package systemd import ( "errors" "net" "strconv" "github.com/dotcloud/docker/pkg/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 }