minio/cmd/lock-rest-client.go
Harshavardhana 9cdd981ce7
fix: expire locks only on participating lockers (#11335)
additionally also add a new ForceUnlock API, to
allow forcibly unlocking locks if possible.
2021-01-25 10:01:27 -08:00

176 lines
5.3 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 (
"bytes"
"context"
"io"
"net/url"
"strconv"
"github.com/minio/minio/cmd/http"
xhttp "github.com/minio/minio/cmd/http"
"github.com/minio/minio/cmd/rest"
"github.com/minio/minio/pkg/dsync"
)
// lockRESTClient is authenticable lock REST client
type lockRESTClient struct {
restClient *rest.Client
u *url.URL
}
func toLockError(err error) error {
if err == nil {
return nil
}
switch err.Error() {
case errLockConflict.Error():
return errLockConflict
case errLockNotExpired.Error():
return errLockNotExpired
}
return err
}
// String stringer *dsync.NetLocker* interface compatible method.
func (client *lockRESTClient) String() string {
return client.u.String()
}
// Wrapper to restClient.Call to handle network errors, in case of network error the connection is marked disconnected
// permanently. The only way to restore the connection is at the xl-sets layer by xlsets.monitorAndConnectEndpoints()
// after verifying format.json
func (client *lockRESTClient) callWithContext(ctx context.Context, method string, values url.Values, body io.Reader, length int64) (respBody io.ReadCloser, err error) {
if values == nil {
values = make(url.Values)
}
respBody, err = client.restClient.Call(ctx, method, values, body, length)
if err == nil {
return respBody, nil
}
return nil, toLockError(err)
}
// IsOnline - returns whether REST client failed to connect or not.
func (client *lockRESTClient) IsOnline() bool {
return client.restClient.IsOnline()
}
// Not a local locker
func (client *lockRESTClient) IsLocal() bool {
return false
}
// Close - marks the client as closed.
func (client *lockRESTClient) Close() error {
client.restClient.Close()
return nil
}
// restCall makes a call to the lock REST server.
func (client *lockRESTClient) restCall(ctx context.Context, call string, args dsync.LockArgs) (reply bool, err error) {
values := url.Values{}
values.Set(lockRESTUID, args.UID)
values.Set(lockRESTOwner, args.Owner)
values.Set(lockRESTSource, args.Source)
values.Set(lockRESTQuorum, strconv.Itoa(args.Quorum))
var buffer bytes.Buffer
for _, resource := range args.Resources {
buffer.WriteString(resource)
buffer.WriteString("\n")
}
respBody, err := client.callWithContext(ctx, call, values, &buffer, -1)
defer http.DrainBody(respBody)
switch err {
case nil:
return true, nil
case errLockConflict, errLockNotExpired:
return false, nil
default:
return false, err
}
}
// RLock calls read lock REST API.
func (client *lockRESTClient) RLock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
return client.restCall(ctx, lockRESTMethodRLock, args)
}
// Lock calls lock REST API.
func (client *lockRESTClient) Lock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
return client.restCall(ctx, lockRESTMethodLock, args)
}
// RUnlock calls read unlock REST API.
func (client *lockRESTClient) RUnlock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(context.Background(), lockRESTMethodRUnlock, args)
}
// Unlock calls write unlock RPC.
func (client *lockRESTClient) Unlock(args dsync.LockArgs) (reply bool, err error) {
return client.restCall(context.Background(), lockRESTMethodUnlock, args)
}
// Expired calls expired handler to check if lock args have expired.
func (client *lockRESTClient) Expired(ctx context.Context, args dsync.LockArgs) (expired bool, err error) {
return client.restCall(ctx, lockRESTMethodExpired, args)
}
// ForceUnlock calls force unlock handler to forcibly unlock an active lock.
func (client *lockRESTClient) ForceUnlock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
return client.restCall(ctx, lockRESTMethodForceUnlock, args)
}
func newLockAPI(endpoint Endpoint) dsync.NetLocker {
if endpoint.IsLocal {
return globalLockServer
}
return newlockRESTClient(endpoint)
}
// Returns a lock rest client.
func newlockRESTClient(endpoint Endpoint) *lockRESTClient {
serverURL := &url.URL{
Scheme: endpoint.Scheme,
Host: endpoint.Host,
Path: pathJoin(lockRESTPrefix, lockRESTVersion),
}
restClient := rest.NewClient(serverURL, globalInternodeTransport, newAuthToken)
restClient.ExpectTimeouts = true
// Use a separate client to avoid recursive calls.
healthClient := rest.NewClient(serverURL, globalInternodeTransport, newAuthToken)
healthClient.ExpectTimeouts = true
restClient.HealthCheckFn = func() bool {
ctx, cancel := context.WithTimeout(GlobalContext, restClient.HealthCheckTimeout)
defer cancel()
respBody, err := healthClient.Call(ctx, lockRESTMethodHealth, nil, nil, -1)
xhttp.DrainBody(respBody)
return !isNetworkError(err)
}
return &lockRESTClient{u: &url.URL{
Scheme: endpoint.Scheme,
Host: endpoint.Host,
}, restClient: restClient}
}