feat: Add fdb metadata version read in health check

errors/errors.go

@@ -80,6 +80,12 @@ func Aborted(format string, args ...any) error {
 		format, args...)
 }
 
+// Unavailable constructs service unavailable error (HTTP: 503)
+func Unavailable(format string, args ...any) error {
+	return api.Errorf(api.Code_UNAVAILABLE,
+		format, args...)
+}
+
 // Unknown constructs internal server error (HTTP: 500).
 func Unknown(format string, args ...any) error {
 	return api.Errorf(api.Code_UNKNOWN,

server/services/v1/health.go

@@ -22,6 +22,9 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	api "github.com/tigrisdata/tigris/api/server/v1"
+	"github.com/tigrisdata/tigris/errors"
+	"github.com/tigrisdata/tigris/server/metadata"
+	"github.com/tigrisdata/tigris/server/transaction"
 	"google.golang.org/grpc"
 )
 
@@ -31,13 +34,25 @@ const (
 
 type healthService struct {
 	api.UnimplementedHealthAPIServer
+
+	versionH *metadata.VersionHandler
+	txMgr    *transaction.Manager
 }
 
-func newHealthService() *healthService {
-	return &healthService{}
+func newHealthService(txMgr *transaction.Manager) *healthService {
+	return &healthService{
+		versionH: &metadata.VersionHandler{},
+		txMgr:    txMgr,
+	}
 }
 
-func (h *healthService) Health(_ context.Context, _ *api.HealthCheckInput) (*api.HealthCheckResponse, error) {
+func (h *healthService) Health(ctx context.Context, _ *api.HealthCheckInput) (*api.HealthCheckResponse, error) {
+	_, err := h.versionH.ReadInOwnTxn(ctx, h.txMgr, false)
+
+	if err != nil {
+		return nil, errors.Unavailable("Could not read metadata version")
+	}
+
 	return &api.HealthCheckResponse{
 		Response: "OK",
 	}, nil

server/services/v1/service.go

@@ -40,7 +40,7 @@ type Service interface {
 func GetRegisteredServices(kvStore kv.KeyValueStore, searchStore search.Store, tenantMgr *metadata.TenantManager, txMgr *transaction.Manager) []Service {
 	var v1Services []Service
 	v1Services = append(v1Services, newApiService(kvStore, searchStore, tenantMgr, txMgr))
-	v1Services = append(v1Services, newHealthService())
+	v1Services = append(v1Services, newHealthService(txMgr))
 
 	userstore := metadata.NewUserStore(&metadata.DefaultMDNameRegistry{})
 	authProvider := getAuthProvider(userstore, txMgr)