Add support for attach to kubectl

contrib/completions/bash/kubectl

@@ -505,6 +505,29 @@ _kubectl_scale()
     must_have_one_noun=()
 }
 
+_kubectl_attach()
+{
+    last_command="kubectl_attach"
+    commands=()
+
+    flags=()
+    two_word_flags=()
+    flags_with_completion=()
+    flags_completion=()
+
+    flags+=("--container=")
+    two_word_flags+=("-c")
+    flags+=("--help")
+    flags+=("-h")
+    flags+=("--stdin")
+    flags+=("-i")
+    flags+=("--tty")
+    flags+=("-t")
+
+    must_have_one_flag=()
+    must_have_one_noun=()
+}
+
 _kubectl_exec()
 {
     last_command="kubectl_exec"
@@ -946,6 +969,7 @@ _kubectl()
     commands+=("logs")
     commands+=("rolling-update")
     commands+=("scale")
+    commands+=("attach")
     commands+=("exec")
     commands+=("port-forward")
     commands+=("proxy")

docs/man/man1/.files_generated

 kubectl-api-versions.1
+kubectl-attach.1
 kubectl-cluster-info.1
 kubectl-config-set-cluster.1
 kubectl-config-set-context.1

docs/man/man1/kubectl-attach.1

+.TH "KUBERNETES" "1" " kubernetes User Manuals" "Eric Paris" "Jan 2015"  ""
+
+
+.SH NAME
+.PP
+kubectl attach \- Attach to a running container.
+
+
+.SH SYNOPSIS
+.PP
+\fBkubectl attach\fP [OPTIONS]
+
+
+.SH DESCRIPTION
+.PP
+Attach to a a process that is already running inside an existing container.
+
+
+.SH OPTIONS
+.PP
+\fB\-c\fP, \fB\-\-container\fP=""
+    Container name
+
+.PP
+\fB\-h\fP, \fB\-\-help\fP=false
+    help for attach
+
+.PP
+\fB\-i\fP, \fB\-\-stdin\fP=false
+    Pass stdin to the container
+
+.PP
+\fB\-t\fP, \fB\-\-tty\fP=false
+    Stdin is a TTY
+
+
+.SH OPTIONS INHERITED FROM PARENT COMMANDS
+.PP
+\fB\-\-alsologtostderr\fP=false
+    log to standard error as well as files
+
+.PP
+\fB\-\-api\-version\fP=""
+    The API version to use when talking to the server
+
+.PP
+\fB\-\-certificate\-authority\fP=""
+    Path to a cert. file for the certificate authority.
+
+.PP
+\fB\-\-client\-certificate\fP=""
+    Path to a client key file for TLS.
+
+.PP
+\fB\-\-client\-key\fP=""
+    Path to a client key file for TLS.
+
+.PP
+\fB\-\-cluster\fP=""
+    The name of the kubeconfig cluster to use
+
+.PP
+\fB\-\-context\fP=""
+    The name of the kubeconfig context to use
+
+.PP
+\fB\-\-insecure\-skip\-tls\-verify\fP=false
+    If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
+
+.PP
+\fB\-\-kubeconfig\fP=""
+    Path to the kubeconfig file to use for CLI requests.
+
+.PP
+\fB\-\-log\-backtrace\-at\fP=:0
+    when logging hits line file:N, emit a stack trace
+
+.PP
+\fB\-\-log\-dir\fP=""
+    If non\-empty, write log files in this directory
+
+.PP
+\fB\-\-log\-flush\-frequency\fP=5s
+    Maximum number of seconds between log flushes
+
+.PP
+\fB\-\-logtostderr\fP=true
+    log to standard error instead of files
+
+.PP
+\fB\-\-match\-server\-version\fP=false
+    Require server version to match client version
+
+.PP
+\fB\-\-namespace\fP=""
+    If present, the namespace scope for this CLI request.
+
+.PP
+\fB\-\-password\fP=""
+    Password for basic authentication to the API server.
+
+.PP
+\fB\-s\fP, \fB\-\-server\fP=""
+    The address and port of the Kubernetes API server
+
+.PP
+\fB\-\-stderrthreshold\fP=2
+    logs at or above this threshold go to stderr
+
+.PP
+\fB\-\-token\fP=""
+    Bearer token for authentication to the API server.
+
+.PP
+\fB\-\-user\fP=""
+    The name of the kubeconfig user to use
+
+.PP
+\fB\-\-username\fP=""
+    Username for basic authentication to the API server.
+
+.PP
+\fB\-\-v\fP=0
+    log level for V logs
+
+.PP
+\fB\-\-validate\fP=false
+    If true, use a schema to validate the input before sending it
+
+.PP
+\fB\-\-vmodule\fP=
+    comma\-separated list of pattern=N settings for file\-filtered logging
+
+
+.SH EXAMPLE
+.PP
+.RS
+
+.nf
+// get output from running pod 123456\-7890, using the first container by default
+$ kubectl attach 123456\-7890
+	
+// get output from ruby\-container from pod 123456\-7890
+$ kubectl attach 123456\-7890 \-c ruby\-container date
+
+// switch to raw terminal mode, sends stdin to 'bash' in ruby\-container from pod 123456\-780
+// and sends stdout/stderr from 'bash' back to the client
+$ kubectl attach 123456\-7890 \-c ruby\-container \-i \-t
+
+.fi
+.RE
+
+
+.SH SEE ALSO
+.PP
+\fBkubectl(1)\fP,
+
+
+.SH HISTORY
+.PP
+January 2015, Originally compiled by Eric Paris (eparis at redhat dot com) based on the kubernetes source material, but hopefully they have been automatically generated since!

docs/man/man1/kubectl.1

@@ -124,7 +124,7 @@ Find more information at
 
 .SH SEE ALSO
 .PP
-\fBkubectl\-get(1)\fP, \fBkubectl\-describe(1)\fP, \fBkubectl\-create(1)\fP, \fBkubectl\-replace(1)\fP, \fBkubectl\-patch(1)\fP, \fBkubectl\-delete(1)\fP, \fBkubectl\-namespace(1)\fP, \fBkubectl\-logs(1)\fP, \fBkubectl\-rolling\-update(1)\fP, \fBkubectl\-scale(1)\fP, \fBkubectl\-exec(1)\fP, \fBkubectl\-port\-forward(1)\fP, \fBkubectl\-proxy(1)\fP, \fBkubectl\-run(1)\fP, \fBkubectl\-stop(1)\fP, \fBkubectl\-expose(1)\fP, \fBkubectl\-label(1)\fP, \fBkubectl\-config(1)\fP, \fBkubectl\-cluster\-info(1)\fP, \fBkubectl\-api\-versions(1)\fP, \fBkubectl\-version(1)\fP,
+\fBkubectl\-get(1)\fP, \fBkubectl\-describe(1)\fP, \fBkubectl\-create(1)\fP, \fBkubectl\-replace(1)\fP, \fBkubectl\-patch(1)\fP, \fBkubectl\-delete(1)\fP, \fBkubectl\-namespace(1)\fP, \fBkubectl\-logs(1)\fP, \fBkubectl\-rolling\-update(1)\fP, \fBkubectl\-scale(1)\fP, \fBkubectl\-attach(1)\fP, \fBkubectl\-exec(1)\fP, \fBkubectl\-port\-forward(1)\fP, \fBkubectl\-proxy(1)\fP, \fBkubectl\-run(1)\fP, \fBkubectl\-stop(1)\fP, \fBkubectl\-expose(1)\fP, \fBkubectl\-label(1)\fP, \fBkubectl\-config(1)\fP, \fBkubectl\-cluster\-info(1)\fP, \fBkubectl\-api\-versions(1)\fP, \fBkubectl\-version(1)\fP,
 
 
 .SH HISTORY

docs/user-guide/docker-cli-to-kubectl.md

@@ -41,6 +41,7 @@ In this doc, we introduce the Kubernetes command line to for interacting with th
 - [kubectl for docker users](#kubectl-for-docker-users)
       - [docker run](#docker-run)
       - [docker ps](#docker-ps)
+      - [docker attach](#docker-attach)
       - [docker exec](#docker-exec)
       - [docker logs](#docker-logs)
       - [docker stop and docker rm](#docker-stop-and-docker-rm)
@@ -99,6 +100,31 @@ NAME              READY     STATUS    RESTARTS   AGE
 nginx-app-5jyvm   1/1       Running   0          1h
 ```
 
+#### docker attach
+
+How do I attach to a process that is already running in a container?  Checkout [kubectl attach](kubectl/kubectl_attach.md)
+
+With docker:
+
+```console
+$ docker ps
+CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                         NAMES
+a9ec34d98787        nginx               "nginx -g 'daemon of   8 minutes ago       Up 8 minutes        0.0.0.0:80->80/tcp, 443/tcp   nginx-app
+$ docker attach -it a9ec34d98787
+...
+```
+
+With kubectl:
+
+```console
+$ kubectl get pods
+NAME              READY     STATUS    RESTARTS   AGE
+nginx-app-5jyvm   1/1       Running   0          10m
+$ kubectl attach -it nginx-app-5jyvm
+...
+
+```
+
 #### docker exec
 
 How do I execute a command in a container? Checkout [kubectl exec](kubectl/kubectl_exec.md).
@@ -106,21 +132,25 @@ How do I execute a command in a container? Checkout [kubectl exec](kubectl/kubec
 With docker:
 
 ```console
+
 $ docker ps
 CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                         NAMES
 a9ec34d98787        nginx               "nginx -g 'daemon of   8 minutes ago       Up 8 minutes        0.0.0.0:80->80/tcp, 443/tcp   nginx-app
 $ docker exec a9ec34d98787 cat /etc/hostname
 a9ec34d98787
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl get po
 NAME              READY     STATUS    RESTARTS   AGE
 nginx-app-5jyvm   1/1       Running   0          10m
 $ kubectl exec nginx-app-5jyvm -- cat /etc/hostname
 nginx-app-5jyvm
+
 ```
 
 What about interactive commands?
@@ -129,15 +159,21 @@ What about interactive commands?
 With docker:
 
 ```console
+
 $ docker exec -ti a9ec34d98787 /bin/sh
+
 # exit
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl exec -ti nginx-app-5jyvm -- /bin/sh      
+
 # exit
+
 ```
 
 For more information see [Getting into containers](getting-into-containers.md).
@@ -150,25 +186,31 @@ How do I follow stdout/stderr of a running process? Checkout [kubectl logs](kube
 With docker:
 
 ```console
+
 $ docker logs -f a9e
 192.168.9.1 - - [14/Jul/2015:01:04:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"
 192.168.9.1 - - [14/Jul/2015:01:04:03 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl logs -f nginx-app-zibvs
 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
 10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
+
 ```
 
 Now's a good time to mention slight difference between pods and containers; by default pods will not terminate if their processes exit. Instead it will restart the process. This is similar to the docker run option `--restart=always` with one major difference. In docker, the output for each invocation of the process is concatenated but for Kubernetes, each invokation is separate. To see the output from a prevoius run in Kubernetes, do this:
 
 ```console
+
 $ kubectl logs --previous nginx-app-zibvs
 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
 10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
+
 ```
 
 See [Logging](logging.md) for more information.
@@ -180,6 +222,7 @@ How do I stop and delete a running process? Checkout [kubectl delete](kubectl/ku
 With docker
 
 ```console
+
 $ docker ps
 CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                         NAMES
 a9ec34d98787        nginx               "nginx -g 'daemon of   22 hours ago        Up 22 hours         0.0.0.0:80->80/tcp, 443/tcp   nginx-app
@@ -187,11 +230,13 @@ $ docker stop a9ec34d98787
 a9ec34d98787
 $ docker rm a9ec34d98787
 a9ec34d98787
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl get rc nginx-app
 CONTROLLER   CONTAINER(S)   IMAGE(S)   SELECTOR        REPLICAS
 nginx-app    nginx-app      nginx      run=nginx-app   1
@@ -203,6 +248,7 @@ NAME              READY     STATUS    RESTARTS   AGE
 nginx-app-aualv   1/1       Running   0          16s
 $ kubectl get po
 NAME      READY     STATUS    RESTARTS   AGE
+
 ```
 
 Notice that we don't delete the pod directly. With kubectl we want to delete the replication controller that owns the pod. If we delete the pod directly, the replication controller will recreate the pod.
@@ -218,6 +264,7 @@ How do I get the version of my client and server? Checkout [kubectl version](kub
 With docker:
 
 ```console
+
 $ docker version
 Client version: 1.7.0
 Client API version: 1.19
@@ -229,14 +276,17 @@ Server API version: 1.19
 Go version (server): go1.4.2
 Git commit (server): 0baf609
 OS/Arch (server): linux/amd64
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl version
 Client Version: version.Info{Major:"0", Minor:"20.1", GitVersion:"v0.20.1", GitCommit:"", GitTreeState:"not a git tree"}
 Server Version: version.Info{Major:"0", Minor:"21+", GitVersion:"v0.21.1-411-g32699e873ae1ca-dirty", GitCommit:"32699e873ae1caa01812e41de7eab28df4358ee4", GitTreeState:"dirty"}
+
 ```
 
 #### docker info
@@ -246,6 +296,7 @@ How do I get miscellaneous info about my environment and configuration? Checkout
 With docker:
 
 ```console
+
 $ docker info
 Containers: 40
 Images: 168
@@ -263,11 +314,13 @@ Total Memory: 31.32 GiB
 Name: k8s-is-fun.mtv.corp.google.com
 ID: ADUV:GCYR:B3VJ:HMPO:LNPQ:KD5S:YKFQ:76VN:IANZ:7TFV:ZBF4:BYJO
 WARNING: No swap limit support
+
 ```
 
 With kubectl:
 
 ```console
+
 $ kubectl cluster-info
 Kubernetes master is running at https://108.59.85.141
 KubeDNS is running at https://108.59.85.141/api/v1/proxy/namespaces/kube-system/services/kube-dns
@@ -275,6 +328,7 @@ KubeUI is running at https://108.59.85.141/api/v1/proxy/namespaces/kube-system/s
 Grafana is running at https://108.59.85.141/api/v1/proxy/namespaces/kube-system/services/monitoring-grafana
 Heapster is running at https://108.59.85.141/api/v1/proxy/namespaces/kube-system/services/monitoring-heapster
 InfluxDB is running at https://108.59.85.141/api/v1/proxy/namespaces/kube-system/services/monitoring-influxdb
+
 ```
 
 

docs/user-guide/kubectl/.files_generated

 kubectl.md
 kubectl_api-versions.md
+kubectl_attach.md
 kubectl_cluster-info.md
 kubectl_config.md
 kubectl_config_set-cluster.md

docs/user-guide/kubectl/kubectl.md

@@ -79,6 +79,7 @@ kubectl
 ### SEE ALSO
 
 * [kubectl api-versions](kubectl_api-versions.md)	 - Print available API versions.
+* [kubectl attach](kubectl_attach.md)	 - Attach to a running container.
 * [kubectl cluster-info](kubectl_cluster-info.md)	 - Display cluster info
 * [kubectl config](kubectl_config.md)	 - config modifies kubeconfig files
 * [kubectl create](kubectl_create.md)	 - Create a resource by filename or stdin
@@ -100,7 +101,7 @@ kubectl
 * [kubectl stop](kubectl_stop.md)	 - Deprecated: Gracefully shut down a resource by name or filename.
 * [kubectl version](kubectl_version.md)	 - Print the client and server version information.
 
-###### Auto generated by spf13/cobra at 2015-07-29 09:18:59.541696918 +0000 UTC
+###### Auto generated by spf13/cobra at 2015-07-30 03:45:17.319803488 +0000 UTC
 
 
 <!-- BEGIN MUNGE: GENERATED_ANALYTICS -->

docs/user-guide/kubectl/kubectl_attach.md

+<!-- BEGIN MUNGE: UNVERSIONED_WARNING -->
+
+<!-- BEGIN STRIP_FOR_RELEASE -->
+
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+<img src="http://kubernetes.io/img/warning.png" alt="WARNING"
+     width="25" height="25">
+
+<h2>PLEASE NOTE: This document applies to the HEAD of the source tree</h2>
+
+If you are using a released version of Kubernetes, you should
+refer to the docs that go with that version.
+
+<strong>
+The latest 1.0.x release of this document can be found
+[here](http://releases.k8s.io/release-1.0/docs/user-guide/kubectl/kubectl_attach.md).
+
+Documentation for other releases can be found at
+[releases.k8s.io](http://releases.k8s.io).
+</strong>
+--
+
+<!-- END STRIP_FOR_RELEASE -->
+
+<!-- END MUNGE: UNVERSIONED_WARNING -->
+
+## kubectl attach
+
+Attach to a running container.
+
+### Synopsis
+
+
+Attach to a a process that is already running inside an existing container.
+
+```
+kubectl attach POD -c CONTAINER
+```
+
+### Examples
+
+```
+// get output from running pod 123456-7890, using the first container by default
+$ kubectl attach 123456-7890
+	
+// get output from ruby-container from pod 123456-7890
+$ kubectl attach 123456-7890 -c ruby-container date
+
+// switch to raw terminal mode, sends stdin to 'bash' in ruby-container from pod 123456-780
+// and sends stdout/stderr from 'bash' back to the client
+$ kubectl attach 123456-7890 -c ruby-container -i -t
+```
+
+### Options
+
+```
+  -c, --container="": Container name
+  -h, --help=false: help for attach
+  -i, --stdin=false: Pass stdin to the container
+  -t, --tty=false: Stdin is a TTY
+```
+
+### Options inherited from parent commands
+
+```
+      --alsologtostderr=false: log to standard error as well as files
+      --api-version="": The API version to use when talking to the server
+      --certificate-authority="": Path to a cert. file for the certificate authority.
+      --client-certificate="": Path to a client key file for TLS.
+      --client-key="": Path to a client key file for TLS.
+      --cluster="": The name of the kubeconfig cluster to use
+      --context="": The name of the kubeconfig context to use
+      --insecure-skip-tls-verify=false: If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
+      --kubeconfig="": Path to the kubeconfig file to use for CLI requests.
+      --log-backtrace-at=:0: when logging hits line file:N, emit a stack trace
+      --log-dir=: If non-empty, write log files in this directory
+      --log-flush-frequency=5s: Maximum number of seconds between log flushes
+      --logtostderr=true: log to standard error instead of files
+      --match-server-version=false: Require server version to match client version
+      --namespace="": If present, the namespace scope for this CLI request.
+      --password="": Password for basic authentication to the API server.
+  -s, --server="": The address and port of the Kubernetes API server
+      --stderrthreshold=2: logs at or above this threshold go to stderr
+      --token="": Bearer token for authentication to the API server.
+      --user="": The name of the kubeconfig user to use
+      --username="": Username for basic authentication to the API server.
+      --v=0: log level for V logs
+      --validate=false: If true, use a schema to validate the input before sending it
+      --vmodule=: comma-separated list of pattern=N settings for file-filtered logging
+```
+
+### SEE ALSO
+
+* [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
+
+###### Auto generated by spf13/cobra at 2015-07-30 17:45:25.860905122 +0000 UTC
+
+
+<!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
+[![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl_attach.md?pixel)]()
+<!-- END MUNGE: GENERATED_ANALYTICS -->

pkg/client/remotecommand/remotecommand.go

@@ -25,6 +25,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/conversion/queryparams"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/httpstream"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/httpstream/spdy"
 	"github.com/golang/glog"
@@ -40,30 +41,72 @@ func (u *defaultUpgrader) upgrade(req *client.Request, config *client.Config) (h
 	return req.Upgrade(config, spdy.NewRoundTripper)
 }
 
+type Streamer struct {
+	req    *client.Request
+	config *client.Config
+	stdin  io.Reader
+	stdout io.Writer
+	stderr io.Writer
+	tty    bool
+
+	upgrader upgrader
+}
+
 // Executor executes a command on a pod container
 type Executor struct {
-	req     *client.Request
-	config  *client.Config
+	Streamer
 	command []string
-	stdin   io.Reader
-	stdout  io.Writer
-	stderr  io.Writer
-	tty     bool
-
-	upgrader upgrader
 }
 
 // New creates a new RemoteCommandExecutor
 func New(req *client.Request, config *client.Config, command []string, stdin io.Reader, stdout, stderr io.Writer, tty bool) *Executor {
 	return &Executor{
-		req:     req,
-		config:  config,
 		command: command,
-		stdin:   stdin,
-		stdout:  stdout,
-		stderr:  stderr,
-		tty:     tty,
+		Streamer: Streamer{
+			req:    req,
+			config: config,
+			stdin:  stdin,
+			stdout: stdout,
+			stderr: stderr,
+			tty:    tty,
+		},
+	}
+}
+
+type Attach struct {
+	Streamer
+}
+
+// NewAttach creates a new RemoteAttach
+func NewAttach(req *client.Request, config *client.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) *Attach {
+	return &Attach{
+		Streamer: Streamer{
+			req:    req,
+			config: config,
+			stdin:  stdin,
+			stdout: stdout,
+			stderr: stderr,
+			tty:    tty,
+		},
+	}
+}
+
+// Execute sends a remote command execution request, upgrading the
+// connection and creating streams to represent stdin/stdout/stderr. Data is
+// copied between these streams and the supplied stdin/stdout/stderr parameters.
+func (e *Attach) Execute() error {
+	opts := api.PodAttachOptions{
+		Stdin:  (e.stdin != nil),
+		Stdout: (e.stdout != nil),
+		Stderr: (!e.tty && e.stderr != nil),
+		TTY:    e.tty,
 	}
+
+	if err := e.setupRequestParameters(&opts); err != nil {
+		return err
+	}
+
+	return e.doStream()
 }
 
 // Execute sends a remote command execution request, upgrading the
@@ -78,7 +121,15 @@ func (e *Executor) Execute() error {
 		Command: e.command,
 	}
 
-	versioned, err := api.Scheme.ConvertToVersion(&opts, e.config.Version)
+	if err := e.setupRequestParameters(&opts); err != nil {
+		return err
+	}
+
+	return e.doStream()
+}
+
+func (e *Streamer) setupRequestParameters(obj runtime.Object) error {
+	versioned, err := api.Scheme.ConvertToVersion(obj, e.config.Version)
 	if err != nil {
 		return err
 	}
@@ -91,7 +142,10 @@ func (e *Executor) Execute() error {
 			e.req.Param(k, vv)
 		}
 	}
+	return nil
+}
 
+func (e *Streamer) doStream() error {
 	if e.upgrader == nil {
 		e.upgrader = &defaultUpgrader{}
 	}
@@ -134,7 +188,7 @@ func (e *Executor) Execute() error {
 	}()
 	defer errorStream.Reset()
 
-	if opts.Stdin {
+	if e.stdin != nil {
 		headers.Set(api.StreamType, api.StreamTypeStdin)
 		remoteStdin, err := conn.CreateStream(headers)
 		if err != nil {
@@ -151,7 +205,7 @@ func (e *Executor) Execute() error {
 	waitCount := 0
 	completedStreams := 0
 
-	if opts.Stdout {
+	if e.stdout != nil {
 		waitCount++
 		headers.Set(api.StreamType, api.StreamTypeStdout)
 		remoteStdout, err := conn.CreateStream(headers)
@@ -162,7 +216,7 @@ func (e *Executor) Execute() error {
 		go cp(api.StreamTypeStdout, e.stdout, remoteStdout)
 	}
 
-	if opts.Stderr && !e.tty {
+	if e.stderr != nil && !e.tty {
 		waitCount++
 		headers.Set(api.StreamType, api.StreamTypeStderr)
 		remoteStderr, err := conn.CreateStream(headers)

pkg/client/remotecommand/remotecommand_test.go

@@ -190,3 +190,80 @@ func TestRequestExecuteRemoteCommand(t *testing.T) {
 		server.Close()
 	}
 }
+
+// TODO: this test is largely cut and paste, refactor to share code
+func TestRequestAttachRemoteCommand(t *testing.T) {
+	testCases := []struct {
+		Stdin  string
+		Stdout string
+		Stderr string
+		Error  string
+		Tty    bool
+	}{
+		{
+			Error: "bail",
+		},
+		{
+			Stdin:  "a",
+			Stdout: "b",
+			Stderr: "c",
+		},
+		{
+			Stdin:  "a",
+			Stdout: "b",
+			Tty:    true,
+		},
+	}
+
+	for i, testCase := range testCases {
+		localOut := &bytes.Buffer{}
+		localErr := &bytes.Buffer{}
+
+		server := httptest.NewServer(fakeExecServer(t, i, testCase.Stdin, testCase.Stdout, testCase.Stderr, testCase.Error, testCase.Tty))
+
+		url, _ := url.ParseRequestURI(server.URL)
+		c := client.NewRESTClient(url, "x", nil, -1, -1)
+		req := c.Post().Resource("testing")
+
+		conf := &client.Config{
+			Host: server.URL,
+		}
+		e := NewAttach(req, conf, strings.NewReader(testCase.Stdin), localOut, localErr, testCase.Tty)
+		//e.upgrader = testCase.Upgrader
+		err := e.Execute()
+		hasErr := err != nil
+
+		if len(testCase.Error) > 0 {
+			if !hasErr {
+				t.Errorf("%d: expected an error", i)
+			} else {
+				if e, a := testCase.Error, err.Error(); !strings.Contains(a, e) {
+					t.Errorf("%d: expected error stream read '%v', got '%v'", i, e, a)
+				}
+			}
+
+			server.Close()
+			continue
+		}
+
+		if hasErr {
+			t.Errorf("%d: unexpected error: %v", i, err)
+			server.Close()
+			continue
+		}
+
+		if len(testCase.Stdout) > 0 {
+			if e, a := testCase.Stdout, localOut; e != a.String() {
+				t.Errorf("%d: expected stdout data '%s', got '%s'", i, e, a)
+			}
+		}
+
+		if testCase.Stderr != "" {
+			if e, a := testCase.Stderr, localErr; e != a.String() {
+				t.Errorf("%d: expected stderr data '%s', got '%s'", i, e, a)
+			}
+		}
+
+		server.Close()
+	}
+}

pkg/kubectl/cmd/attach.go

+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/remotecommand"
+	cmdutil "github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl/cmd/util"
+	"github.com/docker/docker/pkg/term"
+	"github.com/golang/glog"
+	"github.com/spf13/cobra"
+)
+
+const (
+	attach_example = `// get output from running pod 123456-7890, using the first container by default
+$ kubectl attach 123456-7890
+	
+// get output from ruby-container from pod 123456-7890
+$ kubectl attach 123456-7890 -c ruby-container date
+
+// switch to raw terminal mode, sends stdin to 'bash' in ruby-container from pod 123456-780
+// and sends stdout/stderr from 'bash' back to the client
+$ kubectl attach 123456-7890 -c ruby-container -i -t`
+)
+
+func NewCmdAttach(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer) *cobra.Command {
+	options := &AttachOptions{
+		In:  cmdIn,
+		Out: cmdOut,
+		Err: cmdErr,
+
+		Attach: &DefaultRemoteAttach{},
+	}
+	cmd := &cobra.Command{
+		Use:     "attach POD -c CONTAINER",
+		Short:   "Attach to a running container.",
+		Long:    "Attach to a a process that is already running inside an existing container.",
+		Example: attach_example,
+		Run: func(cmd *cobra.Command, args []string) {
+			cmdutil.CheckErr(options.Complete(f, cmd, args))
+			cmdutil.CheckErr(options.Validate())
+			cmdutil.CheckErr(options.Run())
+		},
+	}
+	// TODO support UID
+	cmd.Flags().StringVarP(&options.ContainerName, "container", "c", "", "Container name")
+	cmd.Flags().BoolVarP(&options.Stdin, "stdin", "i", false, "Pass stdin to the container")
+	cmd.Flags().BoolVarP(&options.TTY, "tty", "t", false, "Stdin is a TTY")
+	return cmd
+}
+
+// RemoteAttach defines the interface accepted by the Attach command - provided for test stubbing
+type RemoteAttach interface {
+	Attach(req *client.Request, config *client.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error
+}
+
+// DefaultRemoteAttach is the standard implementation of attaching
+type DefaultRemoteAttach struct{}
+
+func (*DefaultRemoteAttach) Attach(req *client.Request, config *client.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
+	attach := remotecommand.NewAttach(req, config, stdin, stdout, stderr, tty)
+	return attach.Execute()
+}
+
+// AttachOptions declare the arguments accepted by the Exec command
+type AttachOptions struct {
+	Namespace     string
+	PodName       string
+	ContainerName string
+	Stdin         bool
+	TTY           bool
+
+	In  io.Reader
+	Out io.Writer
+	Err io.Writer
+
+	Attach RemoteAttach
+	Client *client.Client
+	Config *client.Config
+}
+
+// Complete verifies command line arguments and loads data from the command environment
+func (p *AttachOptions) Complete(f *cmdutil.Factory, cmd *cobra.Command, argsIn []string) error {
+	if len(argsIn) == 0 {
+		return cmdutil.UsageError(cmd, "POD is required for attach")
+	}
+	if len(argsIn) > 1 {
+		return cmdutil.UsageError(cmd, fmt.Sprintf("expected a single argument: POD, saw %d: %s", len(argsIn), argsIn))
+	}
+	p.PodName = argsIn[0]
+
+	namespace, _, err := f.DefaultNamespace()
+	if err != nil {
+		return err
+	}
+	p.Namespace = namespace
+
+	config, err := f.ClientConfig()
+	if err != nil {
+		return err
+	}
+	p.Config = config
+
+	client, err := f.Client()
+	if err != nil {
+		return err
+	}
+	p.Client = client
+
+	return nil
+}
+
+// Validate checks that the provided attach options are specified.
+func (p *AttachOptions) Validate() error {
+	if len(p.PodName) == 0 {
+		return fmt.Errorf("pod name must be specified")
+	}
+	if p.Out == nil || p.Err == nil {
+		return fmt.Errorf("both output and error output must be provided")
+	}
+	if p.Attach == nil || p.Client == nil || p.Config == nil {
+		return fmt.Errorf("client, client config, and attach must be provided")
+	}
+	return nil
+}
+
+// Run executes a validated remote execution against a pod.
+func (p *AttachOptions) Run() error {
+	pod, err := p.Client.Pods(p.Namespace).Get(p.PodName)
+	if err != nil {
+		return err
+	}
+
+	if pod.Status.Phase != api.PodRunning {
+		return fmt.Errorf("pod %s is not running and cannot be attached to; current phase is %s", p.PodName, pod.Status.Phase)
+	}
+
+	containerName := p.ContainerName
+	if len(containerName) == 0 {
+		glog.V(4).Infof("defaulting container name to %s", pod.Spec.Containers[0].Name)
+		containerName = pod.Spec.Containers[0].Name
+	}
+
+	// TODO: refactor with terminal helpers from the edit utility once that is merged
+	var stdin io.Reader
+	tty := p.TTY
+	if p.Stdin {
+		stdin = p.In
+		if tty {
+			if file, ok := stdin.(*os.File); ok {
+				inFd := file.Fd()
+				if term.IsTerminal(inFd) {
+					oldState, err := term.SetRawTerminal(inFd)
+					if err != nil {
+						glog.Fatal(err)
+					}
+					// this handles a clean exit, where the command finished
+					defer term.RestoreTerminal(inFd, oldState)
+
+					// SIGINT is handled by term.SetRawTerminal (it runs a goroutine that listens
+					// for SIGINT and restores the terminal before exiting)
+
+					// this handles SIGTERM
+					sigChan := make(chan os.Signal, 1)
+					signal.Notify(sigChan, syscall.SIGTERM)
+					go func() {
+						<-sigChan
+						term.RestoreTerminal(inFd, oldState)
+						os.Exit(0)
+					}()
+				} else {
+					fmt.Fprintln(p.Err, "STDIN is not a terminal")
+				}
+			} else {
+				tty = false
+				fmt.Fprintln(p.Err, "Unable to use a TTY - input is not the right kind of file")
+			}
+		}
+	}
+
+	// TODO: consider abstracting into a client invocation or client helper
+	req := p.Client.RESTClient.Post().
+		Resource("pods").
+		Name(pod.Name).
+		Namespace(pod.Namespace).
+		SubResource("attach").
+		Param("container", containerName)
+
+	return p.Attach.Attach(req, p.Config, stdin, p.Out, p.Err, tty)
+}

pkg/kubectl/cmd/attach_test.go

+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"testing"
+
+	"github.com/spf13/cobra"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/testapi"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+)
+
+type fakeRemoteAttach struct {
+	req       *client.Request
+	attachErr error
+}
+
+func (f *fakeRemoteAttach) Attach(req *client.Request, config *client.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
+	f.req = req
+	return f.attachErr
+}
+
+func TestPodAndContainerAttach(t *testing.T) {
+	tests := []struct {
+		args              []string
+		p                 *AttachOptions
+		name              string
+		expectError       bool
+		expectedPod       string
+		expectedContainer string
+	}{
+		{
+			p:           &AttachOptions{},
+			expectError: true,
+			name:        "empty",
+		},
+		{
+			p:           &AttachOptions{},
+			args:        []string{"foo", "bar"},
+			expectError: true,
+			name:        "too many args",
+		},
+		{
+			p:           &AttachOptions{},
+			args:        []string{"foo"},
+			expectedPod: "foo",
+			name:        "no container, no flags",
+		},
+		{
+			p:                 &AttachOptions{ContainerName: "bar"},
+			args:              []string{"foo"},
+			expectedPod:       "foo",
+			expectedContainer: "bar",
+			name:              "container in flag",
+		},
+	}
+	for _, test := range tests {
+		f, tf, codec := NewAPIFactory()
+		tf.Client = &client.FakeRESTClient{
+			Codec:  codec,
+			Client: client.HTTPClientFunc(func(req *http.Request) (*http.Response, error) { return nil, nil }),
+		}
+		tf.Namespace = "test"
+		tf.ClientConfig = &client.Config{}
+
+		cmd := &cobra.Command{}
+		options := test.p
+		err := options.Complete(f, cmd, test.args)
+		if test.expectError && err == nil {
+			t.Errorf("unexpected non-error (%s)", test.name)
+		}
+		if !test.expectError && err != nil {
+			t.Errorf("unexpected error: %v (%s)", err, test.name)
+		}
+		if err != nil {
+			continue
+		}
+		if options.PodName != test.expectedPod {
+			t.Errorf("expected: %s, got: %s (%s)", test.expectedPod, options.PodName, test.name)
+		}
+		if options.ContainerName != test.expectedContainer {
+			t.Errorf("expected: %s, got: %s (%s)", test.expectedContainer, options.ContainerName, test.name)
+		}
+	}
+}
+
+func TestAttach(t *testing.T) {
+	version := testapi.Version()
+	tests := []struct {
+		name, version, podPath, attachPath, container string
+		pod                                           *api.Pod
+		attachErr                                     bool
+	}{
+		{
+			name:       "pod attach",
+			version:    version,
+			podPath:    "/api/" + version + "/namespaces/test/pods/foo",
+			attachPath: "/api/" + version + "/namespaces/test/pods/foo/attach",
+			pod:        attachPod(),
+		},
+		{
+			name:       "pod attach error",
+			version:    version,
+			podPath:    "/api/" + version + "/namespaces/test/pods/foo",
+			attachPath: "/api/" + version + "/namespaces/test/pods/foo/attach",
+			pod:        attachPod(),
+			attachErr:  true,
+		},
+	}
+	for _, test := range tests {
+		f, tf, codec := NewAPIFactory()
+		tf.Client = &client.FakeRESTClient{
+			Codec: codec,
+			Client: client.HTTPClientFunc(func(req *http.Request) (*http.Response, error) {
+				switch p, m := req.URL.Path, req.Method; {
+				case p == test.podPath && m == "GET":
+					body := objBody(codec, test.pod)
+					return &http.Response{StatusCode: 200, Body: body}, nil
+				default:
+					// Ensures no GET is performed when deleting by name
+					t.Errorf("%s: unexpected request: %s %#v\n%#v", test.name, req.Method, req.URL, req)
+					return nil, fmt.Errorf("unexpected request")
+				}
+			}),
+		}
+		tf.Namespace = "test"
+		tf.ClientConfig = &client.Config{Version: test.version}
+		bufOut := bytes.NewBuffer([]byte{})
+		bufErr := bytes.NewBuffer([]byte{})
+		bufIn := bytes.NewBuffer([]byte{})
+		ex := &fakeRemoteAttach{}
+		if test.attachErr {
+			ex.attachErr = fmt.Errorf("attach error")
+		}
+		params := &AttachOptions{
+			ContainerName: "bar",
+			In:            bufIn,
+			Out:           bufOut,
+			Err:           bufErr,
+			Attach:        ex,
+		}
+		cmd := &cobra.Command{}
+		if err := params.Complete(f, cmd, []string{"foo"}); err != nil {
+			t.Fatal(err)
+		}
+		err := params.Run()
+		if test.attachErr && err != ex.attachErr {
+			t.Errorf("%s: Unexpected exec error: %v", test.name, err)
+			continue
+		}
+		if !test.attachErr && err != nil {
+			t.Errorf("%s: Unexpected error: %v", test.name, err)
+			continue
+		}
+		if !test.attachErr && ex.req.URL().Path != test.attachPath {
+			t.Errorf("%s: Did not get expected path for exec request", test.name)
+			continue
+		}
+	}
+}
+
+func attachPod() *api.Pod {
+	return &api.Pod{
+		ObjectMeta: api.ObjectMeta{Name: "foo", Namespace: "test", ResourceVersion: "10"},
+		Spec: api.PodSpec{
+			RestartPolicy: api.RestartPolicyAlways,
+			DNSPolicy:     api.DNSClusterFirst,
+			Containers: []api.Container{
+				{
+					Name: "bar",
+				},
+			},
+		},
+		Status: api.PodStatus{
+			Phase: api.PodRunning,
+		},
+	}
+}

pkg/kubectl/cmd/cmd.go

@@ -135,6 +135,7 @@ Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`,
 	cmds.AddCommand(NewCmdRollingUpdate(f, out))
 	cmds.AddCommand(NewCmdScale(f, out))
 
+	cmds.AddCommand(NewCmdAttach(f, in, out, err))
 	cmds.AddCommand(NewCmdExec(f, in, out, err))
 	cmds.AddCommand(NewCmdPortForward(f))
 	cmds.AddCommand(NewCmdProxy(f, out))