add power functions - down, restart, halt

config/config.go

@@ -78,11 +78,11 @@ func NewConfig() *Config {
 			"8.8.8.8",
 			"8.8.4.4",
 		},
-		ImagesPath:    "/",
-		ImagesPattern: "images*.tar",
-		StateRequired: false,
+		ImagesPath:       "/",
+		ImagesPattern:    "images*.tar",
+		StateRequired:    false,
 		StateDev:         "LABEL=RANCHER_STATE",
-		StateDevFSType:   "auto",
+		StateDevFSType:   "ext4",
 		SysInit:          "/sbin/init-sys",
 		SystemDockerArgs: []string{"docker", "-d", "-s", "overlay", "-b", "none"},
 		UserInit:         "/sbin/init-user",
@@ -143,6 +143,9 @@ func NewConfig() *Config {
 					"--volume", "/init:/usr/bin/system-docker:ro",
 					"--volume", "/init:/usr/bin/respawn:ro",
 					"--volume", "/var/run/docker.sock:/var/run/system-docker.sock:ro",
+					"--volume", "/sbin/poweroff:/sbin/poweroff:ro",
+					"--volume", "/sbin/reboot:/sbin/reboot:ro",
+					"--volume", "/sbin/halt:/sbin/halt:ro",
 					"--volumes-from", "system-state",
 					"--net", "host",
 					"--pid", "host",

init/init.go

@@ -55,6 +55,9 @@ var (
 		"/sbin/modprobe":                     "/busybox",
 		"/var/run":                           "/run",
 		DOCKER:                               "/docker",
+		"/sbin/poweroff":                     "/init",
+		"/sbin/halt":                         "/init",
+		"/sbin/reboot":                       "/init",
 	}
 )
 
@@ -215,10 +218,10 @@ func mountState(cfg *config.Config) error {
 	var err error
 
 	dev := util.ResolveDevice(cfg.StateDev)
-	log.Debugf("Mounting state device %s", dev)	
+	log.Debugf("Mounting state device %s", dev)
 
 	fsType := cfg.StateDevFSType
-	log.Debugf("FsType has been set to %s", fsType)	
+	log.Debugf("FsType has been set to %s", fsType)
 	if fsType == "auto" {
 		actualFsType, fsErr := util.GetFsType(dev)
 		if fsErr != nil {

main.go

@@ -6,6 +6,7 @@ import (
 	log "github.com/Sirupsen/logrus"
 	"github.com/docker/docker/pkg/reexec"
 	osInit "github.com/rancherio/os/init"
+	"github.com/rancherio/os/power"
 	"github.com/rancherio/os/respawn"
 	"github.com/rancherio/os/sysinit"
 	"github.com/rancherio/os/user"
@@ -18,8 +19,10 @@ func main() {
 	reexec.Register("/sbin/init-sys", sysinit.SysInit)
 	reexec.Register("/usr/bin/system-docker", user.SystemDocker)
 	reexec.Register("system-docker", user.SystemDocker)
+	reexec.Register("poweroff", power.PowerOff)
+	reexec.Register("reboot", power.Reboot)
+	reexec.Register("halt", power.Halt)
 	reexec.Register("respawn", respawn.Main)
-
 	if !reexec.Init() {
 		log.Fatalf("Failed to find an entry point for %s", os.Args[0])
 	}

power/power.go

@@ -0,0 +1,151 @@
+package power
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"strconv"
+	"syscall"
+	"strings"
+
+	"github.com/fsouza/go-dockerclient"
+)
+
+
+const (
+	dockerPath = "unix:///var/run/system-docker.sock"
+	dockerCGroupsFile = "/proc/self/cgroup"
+)
+
+func PowerOff() {
+	reboot(syscall.LINUX_REBOOT_CMD_POWER_OFF)
+}
+
+func Reboot() {
+	reboot(syscall.LINUX_REBOOT_CMD_RESTART)
+}
+
+func Halt() {
+	reboot(syscall.LINUX_REBOOT_CMD_HALT)
+}
+
+func reboot(code int) {
+	err := shutDownContainers()
+	if err != nil {
+		panic(err)
+	}
+	err = syscall.Reboot(code)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func shutDownContainers() error {
+	var err error
+	shutDown := true
+	timeout := uint(0)
+	for i := range os.Args {
+		arg := os.Args[i]
+		if arg == "-f" || arg == "--f" || arg == "--force" {
+			shutDown = false
+		}
+		if arg == "-t" || arg == "--t" || arg == "--timeout" {
+			if len(os.Args) > i+1 {
+				t, er := strconv.Atoi(os.Args[i+1])
+				if er != nil {
+					return err
+				}
+				timeout = uint(t)
+			} else {
+				panic("please specify a timeout")
+			}
+		}
+	}
+	if !shutDown {
+		return nil
+	}
+	client, err := docker.NewClient(dockerPath)
+	
+	if err != nil {
+		return err
+	}
+
+	opts := docker.ListContainersOptions{All: true, Filters: map[string][]string{"status": []string{"running"}}}
+	var containers []docker.APIContainers
+	
+	containers, err = client.ListContainers(opts)
+
+	if err != nil {
+		return err
+	}
+
+	currentContainerId, err := getCurrentContainerId()
+
+	if err != nil {
+		return err
+	}
+
+	var stopErrorStrings []string
+
+	for i := range containers {
+		if containers[i].ID == currentContainerId {
+			continue
+		}
+		stopErr := client.StopContainer(containers[i].ID, timeout)
+		if stopErr != nil {
+			stopErrorStrings = append(stopErrorStrings, " [" + containers[i].ID  + "] " +stopErr.Error())
+		}
+	}
+
+	var waitErrorStrings []string
+
+	for i := range containers {
+		if containers[i].ID == currentContainerId {
+			continue
+		}
+		_, waitErr := client.WaitContainer(containers[i].ID)
+		if waitErr != nil {
+			 waitErrorStrings = append(waitErrorStrings, " [" + containers[i].ID  + "] " + waitErr.Error())
+		}
+	}
+		
+	if len(waitErrorStrings) != 0 || len(stopErrorStrings) != 0 {
+		return errors.New("error while stopping \n1. STOP Errors [" + strings.Join(stopErrorStrings, ",") + "] \n2. WAIT Errors [" + strings.Join(waitErrorStrings, ",") + "]")
+	}
+
+	return nil
+}
+
+
+func getCurrentContainerId() (string, error) {
+	file, err := os.Open(dockerCGroupsFile)
+
+	if err != nil {
+		return "", err
+	}
+
+	fileReader := bufio.NewScanner(file)
+	if !fileReader.Scan() {
+		return "", errors.New("Empty file /proc/self/cgroup")
+	}
+	line := fileReader.Text()
+	parts := strings.Split(line, "/")
+
+	while len(parts) != 3 {
+		if !fileReader.Scan() {
+			return "", errors.New("Found no docker cgroups")
+		}
+		line = fileReader.Text()
+		parts = strings.Split(line, "/")
+		if len(parts) == 3 {
+			if strings.HasSuffix(parts[1], "docker") {
+				break
+			} else {
+				parts = nil
+			}
+		}
+	}
+
+	return parts[len(parts)-1:][0], nil
+}
+