pkg/listeners/listeners_unix.go
Aleksa Sarai d61bb3048b pkg: listeners: separate out the listeners package
This code will be used in containerd and is quite useful in general to
people who want a nice way of creating listeners from proto://address
arguments (even supporting socket activation). Separate it out from
docker/ so people can use it much more easily.

Signed-off-by: Aleksa Sarai <asarai@suse.de>
2016-04-02 01:09:29 +11:00

119 lines
3 KiB
Go

// +build !windows
package listeners
import (
"crypto/tls"
"fmt"
"net"
"strconv"
"github.com/Sirupsen/logrus"
"github.com/coreos/go-systemd/activation"
"github.com/docker/go-connections/sockets"
"github.com/docker/libnetwork/portallocator"
)
// Init creates new listeners for the server.
func Init(proto, addr, socketGroup string, tlsConfig *tls.Config) (ls []net.Listener, err error) {
switch proto {
case "fd":
ls, err = listenFD(addr, tlsConfig)
if err != nil {
return nil, err
}
case "tcp":
l, err := initTCPSocket(addr, tlsConfig)
if err != nil {
return nil, err
}
ls = append(ls, l)
case "unix":
l, err := sockets.NewUnixSocket(addr, socketGroup)
if err != nil {
return nil, fmt.Errorf("can't create unix socket %s: %v", addr, err)
}
ls = append(ls, l)
default:
return nil, fmt.Errorf("Invalid protocol format: %q", proto)
}
return
}
// 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, tlsConfig *tls.Config) ([]net.Listener, error) {
var (
err error
listeners []net.Listener
)
// socket activation
if tlsConfig != nil {
listeners, err = activation.TLSListeners(false, tlsConfig)
} else {
listeners, err = activation.Listeners(false)
}
if err != nil {
return nil, err
}
if len(listeners) == 0 {
return nil, fmt.Errorf("No sockets found. Make sure the docker daemon was started by systemd.")
}
// default to all fds just like unix:// and tcp://
if addr == "" || addr == "*" {
return listeners, nil
}
fdNum, err := strconv.Atoi(addr)
if err != nil {
return nil, fmt.Errorf("failed to parse systemd address, should be number: %v", err)
}
fdOffset := fdNum - 3
if len(listeners) < int(fdOffset)+1 {
return nil, fmt.Errorf("Too few socket activated files passed in")
}
if listeners[fdOffset] == nil {
return nil, fmt.Errorf("failed to listen on systemd activated file at fd %d", fdOffset+3)
}
for i, ls := range listeners {
if i == fdOffset || ls == nil {
continue
}
if err := ls.Close(); err != nil {
logrus.Errorf("Failed to close systemd activated file at fd %d: %v", fdOffset+3, err)
}
}
return []net.Listener{listeners[fdOffset]}, nil
}
// allocateDaemonPort ensures that there are no containers
// that try to use any port allocated for the docker server.
func allocateDaemonPort(addr string) error {
host, port, err := net.SplitHostPort(addr)
if err != nil {
return err
}
intPort, err := strconv.Atoi(port)
if err != nil {
return err
}
var hostIPs []net.IP
if parsedIP := net.ParseIP(host); parsedIP != nil {
hostIPs = append(hostIPs, parsedIP)
} else if hostIPs, err = net.LookupIP(host); err != nil {
return fmt.Errorf("failed to lookup %s address in host specification", host)
}
pa := portallocator.Get()
for _, hostIP := range hostIPs {
if _, err := pa.RequestPort(hostIP, "tcp", intPort); err != nil {
return fmt.Errorf("failed to allocate daemon listening port %d (err: %v)", intPort, err)
}
}
return nil
}