Move power to cmd

cmd/power/power.go

@@ -0,0 +1,148 @@
+package power
+
+import (
+	"bufio"
+	"errors"
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"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, "/")
+
+	for 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
+}