add upgrade framework for rancherctl os command

cmd/control/cli.go

@@ -45,20 +45,7 @@ func Main() {
 		{
 			Name:  "os",
 			Usage: "operating system upgrade/downgrade",
-			Subcommands: []cli.Command{
-				{
-					Name:  "list",
-					Usage: "list available RancherOS versions and state",
-				},
-				{
-					Name:  "update",
-					Usage: "download the latest new version of RancherOS",
-				},
-				{
-					Name:  "activate",
-					Usage: "switch to a new version of RancherOS and reboot",
-				},
-			},
+			Subcommands: osSubcommands(),
 		},
 	}
 

cmd/control/config.go

@@ -186,7 +186,7 @@ func getOrSetVal(args string, data map[interface{}]interface{}, value interface{
 	for i, part := range parts {
 		val, ok := data[part]
 		last := i+1 == len(parts)
-
+	
 		if last && value != nil {
 			if s, ok := value.(string); ok {
 				value = config.DummyMarshall(s)

cmd/control/os.go

@@ -0,0 +1,197 @@
+package control
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+
+	log "github.com/Sirupsen/logrus"
+
+	"github.com/codegangsta/cli"
+	"github.com/rancherio/os/cmd/power"
+	"github.com/rancherio/os/config"
+	"github.com/rancherio/os/docker"
+)
+
+var osChannels map[string]string
+
+const (
+	osVersionsFile = "/var/lib/rancher/versions"
+)
+
+func osSubcommands() []cli.Command {
+	return []cli.Command{
+		{
+			Name:   "upgrade",
+			Usage:  "upgrade to latest version",
+			Action: osUpgrade,
+			Flags: []cli.Flag{
+				cli.BoolFlag{
+					Name: "stage, s",
+					Usage: "Only stage the new upgrade, don't apply it",
+				},
+				cli.StringFlag{
+					Name: "image, i",
+					Usage: "upgrade to a certain image",
+				},
+				cli.StringFlag{
+					Name: "channel, c",
+					Usage: "upgrade to the latest in a specific channel",
+				},
+			},
+		},
+		{
+			Name: "list",
+			Usage: "list the current available versions",
+			Action: osMetaDataGet,
+		},
+		{
+			Name: "rollback",
+			Usage: "rollback to the previous version",
+			Action: osRollback,
+		},
+	}
+}
+
+func osRollback(c *cli.Context) {
+	file, err := os.Open(osVersionsFile)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fileReader := bufio.NewScanner(file)
+	line := " "
+	for ; line[len(line)-1:] != "*"; {
+		if !fileReader.Scan() {
+			log.Error("Current version not indicated in "+ osVersionsFile)
+		}
+		line = fileReader.Text()
+	}
+	if !fileReader.Scan() {
+		log.Error("already at earliest version, please choose a version specifically using upgrade --image")
+	}
+	line = fileReader.Text()
+	//TODO: process string if required
+
+	startUpgradeContainer(line, false)
+}
+	
+func osMetaDataGet(c *cli.Context) {
+	osChannel, ok := getChannelUrl("meta"); if !ok {
+		log.Fatal("unrecognized channel meta")
+	}
+	resp, err := http.Get(osChannel)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Print(parseBody(body, osChannel))
+}
+
+func osUpgrade(c *cli.Context) {
+	channel := c.String("channel")
+
+	image := c.String("image")
+
+	if image == "" {
+		var err error
+		image, err = getLatestImage(channel)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+	startUpgradeContainer(image, c.Bool("stage"))
+}
+
+func startUpgradeContainer(image string, stage bool) {
+	container := docker.NewContainer(config.DOCKER_SYSTEM_HOST, &config.ContainerConfig{
+		Cmd:  "--name=upgrade " +
+			"--privileged " +
+			"--net=host " +
+			"--ipc=host " +
+			"--pid=host " +
+			"-v=/var:/var " +
+			"--volumes-from=system-volumes " +
+			image,
+	}).Stage()
+
+	if container.Err != nil {
+		log.Fatal(container.Err)
+	}
+
+	if !stage {
+		container.StartAndWait()
+		if container.Err != nil {
+			log.Fatal(container.Err)
+		}
+		power.Reboot()
+	}
+}
+
+func getLatestImage(channel string) (string, error) {
+	data, err := getConfigData()
+
+	if err != nil {
+		return "", err	
+	}
+
+	var pivot string
+
+	if pivot == "" {
+		val := getOrSetVal("os_upgrade_channel", data, nil)
+
+		if val == nil {
+			return "", errors.New("os_upgrade_channel is not set")
+		}
+
+		switch currentChannel := val.(type) {
+			case string:
+				pivot = currentChannel
+			default:
+				return "", errors.New("invalid format of rancherctl config get os_upgrade_channel")
+		}
+	} else {
+		pivot = channel
+	}
+	osChannel, ok := getChannelUrl(pivot); if !ok {
+		return "", errors.New("unrecognized channel " + pivot)
+	}
+	resp, err := http.Get(osChannel)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	return parseBody(body, osChannel), nil
+}
+
+func parseBody(body []byte, channel string) string {
+	// just going to assume that the response is the image name
+	// can change it later based on server response design
+	return string(body)
+}
+
+func getChannelUrl(channel string) (string, bool) {
+	if osChannels == nil {
+		osChannels = map[string]string {
+				"stable" : "",
+				"alpha" : "",
+				"beta" : "",
+				"meta" : "",
+		}
+	}
+	channel, ok := osChannels[channel]; 
+	return channel, ok
+}
+

config/config.go

@@ -46,6 +46,7 @@ type Config struct {
 	RescueContainer  *ContainerConfig  `yaml:"rescue_container,omitempty"`
 	State            ConfigState       `yaml:"state,omitempty"`
 	Userdocker       UserDockerInfo    `yaml:"userdocker,omitempty"`
+	OsUpgradeChannel string		   `yaml:"os_upgrade_channel,omitempty"`
 	SystemContainers []ContainerConfig `yaml:"system_containers,omitempty"`
 	SystemDockerArgs []string          `yaml:"system_docker_args,flow,omitempty"`
 	Modules          []string          `yaml:"modules,omitempty"`