K8s: Dashboards: Add useful error message for too large (#101590)

pkg/api/apierrors/dashboard.go

@@ -7,9 +7,11 @@ import (
 	"net/http"
 
 	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/services/apiserver"
 	"github.com/grafana/grafana/pkg/services/dashboards"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/pluginstore"
 	"github.com/grafana/grafana/pkg/util"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 )
 
 // ToDashboardErrorResponse returns a different response status according to the dashboard error type
@@ -39,5 +41,9 @@ func ToDashboardErrorResponse(ctx context.Context, pluginStore pluginstore.Store
 		return response.JSON(http.StatusPreconditionFailed, util.DynMap{"status": "plugin-dashboard", "message": message})
 	}
 
+	if apierrors.IsRequestEntityTooLargeError(err) {
+		return response.Error(http.StatusRequestEntityTooLarge, fmt.Sprintf("Dashboard is too large, max is %d MB", apiserver.MaxRequestBodyBytes/1024/1024), err)
+	}
+
 	return response.Error(http.StatusInternalServerError, "Failed to save dashboard", err)
 }

pkg/services/apiserver/service.go

@@ -80,6 +80,8 @@ var (
 	ready      = make(chan struct{})
 )
 
+const MaxRequestBodyBytes = 16 * 1024 * 1024 // 16MB - determined by the size of `mediumtext` on mysql, which is used to save dashboard data
+
 func init() {
 	// we need to add the options to empty v1
 	metav1.AddToGroupVersion(Scheme, schema.GroupVersion{Group: "", Version: "v1"})
@@ -335,7 +337,7 @@ func (s *service) start(ctx context.Context) error {
 	transport := &roundTripperFunc{ready: make(chan struct{})}
 	serverConfig.LoopbackClientConfig.Transport = transport
 	serverConfig.LoopbackClientConfig.TLSClientConfig = clientrest.TLSClientConfig{}
-	serverConfig.MaxRequestBodyBytes = 16 * 1024 * 1024 // 16MB - determined by the size of `mediumtext` on mysql, which is used to save dashboard data
+	serverConfig.MaxRequestBodyBytes = MaxRequestBodyBytes
 
 	var optsregister apistore.StorageOptionsRegister