docker/pkg/systemd/listendfd.go

41 строка
861 B
Go

package systemd
import (
"errors"
"net"
"strconv"
"github.com/coreos/go-systemd/activation"
)
// ListenFD returns the specified socket activated files as a slice of
// net.Listeners or all of the activated files if "*" is given.
func ListenFD(addr string) ([]net.Listener, error) {
// socket activation
listeners, err := activation.Listeners(false)
if err != nil {
return nil, err
}
if listeners == nil || len(listeners) == 0 {
return nil, errors.New("No sockets found")
}
// default to all fds just like unix:// and tcp://
if addr == "" {
addr = "*"
}
fdNum, _ := strconv.Atoi(addr)
fdOffset := fdNum - 3
if (addr != "*") && (len(listeners) < int(fdOffset)+1) {
return nil, errors.New("Too few socket activated files passed in")
}
if addr == "*" {
return listeners, nil
}
return []net.Listener{listeners[fdOffset]}, nil
}