VTAdmin: Add support for Create Reshard (#16903)

Signed-off-by: Noble Mittal <[email protected]>

go/vt/vtadmin/api.go

@@ -426,6 +426,7 @@ func (api *API) Handler() http.Handler {
 	router.HandleFunc("/workflow/{cluster_id}/{keyspace}/{name}/start", httpAPI.Adapt(vtadminhttp.StartWorkflow)).Name("API.StartWorkflow")
 	router.HandleFunc("/workflow/{cluster_id}/{keyspace}/{name}/stop", httpAPI.Adapt(vtadminhttp.StopWorkflow)).Name("API.StopWorkflow")
 	router.HandleFunc("/workflow/{cluster_id}/movetables", httpAPI.Adapt(vtadminhttp.MoveTablesCreate)).Name("API.MoveTablesCreate").Methods("POST")
+	router.HandleFunc("/workflow/{cluster_id}/reshard", httpAPI.Adapt(vtadminhttp.ReshardCreate)).Name("API.ReshardCreate").Methods("POST")
 
 	experimentalRouter := router.PathPrefix("/experimental").Subrouter()
 	experimentalRouter.HandleFunc("/tablet/{tablet}/debug/vars", httpAPI.Adapt(experimental.TabletDebugVarsPassthrough)).Name("API.TabletDebugVarsPassthrough")
@@ -1888,6 +1889,25 @@ func (api *API) MoveTablesCreate(ctx context.Context, req *vtadminpb.MoveTablesC
 	return c.Vtctld.MoveTablesCreate(ctx, req.Request)
 }
 
+// ReshardCreate is part of the vtadminpb.VTAdminServer interface.
+func (api *API) ReshardCreate(ctx context.Context, req *vtadminpb.ReshardCreateRequest) (*vtctldatapb.WorkflowStatusResponse, error) {
+	span, ctx := trace.NewSpan(ctx, "API.ReshardCreate")
+	defer span.Finish()
+
+	span.Annotate("cluster_id", req.ClusterId)
+
+	if !api.authz.IsAuthorized(ctx, req.ClusterId, rbac.WorkflowResource, rbac.CreateAction) {
+		return nil, fmt.Errorf("%w: cannot create workflow in %s", errors.ErrUnauthorized, req.ClusterId)
+	}
+
+	c, err := api.getClusterForRequest(req.ClusterId)
+	if err != nil {
+		return nil, err
+	}
+
+	return c.Vtctld.ReshardCreate(ctx, req.Request)
+}
+
 // PingTablet is part of the vtadminpb.VTAdminServer interface.
 func (api *API) PingTablet(ctx context.Context, req *vtadminpb.PingTabletRequest) (*vtadminpb.PingTabletResponse, error) {
 	span, ctx := trace.NewSpan(ctx, "API.PingTablet")

go/vt/vtadmin/http/workflows.go

@@ -145,3 +145,27 @@ func MoveTablesCreate(ctx context.Context, r Request, api *API) *JSONResponse {
 
 	return NewJSONResponse(res, err)
 }
+
+// ReshardCreate implements the http wrapper for the VTAdminServer.ReshardCreate
+// method.
+//
+// Its route is /workflow/{cluster_id}/reshard
+func ReshardCreate(ctx context.Context, r Request, api *API) *JSONResponse {
+	vars := r.Vars()
+	decoder := json.NewDecoder(r.Body)
+	defer r.Body.Close()
+
+	var req vtctldatapb.ReshardCreateRequest
+	if err := decoder.Decode(&req); err != nil {
+		return NewJSONResponse(nil, &errors.BadRequest{
+			Err: err,
+		})
+	}
+
+	res, err := api.server.ReshardCreate(ctx, &vtadminpb.ReshardCreateRequest{
+		ClusterId: vars["cluster_id"],
+		Request:   &req,
+	})
+
+	return NewJSONResponse(res, err)
+}

proto/vtadmin.proto

@@ -173,6 +173,8 @@ service VTAdmin {
     rpc RetrySchemaMigration(RetrySchemaMigrationRequest) returns (vtctldata.RetrySchemaMigrationResponse) {};
     // RunHealthCheck runs a healthcheck on the tablet.
     rpc RunHealthCheck(RunHealthCheckRequest) returns (RunHealthCheckResponse) {};
+    // ReshardCreate creates a workflow to reshard a keyspace.
+    rpc ReshardCreate(ReshardCreateRequest) returns (vtctldata.WorkflowStatusResponse) {};
     // SetReadOnly sets the tablet to read-only mode.
     rpc SetReadOnly(SetReadOnlyRequest) returns (SetReadOnlyResponse) {};
     // SetReadWrite sets the tablet to read-write mode.
@@ -917,6 +919,11 @@ message RunHealthCheckResponse {
     Cluster cluster = 2;
 }
 
+message ReshardCreateRequest {
+    string cluster_id = 1;
+    vtctldata.ReshardCreateRequest request = 2;
+}
+
 message SetReadOnlyRequest {
     topodata.TabletAlias alias = 1;
     repeated string cluster_ids = 2;