minio/cmd/lock-rest-server.go

290 lines
7.3 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 (
"bufio"
"context"
"errors"
"net/http"
"sort"
"strconv"
"time"
"github.com/gorilla/mux"
"github.com/minio/minio/pkg/dsync"
)
const (
// Lock maintenance interval.
lockMaintenanceInterval = 1 * time.Minute
// Lock validity duration
lockValidityDuration = 20 * time.Second
)
// 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 l.ll == nil {
l.writeErrorResponse(w, errLockNotInitialized)
return false
}
if err := storageServerRequestValidate(r); err != nil {
l.writeErrorResponse(w, err)
return false
}
return true
}
func getLockArgs(r *http.Request) (args dsync.LockArgs, err error) {
quorum, err := strconv.Atoi(r.URL.Query().Get(lockRESTQuorum))
if err != nil {
return args, err
}
args = dsync.LockArgs{
Owner: r.URL.Query().Get(lockRESTOwner),
UID: r.URL.Query().Get(lockRESTUID),
Source: r.URL.Query().Get(lockRESTSource),
Quorum: quorum,
}
var resources []string
bio := bufio.NewScanner(r.Body)
for bio.Scan() {
resources = append(resources, bio.Text())
}
if err := bio.Err(); err != nil {
return args, err
}
sort.Strings(resources)
args.Resources = resources
return args, nil
}
// HealthHandler returns success if request is authenticated.
func (l *lockRESTServer) HealthHandler(w http.ResponseWriter, r *http.Request) {
l.IsValid(w, r)
}
// RefreshHandler - refresh the current lock
func (l *lockRESTServer) RefreshHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("invalid request"))
return
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
refreshed, err := l.ll.Refresh(r.Context(), args)
if err != nil {
l.writeErrorResponse(w, err)
return
}
if !refreshed {
l.writeErrorResponse(w, errLockNotFound)
return
}
}
// 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
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
success, err := l.ll.Lock(r.Context(), args)
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
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
_, err = l.ll.Unlock(args)
// 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
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
success, err := l.ll.RLock(r.Context(), args)
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
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
// Ignore the RUnlock() "reply" return value because if err == nil, "reply" is always true.
// Consequently, if err != nil, reply is always false
if _, err = l.ll.RUnlock(args); err != nil {
l.writeErrorResponse(w, err)
return
}
}
// ForceUnlockHandler - query expired lock status.
func (l *lockRESTServer) ForceUnlockHandler(w http.ResponseWriter, r *http.Request) {
if !l.IsValid(w, r) {
l.writeErrorResponse(w, errors.New("invalid request"))
return
}
args, err := getLockArgs(r)
if err != nil {
l.writeErrorResponse(w, err)
return
}
if _, err = l.ll.ForceUnlock(r.Context(), args); err != nil {
l.writeErrorResponse(w, err)
return
}
}
// lockMaintenance loops over all locks and discards locks
// that have not been refreshed for some time.
func lockMaintenance(ctx context.Context) {
// Wait until the object API is ready
// no need to start the lock maintenance
// if ObjectAPI is not initialized.
var objAPI ObjectLayer
for {
objAPI = newObjectLayerFn()
if objAPI == nil {
time.Sleep(time.Second)
continue
}
break
}
if _, ok := objAPI.(*erasureServerPools); !ok {
return
}
// Initialize a new ticker with 1 minute between each ticks.
lkTimer := time.NewTimer(lockMaintenanceInterval)
// Stop the timer upon returning.
defer lkTimer.Stop()
for {
// Verifies every minute for locks held more than 2 minutes.
select {
case <-ctx.Done():
return
case <-lkTimer.C:
// Reset the timer for next cycle.
lkTimer.Reset(lockMaintenanceInterval)
globalLockServer.expireOldLocks(lockValidityDuration)
}
}
}
// registerLockRESTHandlers - register lock rest router.
func registerLockRESTHandlers(router *mux.Router) {
lockServer := &lockRESTServer{
ll: newLocker(),
}
subrouter := router.PathPrefix(lockRESTPrefix).Subrouter()
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodHealth).HandlerFunc(httpTraceHdrs(lockServer.HealthHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRefresh).HandlerFunc(httpTraceHdrs(lockServer.RefreshHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodLock).HandlerFunc(httpTraceHdrs(lockServer.LockHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRLock).HandlerFunc(httpTraceHdrs(lockServer.RLockHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodUnlock).HandlerFunc(httpTraceHdrs(lockServer.UnlockHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRUnlock).HandlerFunc(httpTraceHdrs(lockServer.RUnlockHandler))
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodForceUnlock).HandlerFunc(httpTraceAll(lockServer.ForceUnlockHandler))
globalLockServer = lockServer.ll
go lockMaintenance(GlobalContext)
}