domains (#6806)

Allow to list instances by their domains on the system API.

closes #6785

internal/api/grpc/instance/converter.go

@@ -63,6 +63,8 @@ func InstanceQueryToModel(searchQuery *instance_pb.Query) (query.SearchQuery, er
 	switch q := searchQuery.Query.(type) {
 	case *instance_pb.Query_IdQuery:
 		return query.NewInstanceIDsListSearchQuery(q.IdQuery.Ids...)
+	case *instance_pb.Query_DomainQuery:
+		return query.NewInstanceDomainsListSearchQuery(q.DomainQuery.Domains...)
 	default:
 		return nil, errors.ThrowInvalidArgument(nil, "INST-3m0se", "List.Query.Invalid")
 	}

internal/api/grpc/system/instance_integration_test.go

@@ -0,0 +1,109 @@
+//go:build integration
+
+package system_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/zitadel/zitadel/pkg/grpc/instance"
+	"github.com/zitadel/zitadel/pkg/grpc/object"
+	system_pb "github.com/zitadel/zitadel/pkg/grpc/system"
+)
+
+func TestServer_ListInstances(t *testing.T) {
+	domain, instanceID, _ := Tester.UseIsolatedInstance(CTX, SystemCTX)
+
+	tests := []struct {
+		name    string
+		req     *system_pb.ListInstancesRequest
+		want    []*instance.Instance
+		wantErr bool
+	}{
+		{
+			name: "empty query error",
+			req: &system_pb.ListInstancesRequest{
+				Queries: []*instance.Query{{}},
+			},
+			wantErr: true,
+		},
+		{
+			name: "non-existing id",
+			req: &system_pb.ListInstancesRequest{
+				Queries: []*instance.Query{{
+					Query: &instance.Query_IdQuery{
+						IdQuery: &instance.IdsQuery{
+							Ids: []string{"foo"},
+						},
+					},
+				}},
+			},
+			want: []*instance.Instance{},
+		},
+		{
+			name: "get 1 by id",
+			req: &system_pb.ListInstancesRequest{
+				Query: &object.ListQuery{
+					Limit: 1,
+				},
+				Queries: []*instance.Query{{
+					Query: &instance.Query_IdQuery{
+						IdQuery: &instance.IdsQuery{
+							Ids: []string{instanceID},
+						},
+					},
+				}},
+			},
+			want: []*instance.Instance{{
+				Id: instanceID,
+			}},
+		},
+		{
+			name: "non-existing domain",
+			req: &system_pb.ListInstancesRequest{
+				Queries: []*instance.Query{{
+					Query: &instance.Query_DomainQuery{
+						DomainQuery: &instance.DomainsQuery{
+							Domains: []string{"foo"},
+						},
+					},
+				}},
+			},
+			want: []*instance.Instance{},
+		},
+		{
+			name: "get 1 by domain",
+			req: &system_pb.ListInstancesRequest{
+				Query: &object.ListQuery{
+					Limit: 1,
+				},
+				Queries: []*instance.Query{{
+					Query: &instance.Query_DomainQuery{
+						DomainQuery: &instance.DomainsQuery{
+							Domains: []string{domain},
+						},
+					},
+				}},
+			},
+			want: []*instance.Instance{{
+				Id: instanceID,
+			}},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resp, err := Tester.Client.System.ListInstances(SystemCTX, tt.req)
+			if tt.wantErr {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+			got := resp.GetResult()
+			assert.Len(t, got, len(tt.want))
+			for i := 0; i < len(tt.want); i++ {
+				assert.Equalf(t, tt.want[i].GetId(), got[i].GetId(), "instance[%d] id", i)
+			}
+		})
+	}
+}