minio/cmd/lock-rest-server.go
2019-11-19 17:42:27 -08:00

157 lines
4.6 KiB
Go

/*
* Minio Cloud Storage, (C) 2019 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"errors"
"net/http"
"path"
"time"
"github.com/gorilla/mux"
"github.com/minio/minio/pkg/dsync"
)
const (
// Lock maintenance interval.
lockMaintenanceInterval = 1 * time.Minute
// Lock validity check interval.
lockValidityCheckInterval = 2 * time.Minute
)
// To abstract a node over network.
type lockRESTServer struct {
ll *localLocker
}
func (l *lockRESTServer) writeErrorResponse(w http.ResponseWriter, err error) {
w.WriteHeader(http.StatusForbidden)
w.Write([]byte(err.Error()))
}
// IsValid - To authenticate and verify the time difference.
func (l *lockRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
if err := storageServerRequestValidate(r); err != nil {
l.writeErrorResponse(w, err)
return false
}
return true
}
func getLockArgs(r *http.Request) dsync.LockArgs {
return dsync.LockArgs{
UID: r.URL.Query().Get(lockRESTUID),
Source: r.URL.Query().Get(lockRESTSource),
Resource: r.URL.Query().Get(lockRESTResource),
}
}
// LockHandler - Acquires a lock.
func (l *lockRESTServer) LockHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("Invalid request"))
return
}
success, err := l.ll.Lock(getLockArgs(r))
if err == nil && !success {
err = errLockConflict
}
if err != nil {
l.writeErrorResponse(w, err)
return
}
}
// UnlockHandler - releases the acquired lock.
func (l *lockRESTServer) UnlockHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("Invalid request"))
return
}
_, err := l.ll.Unlock(getLockArgs(r))
// Ignore the Unlock() "reply" return value because if err == nil, "reply" is always true
// Consequently, if err != nil, reply is always false
if err != nil {
l.writeErrorResponse(w, err)
return
}
}
// LockHandler - Acquires an RLock.
func (l *lockRESTServer) RLockHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("Invalid request"))
return
}
success, err := l.ll.RLock(getLockArgs(r))
if err == nil && !success {
err = errLockConflict
}
if err != nil {
l.writeErrorResponse(w, err)
return
}
}
// RUnlockHandler - releases the acquired read lock.
func (l *lockRESTServer) RUnlockHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("Invalid request"))
return
}
// Ignore the RUnlock() "reply" return value because if err == nil, "reply" is always true.
// Consequently, if err != nil, reply is always false
_, err := l.ll.RUnlock(getLockArgs(r))
if err != nil {
l.writeErrorResponse(w, err)
return
}
}
// registerLockRESTHandlers - register lock rest router.
func registerLockRESTHandlers(router *mux.Router, endpointZones EndpointZones) {
queries := restQueries(lockRESTUID, lockRESTSource, lockRESTResource)
for _, ep := range endpointZones {
for _, endpoint := range ep.Endpoints {
if !endpoint.IsLocal {
continue
}
lockServer := &lockRESTServer{
ll: newLocker(endpoint),
}
subrouter := router.PathPrefix(path.Join(lockRESTPrefix, endpoint.Path)).Subrouter()
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodLock).HandlerFunc(httpTraceHdrs(lockServer.LockHandler)).Queries(queries...)
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRLock).HandlerFunc(httpTraceHdrs(lockServer.RLockHandler)).Queries(queries...)
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodUnlock).HandlerFunc(httpTraceHdrs(lockServer.UnlockHandler)).Queries(queries...)
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRUnlock).HandlerFunc(httpTraceHdrs(lockServer.RUnlockHandler)).Queries(queries...)
globalLockServers[endpoint] = lockServer.ll
}
}
// If none of the routes match add default error handler routes
router.NotFoundHandler = http.HandlerFunc(httpTraceAll(errorResponseHandler))
router.MethodNotAllowedHandler = http.HandlerFunc(httpTraceAll(errorResponseHandler))
}