sockets

Documentation

Overview

Package sockets provides helper functions to create and configure Unix or TCP sockets.

Package sockets provides helper functions to create and configure Unix or TCP sockets.

Package sockets is a simple unix domain socket wrapper.

Usage

For example:

import(
	"fmt"
	"net"
	"os"
	"github.com/docker/go-connections/sockets"
)

func main() {
	l, err := sockets.NewUnixSocketWithOpts("/path/to/sockets",
		sockets.WithChown(0,0),sockets.WithChmod(0660))
	if err != nil {
		panic(err)
	}
	echoStr := "hello"

	go func() {
		for {
			conn, err := l.Accept()
			if err != nil {
				return
			}
			conn.Write([]byte(echoStr))
			conn.Close()
		}
	}()

	conn, err := net.Dial("unix", path)
	if err != nil {
		t.Fatal(err)
	}

	buf := make([]byte, 5)
	if _, err := conn.Read(buf); err != nil {
		panic(err)
	} else if string(buf) != echoStr {
		panic(fmt.Errorf("msg may lost"))
	}
}

Index

• Variables
• func ConfigureTransport(tr *http.Transport, proto, addr string) error
• func DialPipe(_ string, _ time.Duration) (net.Conn, error)
• func DialerFromEnvironment(direct *net.Dialer) (*net.Dialer, error)
• func GetProxyEnv(key string) string
• func NewTCPSocket(addr string, tlsConfig *tls.Config) (net.Listener, error)
• func NewUnixSocket(path string, gid int) (net.Listener, error)
• func NewUnixSocketWithOpts(path string, opts ...SockOption) (net.Listener, error)
• type InmemSocket
  • func NewInmemSocket(addr string, bufSize int) *InmemSocket
  • func (s *InmemSocket) Accept() (net.Conn, error)
  • func (s *InmemSocket) Addr() net.Addr
  • func (s *InmemSocket) Close() error
  • func (s *InmemSocket) Dial(network, addr string) (net.Conn, error)
• type SockOption
  • func WithChmod(mask os.FileMode) SockOption
  • func WithChown(uid, gid int) SockOption

Variables

var ErrProtocolNotAvailable = errors.New("protocol not available")

ErrProtocolNotAvailable is returned when a given transport protocol is not provided by the operating system.

Functions

func ConfigureTransport

func ConfigureTransport(tr *http.Transport, proto, addr string) error

ConfigureTransport configures the specified http.Transport according to the specified proto and addr.

If the proto is unix (using a unix socket to communicate) or npipe the compression is disabled. For other protos, compression is enabled. If you want to manually enable/disable compression, make sure you do it _after_ any subsequent calls to ConfigureTransport is made against the same http.Transport.

func DialPipe

func DialPipe(_ string, _ time.Duration) (net.Conn, error)

DialPipe connects to a Windows named pipe. This is not supported on other OSes.

func DialerFromEnvironment

func DialerFromEnvironment(direct *net.Dialer) (*net.Dialer, error)

DialerFromEnvironment was previously used to configure a net.Dialer to route connections through a SOCKS proxy. DEPRECATED: SOCKS proxies are now supported by configuring only http.Transport.Proxy, and no longer require changing http.Transport.Dial. Therefore, only sockets.ConfigureTransport() needs to be called, and any sockets.DialerFromEnvironment() calls can be dropped.

func GetProxyEnv

func GetProxyEnv(key string) string

GetProxyEnv allows access to the uppercase and the lowercase forms of proxy-related variables. See the Go specification for details on these variables. https://golang.org/pkg/net/http/

func NewTCPSocket

func NewTCPSocket(addr string, tlsConfig *tls.Config) (net.Listener, error)

NewTCPSocket creates a TCP socket listener with the specified address and the specified tls configuration. If TLSConfig is set, will encapsulate the TCP listener inside a TLS one.

func NewUnixSocket

func NewUnixSocket(path string, gid int) (net.Listener, error)

NewUnixSocket creates a unix socket with the specified path and group.

func NewUnixSocketWithOpts

func NewUnixSocketWithOpts(path string, opts ...SockOption) (net.Listener, error)

NewUnixSocketWithOpts creates a unix socket with the specified options. By default, socket permissions are 0000 (i.e.: no access for anyone); pass WithChmod() and WithChown() to set the desired ownership and permissions.

This function temporarily changes the system's "umask" to 0777 to work around a race condition between creating the socket and setting its permissions. While this should only be for a short duration, it may affect other processes that create files/directories during that period.

Types

type InmemSocket

type InmemSocket struct {
	// contains filtered or unexported fields
}

InmemSocket implements net.Listener using in-memory only connections.

func NewInmemSocket

func NewInmemSocket(addr string, bufSize int) *InmemSocket

NewInmemSocket creates an in-memory only net.Listener The addr argument can be any string, but is used to satisfy the `Addr()` part of the net.Listener interface

func (*InmemSocket) Accept

func (s *InmemSocket) Accept() (net.Conn, error)

Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.

func (*InmemSocket) Addr

func (s *InmemSocket) Addr() net.Addr

Addr returns the socket's addr string to satisfy net.Listener

func (*InmemSocket) Close

func (s *InmemSocket) Close() error

Close closes the listener. It will be unavailable for use once closed.

func (*InmemSocket) Dial

func (s *InmemSocket) Dial(network, addr string) (net.Conn, error)

Dial is used to establish a connection with the in-mem server

type SockOption

type SockOption func(string) error

SockOption sets up socket file's creating option

func WithChmod

func WithChmod(mask os.FileMode) SockOption

WithChmod modifies socket file's access mode.

func WithChown

func WithChown(uid, gid int) SockOption

WithChown modifies the socket file's uid and gid