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authorOpenShift Merge Robot <openshift-merge-robot@users.noreply.github.com>2019-04-10 08:51:26 -0700
committerGitHub <noreply@github.com>2019-04-10 08:51:26 -0700
commit1fb0a09591ae86b659dc87bd9e3f7fe29d8add8d (patch)
tree0f9df726674f9a28abbd08fc2aa9bfb71509ec1e
parent1701707dad4e4dba9d4331bd8917be28d138254d (diff)
parentfbcda7772d9fb7667be3a26fbabea0a7b5ea9a58 (diff)
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Merge pull request #2874 from baude/varlinkterm
Add the ability to attach remotely to a container
-rwxr-xr-xAPI.md21
-rw-r--r--cmd/podman/attach.go48
-rw-r--r--cmd/podman/commands.go2
-rw-r--r--cmd/podman/container.go1
-rw-r--r--cmd/podman/main.go1
-rw-r--r--cmd/podman/varlink/io.podman.varlink8
-rw-r--r--pkg/adapter/containers.go36
-rw-r--r--pkg/adapter/containers_remote.go152
-rw-r--r--pkg/varlinkapi/attach.go75
-rw-r--r--pkg/varlinkapi/containers.go16
-rw-r--r--pkg/varlinkapi/virtwriter/virtwriter.go155
11 files changed, 459 insertions, 56 deletions
diff --git a/API.md b/API.md
index 219e061d7..95507d189 100755
--- a/API.md
+++ b/API.md
@@ -3,6 +3,10 @@ Podman Service Interface and API description. The master version of this docume
in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in the upstream libpod repository.
## Index
+[func Attach(name: string) ](#Attach)
+
+[func AttachControl(name: string) ](#AttachControl)
+
[func BuildImage(build: BuildInfo) MoreResponse](#BuildImage)
[func BuildImageHierarchyMap(name: string) string](#BuildImageHierarchyMap)
@@ -135,6 +139,8 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
[func SendFile(type: string, length: int) string](#SendFile)
+[func Spec(name: string) string](#Spec)
+
[func StartContainer(name: string) string](#StartContainer)
[func StartPod(name: string) string](#StartPod)
@@ -252,6 +258,16 @@ in the [API.md](https://github.com/containers/libpod/blob/master/API.md) file in
[error WantsMoreRequired](#WantsMoreRequired)
## Methods
+### <a name="Attach"></a>func Attach
+<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
+
+method Attach(name: [string](https://godoc.org/builtin#string)) </div>
+
+### <a name="AttachControl"></a>func AttachControl
+<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
+
+method AttachControl(name: [string](https://godoc.org/builtin#string)) </div>
+
### <a name="BuildImage"></a>func BuildImage
<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
@@ -945,6 +961,11 @@ search results per registry.
method SendFile(type: [string](https://godoc.org/builtin#string), length: [int](https://godoc.org/builtin#int)) [string](https://godoc.org/builtin#string)</div>
Sendfile allows a remote client to send a file to the host
+### <a name="Spec"></a>func Spec
+<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
+
+method Spec(name: [string](https://godoc.org/builtin#string)) [string](https://godoc.org/builtin#string)</div>
+Spec returns the oci spec for a container. This call is for development of Podman only and generally should not be used.
### <a name="StartContainer"></a>func StartContainer
<div style="background-color: #E8E8E8; padding: 15px; margin: 10px; border-radius: 10px;">
diff --git a/cmd/podman/attach.go b/cmd/podman/attach.go
index f326f53c3..2fa05a3b1 100644
--- a/cmd/podman/attach.go
+++ b/cmd/podman/attach.go
@@ -1,11 +1,7 @@
package main
import (
- "os"
-
"github.com/containers/libpod/cmd/podman/cliconfig"
- "github.com/containers/libpod/cmd/podman/libpodruntime"
- "github.com/containers/libpod/libpod"
"github.com/containers/libpod/pkg/adapter"
"github.com/pkg/errors"
"github.com/spf13/cobra"
@@ -39,49 +35,21 @@ func init() {
flags.BoolVar(&attachCommand.SigProxy, "sig-proxy", true, "Proxy received signals to the process")
flags.BoolVarP(&attachCommand.Latest, "latest", "l", false, "Act on the latest container podman is aware of")
markFlagHiddenForRemoteClient("latest", flags)
+ // TODO allow for passing of a new deatch keys
+ markFlagHiddenForRemoteClient("detach-keys", flags)
}
func attachCmd(c *cliconfig.AttachValues) error {
- args := c.InputArgs
- var ctr *libpod.Container
-
if len(c.InputArgs) > 1 || (len(c.InputArgs) == 0 && !c.Latest) {
return errors.Errorf("attach requires the name or id of one running container or the latest flag")
}
-
- runtime, err := libpodruntime.GetRuntime(&c.PodmanCommand)
- if err != nil {
- return errors.Wrapf(err, "error creating libpod runtime")
- }
- defer runtime.Shutdown(false)
-
- if c.Latest {
- ctr, err = runtime.GetLatestContainer()
- } else {
- ctr, err = runtime.LookupContainer(args[0])
- }
-
- if err != nil {
- return errors.Wrapf(err, "unable to exec into %s", args[0])
+ if remoteclient && len(c.InputArgs) != 1 {
+ return errors.Errorf("attach requires the name or id of one running container")
}
-
- conState, err := ctr.State()
+ runtime, err := adapter.GetRuntime(&c.PodmanCommand)
if err != nil {
- return errors.Wrapf(err, "unable to determine state of %s", args[0])
- }
- if conState != libpod.ContainerStateRunning {
- return errors.Errorf("you can only attach to running containers")
- }
-
- inputStream := os.Stdin
- if c.NoStdin {
- inputStream = nil
+ return errors.Wrapf(err, "error creating runtime")
}
-
- // If the container is in a pod, also set to recursively start dependencies
- if err := adapter.StartAttachCtr(getContext(), ctr, os.Stdout, os.Stderr, inputStream, c.DetachKeys, c.SigProxy, false, ctr.PodID() != ""); err != nil && errors.Cause(err) != libpod.ErrDetach {
- return errors.Wrapf(err, "error attaching to container %s", ctr.ID())
- }
-
- return nil
+ defer runtime.Shutdown(false)
+ return runtime.Attach(getContext(), c)
}
diff --git a/cmd/podman/commands.go b/cmd/podman/commands.go
index 7c660f7cb..4d3df6896 100644
--- a/cmd/podman/commands.go
+++ b/cmd/podman/commands.go
@@ -11,7 +11,6 @@ const remoteclient = false
// Commands that the local client implements
func getMainCommands() []*cobra.Command {
rootCommands := []*cobra.Command{
- _attachCommand,
_commitCommand,
_execCommand,
_generateCommand,
@@ -47,7 +46,6 @@ func getImageSubCommands() []*cobra.Command {
func getContainerSubCommands() []*cobra.Command {
return []*cobra.Command{
- _attachCommand,
_checkpointCommand,
_cleanupCommand,
_commitCommand,
diff --git a/cmd/podman/container.go b/cmd/podman/container.go
index d1c42f673..380d1f250 100644
--- a/cmd/podman/container.go
+++ b/cmd/podman/container.go
@@ -50,6 +50,7 @@ var (
// Commands that are universally implemented.
containerCommands = []*cobra.Command{
+ _attachCommand,
_containerExistsCommand,
_contInspectSubCommand,
_diffCommand,
diff --git a/cmd/podman/main.go b/cmd/podman/main.go
index 7c765a0e0..35cef793d 100644
--- a/cmd/podman/main.go
+++ b/cmd/podman/main.go
@@ -38,6 +38,7 @@ var (
// Commands that the remote and local client have
// implemented.
var mainCommands = []*cobra.Command{
+ _attachCommand,
_buildCommand,
_diffCommand,
_createCommand,
diff --git a/cmd/podman/varlink/io.podman.varlink b/cmd/podman/varlink/io.podman.varlink
index d8905326c..ae830f3e6 100644
--- a/cmd/podman/varlink/io.podman.varlink
+++ b/cmd/podman/varlink/io.podman.varlink
@@ -658,8 +658,9 @@ method PauseContainer(name: string) -> (container: string)
# See also [PauseContainer](#PauseContainer).
method UnpauseContainer(name: string) -> (container: string)
-# This method has not be implemented yet.
-# method AttachToContainer() -> (notimplemented: NotImplemented)
+method Attach(name: string) -> ()
+
+method AttachControl(name: string) -> ()
# GetAttachSockets takes the name or ID of an existing container. It returns file paths for two sockets needed
# to properly communicate with a container. The first is the actual I/O socket that the container uses. The
@@ -1154,6 +1155,9 @@ method PodStateData(name: string) -> (config: string)
# This call is for the development of Podman only and should not be used.
method CreateFromCC(in: []string) -> (id: string)
+# Spec returns the oci spec for a container. This call is for development of Podman only and generally should not be used.
+method Spec(name: string) -> (config: string)
+
# Sendfile allows a remote client to send a file to the host
method SendFile(type: string, length: int) -> (file_handle: string)
diff --git a/pkg/adapter/containers.go b/pkg/adapter/containers.go
index 8ce506542..a9b3232e7 100644
--- a/pkg/adapter/containers.go
+++ b/pkg/adapter/containers.go
@@ -407,3 +407,39 @@ func (r *LocalRuntime) Ps(c *cliconfig.PsValues, opts shared.PsOptions) ([]share
logrus.Debugf("Setting maximum workers to %d", maxWorkers)
return shared.GetPsContainerOutput(r.Runtime, opts, c.Filter, maxWorkers)
}
+
+// Attach ...
+func (r *LocalRuntime) Attach(ctx context.Context, c *cliconfig.AttachValues) error {
+ var (
+ ctr *libpod.Container
+ err error
+ )
+
+ if c.Latest {
+ ctr, err = r.Runtime.GetLatestContainer()
+ } else {
+ ctr, err = r.Runtime.LookupContainer(c.InputArgs[0])
+ }
+
+ if err != nil {
+ return errors.Wrapf(err, "unable to exec into %s", c.InputArgs[0])
+ }
+
+ conState, err := ctr.State()
+ if err != nil {
+ return errors.Wrapf(err, "unable to determine state of %s", ctr.ID())
+ }
+ if conState != libpod.ContainerStateRunning {
+ return errors.Errorf("you can only attach to running containers")
+ }
+
+ inputStream := os.Stdin
+ if c.NoStdin {
+ inputStream = nil
+ }
+ // If the container is in a pod, also set to recursively start dependencies
+ if err := StartAttachCtr(ctx, ctr, os.Stdout, os.Stderr, inputStream, c.DetachKeys, c.SigProxy, false, ctr.PodID() != ""); err != nil && errors.Cause(err) != libpod.ErrDetach {
+ return errors.Wrapf(err, "error attaching to container %s", ctr.ID())
+ }
+ return nil
+}
diff --git a/pkg/adapter/containers_remote.go b/pkg/adapter/containers_remote.go
index 424c431df..1ae39749f 100644
--- a/pkg/adapter/containers_remote.go
+++ b/pkg/adapter/containers_remote.go
@@ -6,19 +6,25 @@ import (
"context"
"encoding/json"
"fmt"
+ "io"
+ "os"
"strconv"
"syscall"
"time"
"github.com/containers/libpod/cmd/podman/cliconfig"
"github.com/containers/libpod/cmd/podman/shared"
- "github.com/pkg/errors"
- "github.com/sirupsen/logrus"
-
iopodman "github.com/containers/libpod/cmd/podman/varlink"
"github.com/containers/libpod/libpod"
"github.com/containers/libpod/pkg/inspect"
+ "github.com/containers/libpod/pkg/varlinkapi/virtwriter"
+ "github.com/docker/docker/pkg/term"
+ "github.com/opencontainers/runtime-spec/specs-go"
+ "github.com/pkg/errors"
+ "github.com/sirupsen/logrus"
"github.com/varlink/go/varlink"
+ "golang.org/x/crypto/ssh/terminal"
+ "k8s.io/client-go/tools/remotecommand"
)
// Inspect returns an inspect struct from varlink
@@ -71,6 +77,19 @@ func (r *LocalRuntime) ContainerState(name string) (*libpod.ContainerState, erro
}
+// Spec obtains the container spec.
+func (r *LocalRuntime) Spec(name string) (*specs.Spec, error) {
+ reply, err := iopodman.Spec().Call(r.Conn, name)
+ if err != nil {
+ return nil, err
+ }
+ data := specs.Spec{}
+ if err := json.Unmarshal([]byte(reply), &data); err != nil {
+ return nil, err
+ }
+ return &data, nil
+}
+
// LookupContainer gets basic information about container over a varlink
// connection and then translates it to a *Container
func (r *LocalRuntime) LookupContainer(idOrName string) (*Container, error) {
@@ -79,10 +98,6 @@ func (r *LocalRuntime) LookupContainer(idOrName string) (*Container, error) {
return nil, err
}
config := r.Config(idOrName)
- if err != nil {
- return nil, err
- }
-
return &Container{
remoteContainer{
r,
@@ -322,18 +337,32 @@ func (r *LocalRuntime) CreateContainer(ctx context.Context, c *cliconfig.CreateV
// Run creates a container overvarlink and then starts it
func (r *LocalRuntime) Run(ctx context.Context, c *cliconfig.RunValues, exitCode int) (int, error) {
+ // FIXME
+ // podman-remote run -it alpine ls DOES NOT WORK YET
+ // podman-remote run -it alpine /bin/sh does, i suspect there is some sort of
+ // timing issue between the socket availability and terminal setup and the command
+ // being run.
+
// TODO the exit codes for run need to be figured out for remote connections
- if !c.Bool("detach") {
- return 0, errors.New("the remote client only supports detached containers")
- }
results := shared.NewIntermediateLayer(&c.PodmanCommand)
cid, err := iopodman.CreateContainer().Call(r.Conn, results.MakeVarlink())
if err != nil {
return 0, err
}
- fmt.Println(cid)
_, err = iopodman.StartContainer().Call(r.Conn, cid)
- return 0, err
+ if err != nil {
+ return 0, err
+ }
+ errChan, err := r.attach(ctx, os.Stdin, os.Stdout, cid)
+ if err != nil {
+ return 0, err
+ }
+ if c.Bool("detach") {
+ fmt.Println(cid)
+ return 0, err
+ }
+ finalError := <-errChan
+ return 0, finalError
}
func ReadExitFile(runtimeTmp, ctrID string) (int, error) {
@@ -411,3 +440,102 @@ func (r *LocalRuntime) Ps(c *cliconfig.PsValues, opts shared.PsOptions) ([]share
}
return psContainers, nil
}
+
+func (r *LocalRuntime) attach(ctx context.Context, stdin, stdout *os.File, cid string) (chan error, error) {
+ var (
+ oldTermState *term.State
+ )
+ errChan := make(chan error)
+ spec, err := r.Spec(cid)
+ if err != nil {
+ return nil, err
+ }
+ resize := make(chan remotecommand.TerminalSize)
+ haveTerminal := terminal.IsTerminal(int(os.Stdin.Fd()))
+
+ // Check if we are attached to a terminal. If we are, generate resize
+ // events, and set the terminal to raw mode
+ if haveTerminal && spec.Process.Terminal {
+ logrus.Debugf("Handling terminal attach")
+
+ subCtx, cancel := context.WithCancel(ctx)
+ defer cancel()
+
+ resizeTty(subCtx, resize)
+ oldTermState, err = term.SaveState(os.Stdin.Fd())
+ if err != nil {
+ return nil, errors.Wrapf(err, "unable to save terminal state")
+ }
+
+ logrus.SetFormatter(&RawTtyFormatter{})
+ term.SetRawTerminal(os.Stdin.Fd())
+
+ }
+
+ _, err = iopodman.Attach().Send(r.Conn, varlink.Upgrade, cid)
+ if err != nil {
+ restoreTerminal(oldTermState)
+ return nil, err
+ }
+
+ // These are the varlink sockets
+ reader := r.Conn.Reader
+ writer := r.Conn.Writer
+
+ // These are the special writers that encode input from the client.
+ varlinkStdinWriter := virtwriter.NewVirtWriteCloser(writer, virtwriter.ToStdin)
+ varlinkResizeWriter := virtwriter.NewVirtWriteCloser(writer, virtwriter.TerminalResize)
+
+ go func() {
+ // Read from the wire and direct to stdout or stderr
+ err := virtwriter.Reader(reader, stdout, os.Stderr, nil, nil)
+ defer restoreTerminal(oldTermState)
+ errChan <- err
+ }()
+
+ go func() {
+ for termResize := range resize {
+ b, err := json.Marshal(termResize)
+ if err != nil {
+ defer restoreTerminal(oldTermState)
+ errChan <- err
+ }
+ _, err = varlinkResizeWriter.Write(b)
+ if err != nil {
+ defer restoreTerminal(oldTermState)
+ errChan <- err
+ }
+ }
+ }()
+
+ // Takes stdinput and sends it over the wire after being encoded
+ go func() {
+ if _, err := io.Copy(varlinkStdinWriter, stdin); err != nil {
+ defer restoreTerminal(oldTermState)
+ errChan <- err
+ }
+
+ }()
+ return errChan, nil
+
+}
+
+// Attach to a remote terminal
+func (r *LocalRuntime) Attach(ctx context.Context, c *cliconfig.AttachValues) error {
+ ctr, err := r.LookupContainer(c.InputArgs[0])
+ if err != nil {
+ return nil
+ }
+ if ctr.state.State != libpod.ContainerStateRunning {
+ return errors.New("you can only attach to running containers")
+ }
+ inputStream := os.Stdin
+ if c.NoStdin {
+ inputStream = nil
+ }
+ errChan, err := r.attach(ctx, inputStream, os.Stdout, c.InputArgs[0])
+ if err != nil {
+ return err
+ }
+ return <-errChan
+}
diff --git a/pkg/varlinkapi/attach.go b/pkg/varlinkapi/attach.go
new file mode 100644
index 000000000..53c4d1ff6
--- /dev/null
+++ b/pkg/varlinkapi/attach.go
@@ -0,0 +1,75 @@
+// +build varlink
+
+package varlinkapi
+
+import (
+ "io"
+
+ "github.com/containers/libpod/cmd/podman/varlink"
+ "github.com/containers/libpod/libpod"
+ "github.com/containers/libpod/pkg/varlinkapi/virtwriter"
+ "k8s.io/client-go/tools/remotecommand"
+)
+
+// Close is method to close the writer
+
+// Attach ...
+func (i *LibpodAPI) Attach(call iopodman.VarlinkCall, name string) error {
+ var finalErr error
+ resize := make(chan remotecommand.TerminalSize)
+ errChan := make(chan error)
+
+ if !call.WantsUpgrade() {
+ return call.ReplyErrorOccurred("client must use upgraded connection to attach")
+ }
+ ctr, err := i.Runtime.LookupContainer(name)
+ if err != nil {
+ return call.ReplyErrorOccurred(err.Error())
+ }
+
+ // These are the varlink sockets
+ reader := call.Call.Reader
+ writer := call.Call.Writer
+
+ // This pipe is used to pass stdin from the client to the input stream
+ // once the msg has been "decoded"
+ pr, pw := io.Pipe()
+
+ stdoutWriter := virtwriter.NewVirtWriteCloser(writer, virtwriter.ToStdout)
+ // TODO if runc ever starts passing stderr, we can too
+ //stderrWriter := NewVirtWriteCloser(writer, ToStderr)
+
+ streams := libpod.AttachStreams{
+ OutputStream: stdoutWriter,
+ InputStream: pr,
+ // Runc eats the error stream
+ ErrorStream: stdoutWriter,
+ AttachInput: true,
+ AttachOutput: true,
+ // Runc eats the error stream
+ AttachError: true,
+ }
+
+ go func() {
+ if err := virtwriter.Reader(reader, nil, nil, pw, resize); err != nil {
+ errChan <- err
+ }
+ }()
+
+ go func() {
+ // TODO allow for customizable detach keys
+ if err := ctr.Attach(&streams, "", resize); err != nil {
+ errChan <- err
+ }
+ }()
+
+ select {
+ // Blocking on an error
+ case finalErr = <-errChan:
+ // Need to close up shop
+ _ = finalErr
+ }
+ quitWriter := virtwriter.NewVirtWriteCloser(writer, virtwriter.Quit)
+ _, err = quitWriter.Write([]byte("HANG-UP"))
+ return call.Writer.Flush()
+}
diff --git a/pkg/varlinkapi/containers.go b/pkg/varlinkapi/containers.go
index 816a72953..17792ccfe 100644
--- a/pkg/varlinkapi/containers.go
+++ b/pkg/varlinkapi/containers.go
@@ -634,6 +634,22 @@ func (i *LibpodAPI) GetContainerStatsWithHistory(call iopodman.VarlinkCall, prev
return call.ReplyGetContainerStatsWithHistory(cStats)
}
+// Spec ...
+func (i *LibpodAPI) Spec(call iopodman.VarlinkCall, name string) error {
+ ctr, err := i.Runtime.LookupContainer(name)
+ if err != nil {
+ return call.ReplyErrorOccurred(err.Error())
+ }
+
+ spec := ctr.Spec()
+ b, err := json.Marshal(spec)
+ if err != nil {
+ return call.ReplyErrorOccurred(err.Error())
+ }
+
+ return call.ReplySpec(string(b))
+}
+
// GetContainersLogs is the varlink endpoint to obtain one or more container logs
func (i *LibpodAPI) GetContainersLogs(call iopodman.VarlinkCall, names []string, follow, latest bool, since string, tail int64, timestamps bool) error {
var wg sync.WaitGroup
diff --git a/pkg/varlinkapi/virtwriter/virtwriter.go b/pkg/varlinkapi/virtwriter/virtwriter.go
new file mode 100644
index 000000000..3adaf6e17
--- /dev/null
+++ b/pkg/varlinkapi/virtwriter/virtwriter.go
@@ -0,0 +1,155 @@
+package virtwriter
+
+import (
+ "bufio"
+ "encoding/binary"
+ "encoding/json"
+ "errors"
+ "io"
+ "os"
+
+ "k8s.io/client-go/tools/remotecommand"
+)
+
+// SocketDest is the "key" to where IO should go on the varlink
+// multiplexed socket
+type SocketDest int
+
+const (
+ // ToStdout indicates traffic should go stdout
+ ToStdout SocketDest = iota
+ // ToStdin indicates traffic came from stdin
+ ToStdin SocketDest = iota
+ // ToStderr indicates traffuc should go to stderr
+ ToStderr SocketDest = iota
+ // TerminalResize indicates a terminal resize event has occurred
+ // and data should be passed to resizer
+ TerminalResize SocketDest = iota
+ // Quit and detach
+ Quit SocketDest = iota
+)
+
+// IntToSocketDest returns a socketdest based on integer input
+func IntToSocketDest(i int) SocketDest {
+ switch i {
+ case ToStdout.Int():
+ return ToStdout
+ case ToStderr.Int():
+ return ToStderr
+ case ToStdin.Int():
+ return ToStdin
+ case TerminalResize.Int():
+ return TerminalResize
+ case Quit.Int():
+ return Quit
+ default:
+ return ToStderr
+ }
+}
+
+// Int returns the integer representation of the socket dest
+func (sd SocketDest) Int() int {
+ return int(sd)
+}
+
+// VirtWriteCloser are writers for attach which include the dest
+// of the data
+type VirtWriteCloser struct {
+ writer *bufio.Writer
+ dest SocketDest
+}
+
+// NewVirtWriteCloser is a constructor
+func NewVirtWriteCloser(w *bufio.Writer, dest SocketDest) VirtWriteCloser {
+ return VirtWriteCloser{w, dest}
+}
+
+// Close is a required method for a writecloser
+func (v VirtWriteCloser) Close() error {
+ return nil
+}
+
+// Write prepends a header to the input message. The header is
+// 8bytes. Position one contains the destination. Positions
+// 5,6,7,8 are a big-endian encoded uint32 for len of the message.
+func (v VirtWriteCloser) Write(input []byte) (int, error) {
+ header := []byte{byte(v.dest), 0, 0, 0}
+ // Go makes us define the byte for big endian
+ mlen := make([]byte, 4)
+ binary.BigEndian.PutUint32(mlen, uint32(len(input)))
+ // append the message len to the header
+ msg := append(header, mlen...)
+ // append the message to the header
+ msg = append(msg, input...)
+ _, err := v.writer.Write(msg)
+ if err != nil {
+ return 0, err
+ }
+ err = v.writer.Flush()
+ return len(input), err
+}
+
+// Reader decodes the content that comes over the wire and directs it to the proper destination.
+func Reader(r *bufio.Reader, output, errput *os.File, input *io.PipeWriter, resize chan remotecommand.TerminalSize) error {
+ var saveb []byte
+ var eom int
+ for {
+ readb := make([]byte, 32*1024)
+ n, err := r.Read(readb)
+ // TODO, later may be worth checking in len of the read is 0
+ if err != nil {
+ return err
+ }
+ b := append(saveb, readb[0:n]...)
+ // no sense in reading less than the header len
+ for len(b) > 7 {
+ eom = int(binary.BigEndian.Uint32(b[4:8])) + 8
+ // The message and header are togther
+ if len(b) >= eom {
+ out := append([]byte{}, b[8:eom]...)
+
+ switch IntToSocketDest(int(b[0])) {
+ case ToStdout:
+ n, err := output.Write(out)
+ if err != nil {
+ return err
+ }
+ if n < len(out) {
+ return errors.New("short write error occurred on stdout")
+ }
+ case ToStderr:
+ n, err := errput.Write(out)
+ if err != nil {
+ return err
+ }
+ if n < len(out) {
+ return errors.New("short write error occurred on stderr")
+ }
+ case ToStdin:
+ n, err := input.Write(out)
+ if err != nil {
+ return err
+ }
+ if n < len(out) {
+ return errors.New("short write error occurred on stdin")
+ }
+ case TerminalResize:
+ // Resize events come over in bytes, need to be reserialized
+ resizeEvent := remotecommand.TerminalSize{}
+ if err := json.Unmarshal(out, &resizeEvent); err != nil {
+ return err
+ }
+ resize <- resizeEvent
+ case Quit:
+ return nil
+ }
+ b = b[eom:]
+ } else {
+ // We do not have the header and full message, need to slurp again
+ saveb = b
+ break
+ }
+ }
+ }
+ return nil
+}