Merge pull request #1208 from weaveworks/1016-host-level-ttys

host-level ttys

common/xfer/pipes.go

@@ -27,7 +27,16 @@ type pipe struct {
 	onClose         func()
 }
 
-// NewPipe makes a new... pipe.
+// NewPipeFromEnds makes a new pipe specifying its ends
+func NewPipeFromEnds(local io.ReadWriter, remote io.ReadWriter) Pipe {
+	return &pipe{
+		port:      local,
+		starboard: remote,
+		quit:      make(chan struct{}),
+	}
+}
+
+// NewPipe makes a new pipe
 func NewPipe() Pipe {
 	r1, w1 := io.Pipe()
 	r2, w2 := io.Pipe()

integration/410_container_control_test.sh

@@ -13,8 +13,6 @@ wait_for_containers $HOST1 60 alpine
 
 assert "docker_on $HOST1 inspect --format='{{.State.Running}}' alpine" "true"
 PROBEID=$(docker_on $HOST1 logs weavescope 2>&1 | grep "probe starting" | sed -n 's/^.*ID \([0-9a-f]*\)$/\1/p')
-HOSTID=$(echo $HOST1 | cut -d"." -f1)
-
 
 # Execute 'echo foo' in a container tty and check its output
 PIPEID=$(curl -s -f -X POST  "http://$HOST1:4040/api/control/$PROBEID/$CID;<container>/docker_exec_container" | jq -r '.pipe' )

integration/420_host_control_test.sh

@@ -0,0 +1,19 @@
+#! /bin/bash
+
+. ./config.sh
+
+start_suite "Test host controls"
+
+weave_on $HOST1 launch
+scope_on $HOST1 launch
+
+sleep 10
+
+PROBEID=$(docker_on $HOST1 logs weavescope 2>&1 | grep "probe starting" | sed -n 's/^.*ID \([0-9a-f]*\)$/\1/p')
+HOSTID=$($SSH $HOST1 hostname)
+
+# Execute 'echo foo' in the host tty and check its output
+PIPEID=$(curl -s -f -X POST  "http://$HOST1:4040/api/control/$PROBEID/$HOSTID;<host>/host_exec" | jq -r '.pipe' )
+assert "(sleep 1 && echo \"PS1=''; echo foo\" && sleep 1) | wscat -b 'ws://$HOST1:4040/api/pipe/$PIPEID' | col -pb | tail -n 1" "foo\n"
+
+scope_end_suite

probe/controls/pipes.go

@@ -2,6 +2,7 @@ package controls
 
 import (
 	"fmt"
+	"io"
 	"math/rand"
 
 	"github.com/weaveworks/scope/common/xfer"
@@ -21,11 +22,10 @@ type pipe struct {
 	client    PipeClient
 }
 
-// NewPipe creats a new pipe and connects it to the app.
-var NewPipe = func(c PipeClient, appID string) (string, xfer.Pipe, error) {
+func newPipe(p xfer.Pipe, c PipeClient, appID string) (string, xfer.Pipe, error) {
 	pipeID := fmt.Sprintf("pipe-%d", rand.Int63())
 	pipe := &pipe{
-		Pipe:   xfer.NewPipe(),
+		Pipe:   p,
 		appID:  appID,
 		id:     pipeID,
 		client: c,
@@ -36,6 +36,16 @@ var NewPipe = func(c PipeClient, appID string) (string, xfer.Pipe, error) {
 	return pipeID, pipe, nil
 }
 
+// NewPipe creates a new pipe and connects it to the app.
+var NewPipe = func(c PipeClient, appID string) (string, xfer.Pipe, error) {
+	return newPipe(xfer.NewPipe(), c, appID)
+}
+
+// NewPipeFromEnds creates a new pipe from its ends and connects it to the app.
+func NewPipeFromEnds(local, remote io.ReadWriter, c PipeClient, appID string) (string, xfer.Pipe, error) {
+	return newPipe(xfer.NewPipeFromEnds(local, remote), c, appID)
+}
+
 func (p *pipe) Close() error {
 	err1 := p.Pipe.Close()
 	err2 := p.client.PipeClose(p.appID, p.id)

probe/docker/controls.go

@@ -10,7 +10,7 @@ import (
 	"github.com/weaveworks/scope/report"
 )
 
-// Control IDs used by the docker intergation.
+// Control IDs used by the docker integration.
 const (
 	StopContainer    = "docker_stop_container"
 	StartContainer   = "docker_start_container"

probe/docker/reporter.go

@@ -102,7 +102,7 @@ func (r *Reporter) containerTopology(localAddrs []net.IP) report.Topology {
 	})
 	result.Controls.AddControl(report.Control{
 		ID:    ExecContainer,
-		Human: "Exec /bin/sh",
+		Human: "Exec shell",
 		Icon:  "fa-terminal",
 	})
 

probe/host/controls.go

@@ -0,0 +1,58 @@
+package host
+
+import (
+	"os/exec"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/kr/pty"
+
+	"github.com/weaveworks/scope/common/xfer"
+	"github.com/weaveworks/scope/probe/controls"
+)
+
+// Control IDs used by the host integration.
+const (
+	ExecHost = "host_exec"
+)
+
+func (r *Reporter) registerControls() {
+	controls.Register(ExecHost, r.execHost)
+}
+
+func (*Reporter) deregisterControls() {
+	controls.Rm(ExecHost)
+}
+
+func (r *Reporter) execHost(req xfer.Request) xfer.Response {
+	cmd := exec.Command(r.hostShellCmd[0], r.hostShellCmd[1:]...)
+	cmd.Env = []string{"TERM=xterm"}
+	ptyPipe, err := pty.Start(cmd)
+	if err != nil {
+		return xfer.ResponseError(err)
+	}
+
+	id, pipe, err := controls.NewPipeFromEnds(nil, ptyPipe, r.pipes, req.AppID)
+	if err != nil {
+		return xfer.ResponseError(err)
+	}
+	pipe.OnClose(func() {
+		if err := cmd.Process.Kill(); err != nil {
+			log.Errorf("Error stopping host shell: %v", err)
+		}
+		if err := ptyPipe.Close(); err != nil {
+			log.Errorf("Error closing host shell's pty: %v", err)
+		}
+		log.Info("Host shell closed.")
+	})
+	go func() {
+		if err := cmd.Wait(); err != nil {
+			log.Errorf("Error waiting on host shell: %v", err)
+		}
+		pipe.Close()
+	}()
+
+	return xfer.Response{
+		Pipe:   id,
+		RawTTY: true,
+	}
+}

probe/host/controls_darwin.go

@@ -0,0 +1,5 @@
+package host
+
+func getHostShellCmd() []string {
+	return []string{"/bin/bash"}
+}

probe/host/controls_linux.go

@@ -0,0 +1,88 @@
+package host
+
+import (
+	"bytes"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/willdonnelly/passwd"
+)
+
+func getHostShellCmd() []string {
+	if isProbeContainerized() {
+		// Escape the container namespaces and jump into the ones from
+		// the host's init process.
+		// Note: There should be no need to enter into the host network
+		// and PID namespace because we should already already be there
+		// but it doesn't hurt.
+		readPasswdCmd := []string{"/usr/bin/nsenter", "-t1", "-m", "--no-fork", "cat", "/etc/passwd"}
+		uid, gid, shell := getRootUserDetails(readPasswdCmd)
+		return []string{
+			"/usr/bin/nsenter", "-t1", "-m", "-i", "-n", "-p", "--no-fork",
+			"--setuid", uid,
+			"--setgid", gid,
+			shell,
+		}
+	}
+
+	_, _, shell := getRootUserDetails([]string{"cat", "/etc/passwd"})
+	return []string{shell}
+}
+
+func getRootUserDetails(readPasswdCmd []string) (uid, gid, shell string) {
+	uid = "0"
+	gid = "0"
+	shell = "/bin/sh"
+
+	cmd := exec.Command(readPasswdCmd[0], readPasswdCmd[1:]...)
+	cmdBuffer := &bytes.Buffer{}
+	cmd.Stdout = cmdBuffer
+	if err := cmd.Run(); err != nil {
+		log.Warnf(
+			"getRootUserDetails(): error running read passwd command %q: %s",
+			strings.Join(readPasswdCmd, " "),
+			err,
+		)
+		return
+	}
+
+	entries, err := passwd.ParseReader(cmdBuffer)
+	if err != nil {
+		log.Warnf("getRootUserDetails(): error parsing passwd: %s", err)
+		return
+	}
+
+	entry, ok := entries["root"]
+	if !ok {
+		log.Warnf("getRootUserDetails(): no root entry in passwd")
+		return
+	}
+
+	return entry.Uid, entry.Gid, entry.Shell
+}
+
+func isProbeContainerized() bool {
+	// Figure out whether we are running in a container by checking if our
+	// mount namespace matches the one from init process. This works
+	// because, when containerized, the Scope probes run in the host's PID
+	// namespace (and if they weren't due to a configuration problem, we
+	// wouldn't have a way to escape the container anyhow).
+	var statT syscall.Stat_t
+
+	path := "/proc/self/ns/mnt"
+	if err := syscall.Stat(path, &statT); err != nil {
+		log.Warnf("isProbeContainerized(): stat() error on %q: %s", path, err)
+		return false
+	}
+	selfMountNamespaceID := statT.Ino
+
+	path = "/proc/1/ns/mnt"
+	if err := syscall.Stat(path, &statT); err != nil {
+		log.Warnf("isProbeContainerized(): stat() error on %q: %s", path, err)
+		return false
+	}
+
+	return selfMountNamespaceID != statT.Ino
+}

probe/host/reporter.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/weaveworks/scope/common/mtime"
+	"github.com/weaveworks/scope/probe/controls"
 	"github.com/weaveworks/scope/report"
 )
 
@@ -34,17 +35,25 @@ const (
 
 // Reporter generates Reports containing the host topology.
 type Reporter struct {
-	hostID   string
-	hostName string
+	hostID       string
+	hostName     string
+	probeID      string
+	pipes        controls.PipeClient
+	hostShellCmd []string
 }
 
 // NewReporter returns a Reporter which produces a report containing host
 // topology for this host.
-func NewReporter(hostID, hostName string) *Reporter {
-	return &Reporter{
-		hostID:   hostID,
-		hostName: hostName,
+func NewReporter(hostID, hostName, probeID string, pipes controls.PipeClient) *Reporter {
+	r := &Reporter{
+		hostID:       hostID,
+		hostName:     hostName,
+		probeID:      probeID,
+		pipes:        pipes,
+		hostShellCmd: getHostShellCmd(),
 	}
+	r.registerControls()
+	return r
 }
 
 // Name of this reporter, for metrics gathering
@@ -98,6 +107,7 @@ func (r *Reporter) Report() (report.Report, error) {
 	memoryUsage, max := GetMemoryUsageBytes()
 	metrics[MemoryUsage] = report.MakeMetric().Add(now, memoryUsage).WithMax(max)
 
+	metadata := map[string]string{report.ControlProbeID: r.probeID}
 	rep.Host.AddNode(report.MakeHostNodeID(r.hostID), report.MakeNodeWith(map[string]string{
 		Timestamp:     mtime.Now().UTC().Format(time.RFC3339Nano),
 		HostName:      r.hostName,
@@ -106,7 +116,18 @@ func (r *Reporter) Report() (report.Report, error) {
 		Uptime:        uptime.String(),
 	}).WithSets(report.EmptySets.
 		Add(LocalNetworks, report.MakeStringSet(localCIDRs...)),
-	).WithMetrics(metrics))
+	).WithMetrics(metrics).WithControls(ExecHost).WithLatests(metadata))
+
+	rep.Host.Controls.AddControl(report.Control{
+		ID:    ExecHost,
+		Human: "Exec shell",
+		Icon:  "fa-terminal",
+	})
 
 	return rep, nil
 }
+
+// Stop stops the reporter.
+func (r *Reporter) Stop() {
+	r.deregisterControls()
+}

probe/host/reporter_test.go

@@ -18,6 +18,7 @@ func TestReporter(t *testing.T) {
 		network   = "192.168.0.0/16"
 		hostID    = "hostid"
 		hostname  = "hostname"
+		probeID   = "abcdeadbeef"
 		timestamp = time.Now()
 		metrics   = report.Metrics{
 			host.Load1:       report.MakeMetric().Add(timestamp, 1.0),
@@ -57,7 +58,7 @@ func TestReporter(t *testing.T) {
 	host.GetMemoryUsageBytes = func() (float64, float64) { return 60.0, 100.0 }
 	host.GetLocalNetworks = func() ([]*net.IPNet, error) { return []*net.IPNet{ipnet}, nil }
 
-	rpt, err := host.NewReporter(hostID, hostname).Report()
+	rpt, err := host.NewReporter(hostID, hostname, probeID, nil).Report()
 	if err != nil {
 		t.Fatal(err)
 	}

prog/probe.go

@@ -140,9 +140,11 @@ func probeMain() {
 
 	p := probe.New(*spyInterval, *publishInterval, clients)
 	p.AddTicker(processCache)
+	hostReporter := host.NewReporter(hostID, hostName, probeID, clients)
+	defer hostReporter.Stop()
 	p.AddReporter(
 		endpointReporter,
-		host.NewReporter(hostID, hostName),
+		hostReporter,
 		process.NewReporter(processCache, hostID, process.GetDeltaTotalJiffies),
 	)
 	p.AddTagger(probe.NewTopologyTagger(), host.NewTagger(hostID))

vendor/github.com/kr/pty/License

@@ -0,0 +1,23 @@
+Copyright (c) 2011 Keith Rarick
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall
+be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/kr/pty/README.md

@@ -0,0 +1,36 @@
+# pty
+
+Pty is a Go package for using unix pseudo-terminals.
+
+## Install
+
+    go get github.com/kr/pty
+
+## Example
+
+```go
+package main
+
+import (
+	"github.com/kr/pty"
+	"io"
+	"os"
+	"os/exec"
+)
+
+func main() {
+	c := exec.Command("grep", "--color=auto", "bar")
+	f, err := pty.Start(c)
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		f.Write([]byte("foo\n"))
+		f.Write([]byte("bar\n"))
+		f.Write([]byte("baz\n"))
+		f.Write([]byte{4}) // EOT
+	}()
+	io.Copy(os.Stdout, f)
+}
+```

vendor/github.com/kr/pty/doc.go

@@ -0,0 +1,16 @@
+// Package pty provides functions for working with Unix terminals.
+package pty
+
+import (
+	"errors"
+	"os"
+)
+
+// ErrUnsupported is returned if a function is not
+// available on the current platform.
+var ErrUnsupported = errors.New("unsupported")
+
+// Opens a pty and its corresponding tty.
+func Open() (pty, tty *os.File, err error) {
+	return open()
+}

vendor/github.com/kr/pty/ioctl.go

@@ -0,0 +1,11 @@
+package pty
+
+import "syscall"
+
+func ioctl(fd, cmd, ptr uintptr) error {
+	_, _, e := syscall.Syscall(syscall.SYS_IOCTL, fd, cmd, ptr)
+	if e != 0 {
+		return e
+	}
+	return nil
+}

vendor/github.com/kr/pty/ioctl_bsd.go

@@ -0,0 +1,39 @@
+// +build darwin dragonfly freebsd netbsd openbsd
+
+package pty
+
+// from <sys/ioccom.h>
+const (
+	_IOC_VOID    uintptr = 0x20000000
+	_IOC_OUT     uintptr = 0x40000000
+	_IOC_IN      uintptr = 0x80000000
+	_IOC_IN_OUT  uintptr = _IOC_OUT | _IOC_IN
+	_IOC_DIRMASK         = _IOC_VOID | _IOC_OUT | _IOC_IN
+
+	_IOC_PARAM_SHIFT = 13
+	_IOC_PARAM_MASK  = (1 << _IOC_PARAM_SHIFT) - 1
+)
+
+func _IOC_PARM_LEN(ioctl uintptr) uintptr {
+	return (ioctl >> 16) & _IOC_PARAM_MASK
+}
+
+func _IOC(inout uintptr, group byte, ioctl_num uintptr, param_len uintptr) uintptr {
+	return inout | (param_len&_IOC_PARAM_MASK)<<16 | uintptr(group)<<8 | ioctl_num
+}
+
+func _IO(group byte, ioctl_num uintptr) uintptr {
+	return _IOC(_IOC_VOID, group, ioctl_num, 0)
+}
+
+func _IOR(group byte, ioctl_num uintptr, param_len uintptr) uintptr {
+	return _IOC(_IOC_OUT, group, ioctl_num, param_len)
+}
+
+func _IOW(group byte, ioctl_num uintptr, param_len uintptr) uintptr {
+	return _IOC(_IOC_IN, group, ioctl_num, param_len)
+}
+
+func _IOWR(group byte, ioctl_num uintptr, param_len uintptr) uintptr {
+	return _IOC(_IOC_IN_OUT, group, ioctl_num, param_len)
+}

vendor/github.com/kr/pty/mktypes.bash

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+GOOSARCH="${GOOS}_${GOARCH}"
+case "$GOOSARCH" in
+_* | *_ | _)
+	echo 'undefined $GOOS_$GOARCH:' "$GOOSARCH" 1>&2
+	exit 1
+	;;
+esac
+
+GODEFS="go tool cgo -godefs"
+
+$GODEFS types.go |gofmt > ztypes_$GOARCH.go
+
+case $GOOS in
+freebsd)
+	$GODEFS types_$GOOS.go |gofmt > ztypes_$GOOSARCH.go
+	;;
+esac

vendor/github.com/kr/pty/pty_darwin.go

@@ -0,0 +1,60 @@
+package pty
+
+import (
+	"errors"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func open() (pty, tty *os.File, err error) {
+	p, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = grantpt(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = unlockpt(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	t, err := os.OpenFile(sname, os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func ptsname(f *os.File) (string, error) {
+	n := make([]byte, _IOC_PARM_LEN(syscall.TIOCPTYGNAME))
+
+	err := ioctl(f.Fd(), syscall.TIOCPTYGNAME, uintptr(unsafe.Pointer(&n[0])))
+	if err != nil {
+		return "", err
+	}
+
+	for i, c := range n {
+		if c == 0 {
+			return string(n[:i]), nil
+		}
+	}
+	return "", errors.New("TIOCPTYGNAME string not NUL-terminated")
+}
+
+func grantpt(f *os.File) error {
+	return ioctl(f.Fd(), syscall.TIOCPTYGRANT, 0)
+}
+
+func unlockpt(f *os.File) error {
+	return ioctl(f.Fd(), syscall.TIOCPTYUNLK, 0)
+}

vendor/github.com/kr/pty/pty_freebsd.go

@@ -0,0 +1,73 @@
+package pty
+
+import (
+	"errors"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func posix_openpt(oflag int) (fd int, err error) {
+	r0, _, e1 := syscall.Syscall(syscall.SYS_POSIX_OPENPT, uintptr(oflag), 0, 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+func open() (pty, tty *os.File, err error) {
+	fd, err := posix_openpt(syscall.O_RDWR | syscall.O_CLOEXEC)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	p := os.NewFile(uintptr(fd), "/dev/pts")
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	t, err := os.OpenFile("/dev/"+sname, os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func isptmaster(fd uintptr) (bool, error) {
+	err := ioctl(fd, syscall.TIOCPTMASTER, 0)
+	return err == nil, err
+}
+
+var (
+	emptyFiodgnameArg fiodgnameArg
+	ioctl_FIODGNAME   = _IOW('f', 120, unsafe.Sizeof(emptyFiodgnameArg))
+)
+
+func ptsname(f *os.File) (string, error) {
+	master, err := isptmaster(f.Fd())
+	if err != nil {
+		return "", err
+	}
+	if !master {
+		return "", syscall.EINVAL
+	}
+
+	const n = _C_SPECNAMELEN + 1
+	var (
+		buf = make([]byte, n)
+		arg = fiodgnameArg{Len: n, Buf: (*byte)(unsafe.Pointer(&buf[0]))}
+	)
+	err = ioctl(f.Fd(), ioctl_FIODGNAME, uintptr(unsafe.Pointer(&arg)))
+	if err != nil {
+		return "", err
+	}
+
+	for i, c := range buf {
+		if c == 0 {
+			return string(buf[:i]), nil
+		}
+	}
+	return "", errors.New("FIODGNAME string not NUL-terminated")
+}

vendor/github.com/kr/pty/pty_linux.go

@@ -0,0 +1,46 @@
+package pty
+
+import (
+	"os"
+	"strconv"
+	"syscall"
+	"unsafe"
+)
+
+func open() (pty, tty *os.File, err error) {
+	p, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = unlockpt(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	t, err := os.OpenFile(sname, os.O_RDWR|syscall.O_NOCTTY, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func ptsname(f *os.File) (string, error) {
+	var n _C_uint
+	err := ioctl(f.Fd(), syscall.TIOCGPTN, uintptr(unsafe.Pointer(&n)))
+	if err != nil {
+		return "", err
+	}
+	return "/dev/pts/" + strconv.Itoa(int(n)), nil
+}
+
+func unlockpt(f *os.File) error {
+	var u _C_int
+	// use TIOCSPTLCK with a zero valued arg to clear the slave pty lock
+	return ioctl(f.Fd(), syscall.TIOCSPTLCK, uintptr(unsafe.Pointer(&u)))
+}

vendor/github.com/kr/pty/pty_unsupported.go

@@ -0,0 +1,11 @@
+// +build !linux,!darwin,!freebsd
+
+package pty
+
+import (
+	"os"
+)
+
+func open() (pty, tty *os.File, err error) {
+	return nil, nil, ErrUnsupported
+}

vendor/github.com/kr/pty/run.go

@@ -0,0 +1,32 @@
+package pty
+
+import (
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+// Start assigns a pseudo-terminal tty os.File to c.Stdin, c.Stdout,
+// and c.Stderr, calls c.Start, and returns the File of the tty's
+// corresponding pty.
+func Start(c *exec.Cmd) (pty *os.File, err error) {
+	pty, tty, err := Open()
+	if err != nil {
+		return nil, err
+	}
+	defer tty.Close()
+	c.Stdout = tty
+	c.Stdin = tty
+	c.Stderr = tty
+	if c.SysProcAttr == nil {
+		c.SysProcAttr = &syscall.SysProcAttr{}
+	}
+	c.SysProcAttr.Setctty = true
+	c.SysProcAttr.Setsid = true
+	err = c.Start()
+	if err != nil {
+		pty.Close()
+		return nil, err
+	}
+	return pty, err
+}

vendor/github.com/kr/pty/types.go

@@ -0,0 +1,10 @@
+// +build ignore
+
+package pty
+
+import "C"
+
+type (
+	_C_int  C.int
+	_C_uint C.uint
+)

vendor/github.com/kr/pty/types_freebsd.go

@@ -0,0 +1,15 @@
+// +build ignore
+
+package pty
+
+/*
+#include <sys/param.h>
+#include <sys/filio.h>
+*/
+import "C"
+
+const (
+	_C_SPECNAMELEN = C.SPECNAMELEN /* max length of devicename */
+)
+
+type fiodgnameArg C.struct_fiodgname_arg

vendor/github.com/kr/pty/util.go

@@ -0,0 +1,35 @@
+package pty
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// Getsize returns the number of rows (lines) and cols (positions
+// in each line) in terminal t.
+func Getsize(t *os.File) (rows, cols int, err error) {
+	var ws winsize
+	err = windowrect(&ws, t.Fd())
+	return int(ws.ws_row), int(ws.ws_col), err
+}
+
+type winsize struct {
+	ws_row    uint16
+	ws_col    uint16
+	ws_xpixel uint16
+	ws_ypixel uint16
+}
+
+func windowrect(ws *winsize, fd uintptr) error {
+	_, _, errno := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		fd,
+		syscall.TIOCGWINSZ,
+		uintptr(unsafe.Pointer(ws)),
+	)
+	if errno != 0 {
+		return syscall.Errno(errno)
+	}
+	return nil
+}

vendor/github.com/kr/pty/ztypes_386.go

@@ -0,0 +1,9 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_amd64.go

@@ -0,0 +1,9 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_arm.go

@@ -0,0 +1,9 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_arm64.go

@@ -0,0 +1,11 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+// +build arm64
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_freebsd_386.go

@@ -0,0 +1,13 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types_freebsd.go
+
+package pty
+
+const (
+	_C_SPECNAMELEN = 0x3f
+)
+
+type fiodgnameArg struct {
+	Len int32
+	Buf *byte
+}

vendor/github.com/kr/pty/ztypes_freebsd_amd64.go

@@ -0,0 +1,14 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types_freebsd.go
+
+package pty
+
+const (
+	_C_SPECNAMELEN = 0x3f
+)
+
+type fiodgnameArg struct {
+	Len       int32
+	Pad_cgo_0 [4]byte
+	Buf       *byte
+}

vendor/github.com/kr/pty/ztypes_freebsd_arm.go

@@ -0,0 +1,13 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types_freebsd.go
+
+package pty
+
+const (
+	_C_SPECNAMELEN = 0x3f
+)
+
+type fiodgnameArg struct {
+	Len int32
+	Buf *byte
+}

vendor/github.com/kr/pty/ztypes_ppc64.go

@@ -0,0 +1,11 @@
+// +build ppc64
+
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_ppc64le.go

@@ -0,0 +1,11 @@
+// +build ppc64le
+
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/kr/pty/ztypes_s390x.go

@@ -0,0 +1,11 @@
+// +build s390x
+
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types.go
+
+package pty
+
+type (
+	_C_int  int32
+	_C_uint uint32
+)

vendor/github.com/willdonnelly/passwd/README

@@ -0,0 +1,26 @@
+> godoc github.com/willdonnelly/passwd
+
+PACKAGE
+
+package passwd
+    import "github.com/willdonnelly/passwd"
+
+
+FUNCTIONS
+
+func Parse() (map[string]Entry, error)
+    Parse opens the '/etc/passwd' file and parses it into a map from
+    usernames to Entries
+
+
+TYPES
+
+type Entry struct {
+    Pass  string
+    Uid   string
+    Gid   string
+    Gecos string
+    Home  string
+    Shell string
+}
+    An Entry contains all the fields for a specific user

vendor/github.com/willdonnelly/passwd/passwd.go

@@ -0,0 +1,71 @@
+// Package passwd parsed content and files in form of /etc/passwd
+package passwd
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"os"
+	"strings"
+)
+
+// An Entry contains all the fields for a specific user
+type Entry struct {
+	Pass  string
+	Uid   string
+	Gid   string
+	Gecos string
+	Home  string
+	Shell string
+}
+
+// Parse opens the '/etc/passwd' file and parses it into a map from usernames
+// to Entries
+func Parse() (map[string]Entry, error) {
+	return ParseFile("/etc/passwd")
+}
+
+// ParseFile opens the file and parses it into a map from usernames to Entries
+func ParseFile(path string) (map[string]Entry, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	defer file.Close()
+
+	return ParseReader(file)
+}
+
+// ParseReader consumes the contents of r and parses it into a map from
+// usernames to Entries
+func ParseReader(r io.Reader) (map[string]Entry, error) {
+	lines := bufio.NewReader(r)
+	entries := make(map[string]Entry)
+	for {
+		line, _, err := lines.ReadLine()
+		if err != nil {
+			break
+		}
+		name, entry, err := parseLine(string(copyBytes(line)))
+		if err != nil {
+			return nil, err
+		}
+		entries[name] = entry
+	}
+	return entries, nil
+}
+
+func parseLine(line string) (string, Entry, error) {
+	fs := strings.Split(line, ":")
+	if len(fs) != 7 {
+		return "", Entry{}, errors.New("Unexpected number of fields in /etc/passwd")
+	}
+	return fs[0], Entry{fs[1], fs[2], fs[3], fs[4], fs[5], fs[6]}, nil
+}
+
+func copyBytes(x []byte) []byte {
+	y := make([]byte, len(x))
+	copy(y, x)
+	return y
+}

vendor/manifest

@@ -681,6 +681,12 @@
 			"revision": "77ed1c8a01217656d2080ad51981f6e99adaa177",
 			"branch": "master"
 		},
+		{
+			"importpath": "github.com/kr/pty",
+			"repository": "https://github.com/kr/pty",
+			"revision": "f7ee69f31298ecbe5d2b349c711e2547a617d398",
+			"branch": "master"
+		},
 		{
 			"importpath": "github.com/lsegal/gucumber",
 			"repository": "https://github.com/lsegal/gucumber",
@@ -871,6 +877,12 @@
 			"branch": "master",
 			"path": "/common"
 		},
+		{
+			"importpath": "github.com/willdonnelly/passwd",
+			"repository": "https://github.com/willdonnelly/passwd",
+			"revision": "7935dab3074ca1d47c8805e0230f8685116b6019",
+			"branch": "master"
+		},
 		{
 			"importpath": "golang.org/x/crypto/curve25519",
 			"repository": "https://go.googlesource.com/crypto",
@@ -1199,4 +1211,4 @@
 			"branch": "master"
 		}
 	]
-}
+}