moby--moby/pkg/pidfile/pidfile.go

45 lines
916 B
Go

package pidfile
import (
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"strconv"
)
type PidFile struct {
path string
}
func checkPidFileAlreadyExists(path string) error {
if pidString, err := ioutil.ReadFile(path); err == nil {
if pid, err := strconv.Atoi(string(pidString)); err == nil {
if _, err := os.Stat(filepath.Join("/proc", string(pid))); err == nil {
return fmt.Errorf("pid file found, ensure docker is not running or delete %s", path)
}
}
}
return nil
}
func New(path string) (file *PidFile, err error) {
if err := checkPidFileAlreadyExists(path); err != nil {
return nil, err
}
file = &PidFile{path: path}
err = ioutil.WriteFile(path, []byte(fmt.Sprintf("%d", os.Getpid())), 0644)
return file, err
}
func (file PidFile) Remove() error {
if err := os.Remove(file.path); err != nil {
log.Printf("Error removing %s: %s", file.path, err)
return err
}
return nil
}