зеркало из https://github.com/microsoft/docker.git
51 строка
1.2 KiB
Go
51 строка
1.2 KiB
Go
// Package pidfile provides structure and helper functions to create and remove
|
|
// PID file. A PID file is usually a file used to store the process ID of a
|
|
// running process.
|
|
package pidfile
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"os"
|
|
"path/filepath"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
// PIDFile is a file used to store the process ID of a running process.
|
|
type PIDFile struct {
|
|
path string
|
|
}
|
|
|
|
func checkPIDFileAlreadyExists(path string) error {
|
|
if pidByte, err := ioutil.ReadFile(path); err == nil {
|
|
pidString := strings.TrimSpace(string(pidByte))
|
|
if pid, err := strconv.Atoi(pidString); err == nil {
|
|
if _, err := os.Stat(filepath.Join("/proc", strconv.Itoa(pid))); err == nil {
|
|
return fmt.Errorf("pid file found, ensure docker is not running or delete %s", path)
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// New creates a PIDfile using the specified path.
|
|
func New(path string) (*PIDFile, error) {
|
|
if err := checkPIDFileAlreadyExists(path); err != nil {
|
|
return nil, err
|
|
}
|
|
if err := ioutil.WriteFile(path, []byte(fmt.Sprintf("%d", os.Getpid())), 0644); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &PIDFile{path: path}, nil
|
|
}
|
|
|
|
// Remove removes the PIDFile.
|
|
func (file PIDFile) Remove() error {
|
|
if err := os.Remove(file.path); err != nil {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|