Add kpod wait

Waits on one or more containers to stop and prints the container's
return code

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

.travis.yml

@@ -8,7 +8,7 @@ services:
 before_install:
   - sudo apt-get -qq update
   - sudo apt-get -qq install btrfs-tools libdevmapper-dev libgpgme11-dev libapparmor-dev libseccomp-dev
-  - sudo apt-get -qq install autoconf automake bison e2fslibs-dev libfuse-dev libtool liblzma-dev
+  - sudo apt-get -qq install autoconf automake bison e2fslibs-dev libfuse-dev libtool liblzma-dev gettext
 
 install:
   - make install.tools

Dockerfile

@@ -12,6 +12,7 @@ RUN apt-get update && apt-get install -y \
     curl \
     e2fslibs-dev \
     gawk \
+    gettext \
     iptables \
     pkg-config \
     libaio-dev \

README.md

@@ -65,6 +65,7 @@ It is currently in active development in the Kubernetes community through the [d
 | [kpod-umount(1)](/docs/kpod-umount.1.md)             | Unmount a working container's root filesystem                             ||
 | [kpod-unpause(1)](/docs/kpod-unpause.1.md)           | Unpause one or more running containers                                    ||
 | [kpod-version(1)](/docs/kpod-version.1.md)           | Display the version information                                           |[![...](/docs/play.png)](https://asciinema.org/a/mfrn61pjZT9Fc8L4NbfdSqfgu)|
+| [kpod-wait(1)](/docs/kpod-wait.1.md)                 | Wait on one or more containers to stop and print their exit codes||
 
 ## Configuration
 | File                                       | Description                                                                                          |

cmd/kpod/main.go

@@ -54,6 +54,7 @@ func main() {
 		umountCommand,
 		unpauseCommand,
 		versionCommand,
+		waitCommand,
 	}
 	app.Before = func(c *cli.Context) error {
 		logrus.SetLevel(logrus.ErrorLevel)

cmd/kpod/wait.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/kubernetes-incubator/cri-o/libkpod"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+var (
+	waitDescription = `
+	kpod wait
+
+	Block until one or more containers stop and then print their exit codes
+`
+
+	waitCommand = cli.Command{
+		Name:        "wait",
+		Usage:       "Block on one or more containers",
+		Description: waitDescription,
+		Action:      waitCmd,
+		ArgsUsage:   "CONTAINER-NAME [CONTAINER-NAME ...]",
+	}
+)
+
+func waitCmd(c *cli.Context) error {
+	args := c.Args()
+	if len(args) < 1 {
+		return errors.Errorf("you must provide at least one container name or id")
+	}
+
+	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")
+	}
+
+	var lastError error
+	for _, container := range c.Args() {
+		returnCode, err := server.ContainerWait(container)
+		if err != nil {
+			if lastError != nil {
+				fmt.Fprintln(os.Stderr, lastError)
+			}
+			lastError = errors.Wrapf(err, "failed to wait for the container %v", container)
+		} else {
+			fmt.Println(returnCode)
+		}
+	}
+
+	return lastError
+}

completions/bash/kpod

@@ -388,6 +388,11 @@ _kpod_unpause() {
      "
      local boolean_options=""
      _complete_ "$options_with_args" "$boolean_options"
+
+_kpod_wait() {
+     local options_with_args=""
+     local boolean_options="--help -h"
+     _complete_ "$options_with_args" "$boolean_options"
 }
 
 _complete_() {
@@ -455,6 +460,7 @@ _kpod_kpod() {
     unmount
     unpause
     version
+    wait
      "
 
      case "$prev" in

docs/kpod-wait.1.md

@@ -0,0 +1,36 @@
+% kpod(1) kpod-wait - Waits on a container
+% Brent Baude
+# kpod-wait "1" "September 2017" "kpod"
+
+## NAME
+kpod wait - Waits on one or more containers to stop and prints exit code
+
+## SYNOPSIS
+**kpod wait**
+[**--help**|**-h**]
+
+## DESCRIPTION
+Waits on one or more containers to stop.  The container can be referred to by its
+name or ID.  In the case of multiple containers, kpod will wait on each consecutively.
+After the container stops, the container's return code is printed.
+
+**kpod [GLOBAL OPTIONS] wait **
+
+## GLOBAL OPTIONS
+
+**--help, -h**
+  Print usage statement
+
+## EXAMPLES
+
+  kpod wait mywebserver
+
+  kpod wait 860a4b23
+
+  kpod wait mywebserver myftpserver
+
+## SEE ALSO
+kpod(1), crio(8), crio.conf(5)
+
+## HISTORY
+September 2017, Originally compiled by Brent Baude<bbaude@redhat.com>

libkpod/wait.go

@@ -0,0 +1,42 @@
+package libkpod
+
+import (
+	"github.com/kubernetes-incubator/cri-o/oci"
+	"github.com/pkg/errors"
+	"k8s.io/apimachinery/pkg/util/wait"
+)
+
+func isStopped(c *ContainerServer, ctr *oci.Container) bool {
+	c.runtime.UpdateStatus(ctr)
+	cStatus := c.runtime.ContainerStatus(ctr)
+	if cStatus.Status == oci.ContainerStateStopped {
+		return true
+	}
+	return false
+}
+
+// ContainerWait stops a running container with a grace period (i.e., timeout).
+func (c *ContainerServer) ContainerWait(container string) (int32, error) {
+	ctr, err := c.LookupContainer(container)
+	if err != nil {
+		return 0, errors.Wrapf(err, "failed to find container %s", container)
+	}
+
+	err = wait.PollImmediateInfinite(1,
+		func() (bool, error) {
+			if !isStopped(c, ctr) {
+				return false, nil
+			} else { // nolint
+				return true, nil // nolint
+			} // nolint
+
+		},
+	)
+
+	if err != nil {
+		return 0, err
+	}
+	exitCode := ctr.State().ExitCode
+	c.ContainerStateToDisk(ctr)
+	return exitCode, nil
+}

test/kpod_wait.bats

@@ -0,0 +1,70 @@
+#!/usr/bin/env bats
+
+load helpers
+
+IMAGE="redis:alpine"
+ROOT="$TESTDIR/crio"
+RUNROOT="$TESTDIR/crio-run"
+KPOD_OPTIONS="--root $ROOT --runroot $RUNROOT ${STORAGE_OPTS}"
+
+
+# Returns the POD ID
+function pod_run_from_template(){
+    #1=name, 2=uid, 3=namespace) {
+    NAME=$1 CUID=$2 NAMESPACE=$3 envsubst < ${TESTDATA}/template_sandbox_config.json > ${TESTDIR}/pod-${1}.json
+    crioctl pod run --config ${TESTDIR}/pod-${1}.json
+}
+
+# Returns the container ID
+function container_create_from_template() {
+    #1=name, 2=image, 3=command, 4=id) {
+    NAME=$1 IMAGE=$2 COMMAND=$3 envsubst < ${TESTDATA}/template_container_config.json > ${TESTDIR}/ctr-${1}.json
+    crioctl ctr create --config ${TESTDIR}/ctr-${1}.json --pod "$4"
+}
+
+function container_start() {
+    #1=id
+    crioctl ctr start --id "$1"
+
+}
+@test "wait on a bogus container" {
+    start_crio
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} wait 12343
+    echo $output
+    [ "$status" -eq 1 ]
+    stop_crio
+}
+
+@test "wait on a stopped container" {
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} pull docker.io/library/busybox:latest
+    echo $output
+    start_crio
+    pod_id=$( pod_run_from_template "test" "test" "test1-1" )
+    echo $pod_id
+    ctr_id=$(container_create_from_template "test-CTR" "docker.io/library/busybox:latest" '["ls"]' "${pod_id}")
+    echo $ctr_id
+    container_start $ctr_id
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} wait $ctr_id
+    [ "$status" -eq 0 ]
+    cleanup_ctrs
+    cleanup_pods
+    stop_crio
+}
+
+@test "wait on a sleeping container" {
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} pull docker.io/library/busybox:latest
+    echo $output
+    start_crio
+    pod_id=$( pod_run_from_template "test" "test" "test1-1" )
+    echo $pod_id
+    ctr_id=$(container_create_from_template "test-CTR" "docker.io/library/busybox:latest" '["sleep", "5"]' "${pod_id}")
+    echo $ctr_id
+    run container_start $ctr_id
+    echo $output
+    run ${KPOD_BINARY} ${KPOD_OPTIONS} wait $ctr_id
+    echo $output
+    [ "$status" -eq 0 ]
+    cleanup_ctrs
+    cleanup_pods
+    stop_crio
+}

test/testdata/template_container_config.json

@@ -0,0 +1,68 @@
+{
+	"metadata": {
+		"name": "${NAME}",
+		"attempt": 1
+	},
+	"image": {
+		"image": "${IMAGE}"
+	},
+	"command": ${COMMAND},
+	"args": [],
+	"working_dir": "/",
+	"envs": [
+		{
+			"key": "PATH",
+			"value": "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+		},
+		{
+			"key": "TERM",
+			"value": "xterm"
+		},
+		{
+			"key": "TESTDIR",
+			"value": "test/dir1"
+		},
+		{
+			"key": "TESTFILE",
+			"value": "test/file1"
+		}
+	],
+	"labels": {
+		"type": "small",
+		"batch": "no"
+	},
+	"annotations": {
+		"owner": "dragon",
+		"daemon": "crio"
+	},
+	"privileged": true,
+	"log_path": "",
+	"stdin": false,
+	"stdin_once": false,
+	"tty": false,
+	"linux": {
+		"resources": {
+			"cpu_period": 10000,
+			"cpu_quota": 20000,
+			"cpu_shares": 512,
+			"oom_score_adj": 30
+		},
+		"security_context": {
+			"readonly_rootfs": false,
+			"selinux_options": {
+				"user": "system_u",
+				"role": "system_r",
+				"type": "svirt_lxc_net_t",
+				"level": "s0:c4,c5"
+			},
+			"capabilities": {
+				"add_capabilities": [
+					"setuid",
+					"setgid"
+				],
+				"drop_capabilities": [
+				]
+			}
+		}
+	}
+}

test/testdata/template_sandbox_config.json

@@ -0,0 +1,51 @@
+{
+	"metadata": {
+		"name": "${NAME}",
+		"uid": "${CUID}",
+		"namespace": "${NAMESPACE}",
+		"attempt": 1
+	},
+	"hostname": "crioctl_host",
+	"log_directory": "",
+	"dns_config": {
+		"searches": [
+			"8.8.8.8"
+		]
+	},
+	"port_mappings": [],
+	"resources": {
+		"cpu": {
+			"limits": 3,
+			"requests": 2
+		},
+		"memory": {
+			"limits": 50000000,
+			"requests": 2000000
+		}
+	},
+	"labels": {
+		"group": "test"
+	},
+	"annotations": {
+		"owner": "hmeng",
+		"security.alpha.kubernetes.io/sysctls": "kernel.shm_rmid_forced=1,net.ipv4.ip_local_port_range=1024 65000",
+		"security.alpha.kubernetes.io/unsafe-sysctls": "kernel.msgmax=8192" ,
+		"security.alpha.kubernetes.io/seccomp/pod": "unconfined"
+	},
+	"linux": {
+		"cgroup_parent": "/Burstable/pod_123-456",
+		"security_context": {
+			"namespace_options": {
+				"host_network": false,
+				"host_pid": false,
+				"host_ipc": false
+			},
+			"selinux_options": {
+				"user": "system_u",
+				"role": "system_r",
+				"type": "svirt_lxc_net_t",
+				"level": "s0:c4,c5"
+			}
+		}
+	}
+}

transfer.md

@@ -58,5 +58,6 @@ There are other equivalents for these tools
 | `docker stop`   | [`kpod stop`](./docs/kpod-stop.1.md)      |
 | `docker unpause`| [`kpod unpause`](./docs/kpod-unpause.1.md)|
 | `docker version`| [`kpod version`](./docs/kpod-version.1.md)|
+| `docker wait`   | [`kpod wait`](./docs/kpod-wait.1.md)|
 
 *** Use mount to take advantage of the entire linux tool chain rather then just cp.  Read [`here`](./docs/kpod-cp.1.md) for more information.