[mqtt] Implements mqtt publish tooling

vendor/github.com/docker/go-connections/sockets/inmem_socket.go

@@ -0,0 +1,81 @@
+package sockets
+
+import (
+	"errors"
+	"net"
+	"sync"
+)
+
+var errClosed = errors.New("use of closed network connection")
+
+// InmemSocket implements net.Listener using in-memory only connections.
+type InmemSocket struct {
+	chConn  chan net.Conn
+	chClose chan struct{}
+	addr    string
+	mu      sync.Mutex
+}
+
+// dummyAddr is used to satisfy net.Addr for the in-mem socket
+// it is just stored as a string and returns the string for all calls
+type dummyAddr string
+
+// 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 NewInmemSocket(addr string, bufSize int) *InmemSocket {
+	return &InmemSocket{
+		chConn:  make(chan net.Conn, bufSize),
+		chClose: make(chan struct{}),
+		addr:    addr,
+	}
+}
+
+// Addr returns the socket's addr string to satisfy net.Listener
+func (s *InmemSocket) Addr() net.Addr {
+	return dummyAddr(s.addr)
+}
+
+// Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.
+func (s *InmemSocket) Accept() (net.Conn, error) {
+	select {
+	case conn := <-s.chConn:
+		return conn, nil
+	case <-s.chClose:
+		return nil, errClosed
+	}
+}
+
+// Close closes the listener. It will be unavailable for use once closed.
+func (s *InmemSocket) Close() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	select {
+	case <-s.chClose:
+	default:
+		close(s.chClose)
+	}
+	return nil
+}
+
+// Dial is used to establish a connection with the in-mem server
+func (s *InmemSocket) Dial(network, addr string) (net.Conn, error) {
+	srvConn, clientConn := net.Pipe()
+	select {
+	case s.chConn <- srvConn:
+	case <-s.chClose:
+		return nil, errClosed
+	}
+
+	return clientConn, nil
+}
+
+// Network returns the addr string, satisfies net.Addr
+func (a dummyAddr) Network() string {
+	return string(a)
+}
+
+// String returns the string form
+func (a dummyAddr) String() string {
+	return string(a)
+}

vendor/github.com/docker/go-connections/sockets/proxy.go

@@ -0,0 +1,51 @@
+package sockets
+
+import (
+	"net"
+	"net/url"
+	"os"
+	"strings"
+
+	"golang.org/x/net/proxy"
+)
+
+// 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 GetProxyEnv(key string) string {
+	proxyValue := os.Getenv(strings.ToUpper(key))
+	if proxyValue == "" {
+		return os.Getenv(strings.ToLower(key))
+	}
+	return proxyValue
+}
+
+// DialerFromEnvironment takes in a "direct" *net.Dialer and returns a
+// proxy.Dialer which will route the connections through the proxy using the
+// given dialer.
+func DialerFromEnvironment(direct *net.Dialer) (proxy.Dialer, error) {
+	allProxy := GetProxyEnv("all_proxy")
+	if len(allProxy) == 0 {
+		return direct, nil
+	}
+
+	proxyURL, err := url.Parse(allProxy)
+	if err != nil {
+		return direct, err
+	}
+
+	proxyFromURL, err := proxy.FromURL(proxyURL, direct)
+	if err != nil {
+		return direct, err
+	}
+
+	noProxy := GetProxyEnv("no_proxy")
+	if len(noProxy) == 0 {
+		return proxyFromURL, nil
+	}
+
+	perHost := proxy.NewPerHost(proxyFromURL, direct)
+	perHost.AddFromString(noProxy)
+
+	return perHost, nil
+}

vendor/github.com/docker/go-connections/sockets/sockets.go

@@ -0,0 +1,38 @@
+// Package sockets provides helper functions to create and configure Unix or TCP sockets.
+package sockets
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"time"
+)
+
+// Why 32? See https://github.com/docker/docker/pull/8035.
+const defaultTimeout = 32 * time.Second
+
+// ErrProtocolNotAvailable is returned when a given transport protocol is not provided by the operating system.
+var ErrProtocolNotAvailable = errors.New("protocol not available")
+
+// ConfigureTransport configures the specified 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.
+func ConfigureTransport(tr *http.Transport, proto, addr string) error {
+	switch proto {
+	case "unix":
+		return configureUnixTransport(tr, proto, addr)
+	case "npipe":
+		return configureNpipeTransport(tr, proto, addr)
+	default:
+		tr.Proxy = http.ProxyFromEnvironment
+		dialer, err := DialerFromEnvironment(&net.Dialer{
+			Timeout: defaultTimeout,
+		})
+		if err != nil {
+			return err
+		}
+		tr.Dial = dialer.Dial
+	}
+	return nil
+}

vendor/github.com/docker/go-connections/sockets/sockets_unix.go

@@ -0,0 +1,35 @@
+// +build !windows
+
+package sockets
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"syscall"
+	"time"
+)
+
+const maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
+
+func configureUnixTransport(tr *http.Transport, proto, addr string) error {
+	if len(addr) > maxUnixSocketPathSize {
+		return fmt.Errorf("Unix socket path %q is too long", addr)
+	}
+	// No need for compression in local communications.
+	tr.DisableCompression = true
+	tr.Dial = func(_, _ string) (net.Conn, error) {
+		return net.DialTimeout(proto, addr, defaultTimeout)
+	}
+	return nil
+}
+
+func configureNpipeTransport(tr *http.Transport, proto, addr string) error {
+	return ErrProtocolNotAvailable
+}
+
+// DialPipe connects to a Windows named pipe.
+// This is not supported on other OSes.
+func DialPipe(_ string, _ time.Duration) (net.Conn, error) {
+	return nil, syscall.EAFNOSUPPORT
+}

vendor/github.com/docker/go-connections/sockets/sockets_windows.go

@@ -0,0 +1,27 @@
+package sockets
+
+import (
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/Microsoft/go-winio"
+)
+
+func configureUnixTransport(tr *http.Transport, proto, addr string) error {
+	return ErrProtocolNotAvailable
+}
+
+func configureNpipeTransport(tr *http.Transport, proto, addr string) error {
+	// No need for compression in local communications.
+	tr.DisableCompression = true
+	tr.Dial = func(_, _ string) (net.Conn, error) {
+		return DialPipe(addr, defaultTimeout)
+	}
+	return nil
+}
+
+// DialPipe connects to a Windows named pipe.
+func DialPipe(addr string, timeout time.Duration) (net.Conn, error) {
+	return winio.DialPipe(addr, &timeout)
+}

vendor/github.com/docker/go-connections/sockets/tcp_socket.go

@@ -0,0 +1,22 @@
+// Package sockets provides helper functions to create and configure Unix or TCP sockets.
+package sockets
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+// 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 NewTCPSocket(addr string, tlsConfig *tls.Config) (net.Listener, error) {
+	l, err := net.Listen("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+	if tlsConfig != nil {
+		tlsConfig.NextProtos = []string{"http/1.1"}
+		l = tls.NewListener(l, tlsConfig)
+	}
+	return l, nil
+}

vendor/github.com/docker/go-connections/sockets/unix_socket.go

@@ -0,0 +1,32 @@
+// +build !windows
+
+package sockets
+
+import (
+	"net"
+	"os"
+	"syscall"
+)
+
+// NewUnixSocket creates a unix socket with the specified path and group.
+func NewUnixSocket(path string, gid int) (net.Listener, error) {
+	if err := syscall.Unlink(path); err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	mask := syscall.Umask(0777)
+	defer syscall.Umask(mask)
+
+	l, err := net.Listen("unix", path)
+	if err != nil {
+		return nil, err
+	}
+	if err := os.Chown(path, 0, gid); err != nil {
+		l.Close()
+		return nil, err
+	}
+	if err := os.Chmod(path, 0660); err != nil {
+		l.Close()
+		return nil, err
+	}
+	return l, nil
+}