Add kpod attach

Run a command in a running container

Signed-off-by: baude <bbaude@redhat.com>

README.md

@@ -43,6 +43,7 @@ It is currently in active development in the Kubernetes community through the [d
 | [kpod(1)](/docs/kpod.1.md)                           | Simple management tool for pods and images                                ||
 | [kpod-cp(1)](/docs/kpod-cp.1.md)                     | Instead of providing a `kpod cp` command, the man page `kpod-cp` describes how to use the `kpod mount` command to have even more flexibility and functionality.||
 | [kpod-diff(1)](/docs/kpod-diff.1.md)                 | Inspect changes on a container or image's filesystem                      ||
+| [kpod-exec(1)](/docs/kpod-exec.1.md)                 | Execute a command in a running container
 | [kpod-export(1)](/docs/kpod-export.1.md)             | Export container's filesystem contents as a tar archive                   ||
 | [kpod-history(1)](/docs/kpod-history.1.md)           | Shows the history of an image                                             |[![...](/docs/play.png)](https://asciinema.org/a/bCvUQJ6DkxInMELZdc5DinNSx)|
 | [kpod-images(1)](/docs/kpod-images.1.md)             | List images in local storage                                              |[![...](/docs/play.png)](https://asciinema.org/a/133649)|

cmd/kpod/exec.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"github.com/kubernetes-incubator/cri-o/libkpod"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+var (
+	execFlags = []cli.Flag{
+		cli.BoolFlag{
+			Name:  "detach, d",
+			Usage: "detached mode: command will run in the background",
+		},
+		cli.StringSliceFlag{
+			Name:  "env, e",
+			Usage: "set environment variables",
+		},
+		cli.BoolFlag{
+			Name:  "tty, t",
+			Usage: "Allocate a pseudo TTY",
+		},
+		cli.StringFlag{
+			Name:  "user, u",
+			Usage: "Sets the username (UID) and groupname (GID) for the specified command",
+		},
+	}
+	execDescription = `
+   kpod exec
+
+   Run a command in a running container.  The command will only run while the primary
+	PID in the container is running.
+`
+
+	execCommand = cli.Command{
+		Name:        "exec",
+		Usage:       "Run a command in a running container",
+		Description: execDescription,
+		Flags:       execFlags,
+		Action:      execCmd,
+		ArgsUsage:   "[OPTIONS} CONTAINER-NAME COMMAND",
+	}
+)
+
+func execCmd(c *cli.Context) error {
+	args := c.Args()
+	detachFlag := c.Bool("detach")
+	envFlags := c.StringSlice("env")
+	ttyFlag := c.Bool("tty")
+	userFlag := c.String("user")
+
+	if len(args) < 2 {
+		return errors.Errorf("you must provide a container name or ID and a command to run")
+	}
+	if err := validateFlags(c, execFlags); err != nil {
+		return err
+	}
+	container := args[0]
+	var command []string
+	for _, cmd := range args[1:] {
+		command = append(command, cmd)
+	}
+
+	config, err := getConfig(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get config")
+	}
+	server, err := libkpod.New(config)
+	if err != nil {
+		return errors.Wrapf(err, "could not get container server")
+	}
+	defer server.Shutdown()
+	err = server.Update()
+	if err != nil {
+		return errors.Wrapf(err, "could not update list of containers")
+	}
+	if err := server.ContainerExec(container, command, detachFlag, envFlags, ttyFlag, userFlag); err != nil {
+		return err
+	}
+	return nil
+
+}

cmd/kpod/main.go

@@ -32,6 +32,7 @@ func main() {
 
 	app.Commands = []cli.Command{
 		diffCommand,
+		execCommand,
 		exportCommand,
 		historyCommand,
 		imagesCommand,

completions/bash/kpod

@@ -404,6 +404,12 @@ _kpod_wait() {
      _complete_ "$options_with_args" "$boolean_options"
 }
 
+_kpod_exec() {
+     local options_with_args="--env -e --user -u"
+     local boolean_options="--help -h --tty -t --detach -d"
+     _complete_ "$options_with_args" "$boolean_options"
+}
+
 _complete_() {
     local options_with_args=$1
     local boolean_options="$2 -h --help"
@@ -446,6 +452,7 @@ _kpod_kpod() {
      "
      commands="
     diff
+    exec
     export
     history
     images

docs/kpod-exec.1.md

@@ -0,0 +1,48 @@
+% kpod(1) kpod-exec - Run a command in a running container
+% Brent Baude
+# kpod-exec "1" "October 2017" "kpod"
+
+## NAME
+kpod exec - Run a command in a running container
+
+## SYNOPSIS
+**kpod exec [OPTIONS] CONTAINER COMMAND
+
+## DESCRIPTION
+Run a command in a running container. The command will only run while the container's primary process (PID 1) is running.
+restarted if the container is restarted.
+
+## OPTIONS
+
+**--detach, -d**
+
+Detached mode: run the command in the background.
+
+**--env, -e**
+
+Set one or environment variables for the container environment.
+
+**--tty, -t**
+
+Allocate a pseudo-TTY.
+
+**--user, -u**
+
+Sets the username or UID used and optionally the groupname or GID for the specified command. The format is *uid:gid*.
+
+
+## EXAMPLE
+
+kpod exec mywebserver ls
+
+kpod exec 860a4b23 ls
+
+kpod exec -e FOO=bar -e BAR=foo 860a4b23 ls
+
+kpod exec -u foo:users mywebserver ls
+
+## SEE ALSO
+kpod(1)
+
+## HISTORY
+October 2017, Originally compiled by Brent Baude <bbaude@redhat.com>

docs/kpod-stop.1.md

@@ -32,4 +32,4 @@ kpod stop --timeout 2 860a4b23
 kpod(1), kpod-rm(1)
 
 ## HISTORY
-September 2018, Originally compiled by Brent Baude <bbaude@redhat.com>
+September 2017, Originally compiled by Brent Baude <bbaude@redhat.com>

libkpod/exec.go

@@ -0,0 +1,29 @@
+package libkpod
+
+import (
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/pkg/errors"
+)
+
+// ContainerExec runs a command in a running container
+func (c *ContainerServer) ContainerExec(container string, command []string, detach bool, environmentVars []string, tty bool, user string) error {
+	ctr, err := c.LookupContainer(container)
+	if err != nil {
+		return errors.Wrapf(err, "failed to find container %s", container)
+	}
+	ctrID := ctr.ID()
+
+	cStatus := c.runtime.ContainerStatus(ctr)
+	switch cStatus.Status {
+	case oci.ContainerStatePaused:
+		return errors.Errorf("cannot run a command in a paused container %s", ctrID)
+	case oci.ContainerStateRunning:
+		if err := c.runtime.ExecContainerCommand(ctr, command, detach, environmentVars, tty, user); err != nil {
+			return errors.Wrapf(err, "failed to exec command in container %s", ctrID)
+		}
+	default:
+		return errors.Errorf("container %s is not running", ctrID)
+	}
+
+	return nil
+}

oci/oci.go

@@ -716,3 +716,30 @@ func (r *Runtime) UnpauseContainer(c *Container) error {
 	_, err := utils.ExecCmd(r.Path(c), "resume", c.id)
 	return err
 }
+
+// ExecContainerCommand runs a command inside a running container
+func (r *Runtime) ExecContainerCommand(c *Container, command []string, detach bool, environmentVars []string, tty bool, user string) error {
+	//var args []string
+	commandArgs := []string{"exec"}
+	if tty {
+		commandArgs = append(commandArgs, "-t")
+	}
+	if detach {
+		commandArgs = append(commandArgs, "-d")
+	}
+	for _, envVar := range environmentVars {
+		commandArgs = append(commandArgs, "-e", envVar)
+	}
+	if user != "" {
+		commandArgs = append(commandArgs, "-u", user)
+	}
+	commandArgs = append(commandArgs, c.id)
+	commandArgs = append(commandArgs, command...)
+	logrus.Debug("Running command: %s", strings.Join(commandArgs, " "))
+	c.opLock.Lock()
+	defer c.opLock.Unlock()
+	err := utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, r.Path(c), commandArgs...)
+	return err
+	return nil
+
+}

test/kpod_exec.bats

@@ -0,0 +1,78 @@
+#!/usr/bin/env bats
+
+load helpers
+
+IMAGE="redis:alpine"
+
+function teardown() {
+    cleanup_test
+}
+
+@test "exec on a bogus container" {
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} exec foobar ls
+    echo "$output"
+    [ "$status" -eq 1 ]
+}
+
+@test "Run a simple command" {
+    start_crio
+    run crioctl pod run --config "$TESTDATA"/sandbox_config.json
+    echo "$output"
+    [ "$status" -eq 0 ]
+    pod_id="$output"
+    run crioctl image pull "$IMAGE"
+    [ "$status" -eq 0 ]
+    run crioctl ctr create --config "$TESTDATA"/container_redis.json --pod "$pod_id"
+    echo "$output"
+    [ "$status" -eq 0 ]
+    ctr_id="$output"
+    run crioctl ctr start --id "$ctr_id"
+    echo "$output"
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} exec "$ctr_id" ls
+    echo "$output"
+    [ "$status" -eq 0 ]
+    cleanup_pods
+    stop_crio
+}
+
+# Disabled until runc is fixed upstream to handle
+# longer and more complicated command sequences.
+#@test "Check for environment variable" {
+#    start_crio
+#    run crioctl pod run --config "$TESTDATA"/sandbox_config.json
+#    echo "$output"
+#    [ "$status" -eq 0 ]
+#    pod_id="$output"
+#    run crioctl image pull "$IMAGE"
+#    [ "$status" -eq 0 ]
+#    run crioctl ctr create --config "$TESTDATA"/container_redis.json --pod "$pod_id"
+#    echo "$output"
+#    [ "$status" -eq 0 ]
+#    ctr_id="$output"
+#    run crioctl ctr start --id "$ctr_id"
+#    echo "$output"
+#    run ${KPOD_BINARY} ${KPOD_OPTIONS} exec -e FOO=bar "$ctr_id" env | grep FOO
+#    echo "$output"
+#    [ "$status" -eq 0 ]
+#    cleanup_pods
+#    stop_crio
+#}
+
+@test "Execute command in a non-running container" {
+    start_crio
+    run crioctl pod run --config "$TESTDATA"/sandbox_config.json
+    echo "$output"
+    [ "$status" -eq 0 ]
+    pod_id="$output"
+    run crioctl image pull "$IMAGE"
+    [ "$status" -eq 0 ]
+    run crioctl ctr create --config "$TESTDATA"/container_config.json --pod "$pod_id"
+    echo "$output"
+    [ "$status" -eq 0 ]
+    ctr_id="$output"
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} exec ls
+    echo "$output"
+    [ "$status" -eq 1 ]
+    cleanup_pods
+    stop_crio
+}

transfer.md

@@ -24,7 +24,6 @@ Following provides equivalent with cri-o tools for gathering information or jump
 
 | Existing Step | CRI-O (and friends) |
 | :---: | :---: |
-| `docker exec` | [`crioctl ctr exec`](./docs/crio.8.md) |
 | `docker info` | [`kpod info`](./docs/kpod-info.1.md)  |
 | `docker inspect` | [`kpod inspect`](./docs/kpod-inspect.1.md)       |
 | `docker logs` | [`kpod logs`](./docs/kpod-logs.1.md)                 |
@@ -42,6 +41,7 @@ There are other equivalents for these tools
 | `docker build`  | [`buildah bud`](https://github.com/projectatomic/buildah/blob/master/docs/buildah-bud.md) |
 | `docker cp`     | [`kpod mount`](./docs/kpod-cp.1.md) ***   |
 | `docker diff`   | [`kpod diff`](./docs/kpod-diff.1.md)      |
+| `docker exec`   | [`kpod exec`](./docs/kpod-exec.1.md)      |
 | `docker export` | [`kpod export`](./docs/kpod-export.1.md)  |
 | `docker history`| [`kpod history`](./docs/kpod-history.1.md)|
 | `docker images` | [`kpod images`](./docs/kpod-images.1.md)  |