dragonfly/pkg/pidfile/pidfile.go

86 lines
2.1 KiB
Go

/*
* Copyright 2020 The Dragonfly Authors
*
* 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 pidfile
import (
"fmt"
"io/ioutil"
"os"
"strconv"
"strings"
"d7y.io/dragonfly/v2/pkg/util/fileutils"
"github.com/pkg/errors"
"github.com/shirou/gopsutil/v3/process"
)
// PIDFile is a file used to store the process ID and cmdline of a running process.
type PIDFile struct {
path string
pid int
cmdline string
}
func IsProcessExistsByPIDFile(path string) (bool, error) {
bytes, err := ioutil.ReadFile(path)
if err != nil {
return false, err
}
content := strings.TrimSpace(string(bytes))
index := strings.LastIndex(content, "@")
if index == -1 {
return false, errors.New("pid file content is invalid")
}
pid, err := strconv.Atoi(content[index+1:])
if err != nil {
return false, err
}
p, err := process.NewProcess(int32(pid))
if err != nil {
return false, err
}
cmdline, _ := p.Cmdline()
return strings.TrimSpace(cmdline+"@"+strconv.Itoa(pid)) == content, nil
}
// New creates a PIDFile using the specified path.
func New(path string) (*PIDFile, error) {
//if ok, _ := IsProcessExistsByPIDFile(path); ok {
// return nil, errors.Errorf("process already exists")
//}
p, err := process.NewProcess(int32(os.Getpid()))
if err != nil {
return nil, err
}
cmdline, _ := p.Cmdline()
if err := ioutil.WriteFile(path, []byte(fmt.Sprintf("%s@%d", cmdline, p.Pid)), 0644); err != nil {
return nil, err
}
return &PIDFile{path: path, pid: int(p.Pid), cmdline: cmdline}, nil
}
// Remove removes the PIDFile.
func (pf *PIDFile) Remove() error {
return fileutils.DeleteFile(pf.path)
}