pkg/systemd/listendfd.go
Brandon Philips 8362e7cc10 Move listenfd to utility package
Docker-DCO-1.1-Signed-off-by: Brandon Philips <brandon.philips@coreos.com> (github: philips)
2014-01-27 17:18:09 -08:00

41 lines
970 B
Go

package systemd
import (
"errors"
"fmt"
"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) {
files := activation.Files(false)
if files == nil || len(files) == 0 {
return nil, errors.New("No sockets found")
}
fdNum, _ := strconv.Atoi(addr)
fdOffset := fdNum - 3
if (addr != "*") && (len(files) < int(fdOffset)+1) {
return nil, errors.New("Too few socket activated files passed in")
}
// socket activation
listeners := make([]net.Listener, len(files))
for i, f := range files {
var err error
listeners[i], err = net.FileListener(f)
if err != nil {
return nil, fmt.Errorf("Error setting up FileListener for fd %d: %s", f.Fd(), err.Error())
}
}
if addr == "*" {
return listeners, nil
}
return []net.Listener{listeners[fdOffset]}, nil
}