Add support for upgrading binaries

`boot2docker upgrade` will support the Docker client binary,
boot2docker-cli binary, and boot2docker ISO now.

Signed-off-by: Nathan LeClaire <nathan.leclaire@gmail.com>

Author: Nathan LeClaire

cmds.go

@@ -3,6 +3,9 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"net/http"
+
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -277,6 +280,19 @@ func cmdPoweroff() error {
 
 // Upgrade the boot2docker ISO - preserving server state
 func cmdUpgrade() error {
+	if runtime.GOOS == "darwin" || runtime.GOOS == "linux" {
+		if B2D.Clobber {
+			err := upgradeDockerClientBinary()
+			if err != nil {
+				return err
+			}
+		} else {
+			fmt.Println("Skipping client binary download, use --clobber=true to enable...")
+		}
+	}
+	if err := upgradeBoot2DockerBinary(); err != nil {
+		return fmt.Errorf("Error upgrading boot2docker binary: %s", err)
+	}
 	m, err := driver.GetMachine(&B2D)
 	if err == nil {
 		if m.GetState() == driver.Running || m.GetState() == driver.Saved || m.GetState() == driver.Paused {
@@ -292,6 +308,133 @@ func cmdUpgrade() error {
 	return cmdDownload()
 }
 
+func upgradeBoot2DockerBinary() error {
+	var (
+		goos, arch, ext string
+	)
+	latestVersion, err := getLatestReleaseName("https://api.github.com/repos/boot2docker/boot2docker-cli/releases")
+	if err != nil {
+		return fmt.Errorf("Error attempting to get the latest boot2docker-cli release: %s", err)
+	}
+	baseUrl := "https://github.com/boot2docker/boot2docker-cli/releases/download"
+
+	ext = ""
+
+	switch runtime.GOARCH {
+	case "amd64":
+		arch = "amd64"
+	default:
+		return fmt.Errorf("Architecture not supported")
+	}
+
+	switch runtime.GOOS {
+	case "darwin", "linux":
+		goos = runtime.GOOS
+	case "windows":
+		goos = "windows"
+		arch = "windows"
+		ext = ".exe"
+	default:
+		return fmt.Errorf("Operating system not supported")
+	}
+	binaryUrl := fmt.Sprintf("%s/%s/boot2docker-%s-%s-%s%s", baseUrl, latestVersion, latestVersion, goos, arch, ext)
+	currentBoot2DockerVersion := Version
+	if err := attemptUpgrade(binaryUrl, "boot2docker", latestVersion, currentBoot2DockerVersion); err != nil {
+		return fmt.Errorf("Error attempting upgrade: %s", err)
+	}
+	return nil
+}
+
+func upgradeDockerClientBinary() error {
+	var (
+		clientOs, clientArch string
+	)
+	resp, err := http.Get("https://get.docker.com/latest")
+	if err != nil {
+		return fmt.Errorf("Error checking the latest version of Docker: %s", err)
+	}
+	defer resp.Body.Close()
+	latestVersionBytes, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("Error reading response body on latest version of Docker call: %s", err)
+	}
+	latestVersion := strings.TrimSpace(string(latestVersionBytes))
+	localClientVersion, err := getLocalClientVersion()
+	if err != nil {
+		return fmt.Errorf("Error getting local Docker client version: %s", err)
+	}
+	switch runtime.GOARCH {
+	case "amd64":
+		clientArch = "x86_64"
+	default:
+		return fmt.Errorf("Architecture not supported")
+	}
+
+	switch runtime.GOOS {
+	case "darwin":
+		clientOs = "Darwin"
+	case "linux":
+		clientOs = "Linux"
+	default:
+		return fmt.Errorf("Operating system not supported")
+	}
+	binaryUrl := fmt.Sprintf("https://get.docker.com/builds/%s/%s/docker-latest", clientOs, clientArch)
+	if err := attemptUpgrade(binaryUrl, "docker", latestVersion, localClientVersion); err != nil {
+		return fmt.Errorf("Error attempting upgrade: %s", err)
+	}
+	return nil
+}
+
+func attemptUpgrade(binaryUrl, binaryName, latestVersion, localVersion string) error {
+	if (latestVersion != localVersion && !strings.Contains(latestVersion, "rc")) || B2D.ForceUpgradeDownload {
+		if err := backupAndDownload(binaryUrl, binaryName, localVersion); err != nil {
+			return fmt.Errorf("Error attempting backup and download of Docker client binary: %s", err)
+		}
+	} else {
+		fmt.Printf("%s is up to date (%s), skipping upgrade...\n", binaryName, localVersion)
+	}
+	return nil
+}
+
+func backupAndDownload(binaryUrl, binaryName, localVersion string) error {
+	binaryPath, err := exec.LookPath(binaryName)
+	if err != nil {
+		return fmt.Errorf("Error attempting to locate local binary: %s", err)
+	}
+	path := strings.TrimSpace(string(binaryPath))
+
+	fmt.Println("Backing up existing", binaryName, "binary...")
+	if err := backupBinary(binaryName, localVersion, path); err != nil {
+		return fmt.Errorf("Error backing up docker client: %s", err)
+	}
+
+	fmt.Println("Downloading new", binaryName, "client binary...")
+	if err := download(path, binaryUrl); err != nil {
+		return fmt.Errorf("Error attempting to download new client binary: %s", err)
+	}
+	if err := os.Chmod(path, 0755); err != nil {
+		return err
+	}
+	fmt.Printf("Success: downloaded %s\n\tto %s\n\tThe old version is backed up to ~/.boot2docker.\n", binaryUrl, path)
+	return nil
+}
+
+func backupBinary(binaryName, localVersion, path string) error {
+	dir, err := cfgDir(".boot2docker")
+	if err != nil {
+		return fmt.Errorf("Error getting boot2docker config dir", err)
+	}
+	buf, err := ioutil.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("Error opening binary for reading at %s: %s", path, err)
+	}
+	backupName := fmt.Sprintf("%s-%s", binaryName, localVersion)
+	if err := ioutil.WriteFile(filepath.Join(dir, backupName), buf, 0755); err != nil {
+		return fmt.Errorf("Error creating backup file", err)
+	}
+	return nil
+}
+
 // Gracefully stop and then start the VM.
 func cmdRestart() error {
 	m, err := driver.GetMachine(&B2D)

config.go

@@ -93,6 +93,14 @@ func config() (*flag.FlagSet, error) {
 	B2D.Dir = dir
 	flags.StringVar(&B2D.ISOURL, "iso-url", "https://api.github.com/repos/boot2docker/boot2docker/releases", "source URL to provision the boot2docker ISO image.")
 	flags.StringVar(&B2D.ISO, "iso", filepath.Join(dir, "boot2docker.iso"), "path to boot2docker ISO image.")
+	if runtime.GOOS == "darwin" {
+		// clobber by default
+		flags.BoolVar(&B2D.Clobber, "clobber", true, "overwrite Docker client binary on boot2docker upgrade")
+	} else {
+		flags.BoolVar(&B2D.Clobber, "clobber", false, "overwrite Docker client binary on boot2docker upgrade")
+	}
+
+	flags.BoolVar(&B2D.ForceUpgradeDownload, "force-upgrade-download", false, "always download on boot2docker upgrade, never skip")
 
 	// Sven disabled this, as it is broken - if I user with a fresh computer downloads
 	// just the boot2docker-cli, and then runs `boot2docker --init ip`, we create a vm

driver/config.go

@@ -2,8 +2,9 @@ package driver
 
 import (
 	"fmt"
-	flag "github.com/ogier/pflag"
 	"net"
+
+	flag "github.com/ogier/pflag"
 )
 
 // Machine config.
@@ -14,15 +15,17 @@ type MachineConfig struct {
 	Driver  string
 
 	// basic config
-	SSH      string // SSH client executable
-	SSHGen   string // SSH keygen executable
-	SSHKey   string // SSH key to send to the vm
-	VM       string // virtual machine name
-	Dir      string // boot2docker directory
-	ISOURL   string // Source URL to retrieve the ISO from
-	ISO      string // boot2docker ISO image path
-	DiskSize uint   // VM disk image size (MB)
-	Memory   uint   // VM memory size (MB)
+	Clobber              bool
+	ForceUpgradeDownload bool
+	SSH                  string // SSH client executable
+	SSHGen               string // SSH keygen executable
+	SSHKey               string // SSH key to send to the vm
+	VM                   string // virtual machine name
+	Dir                  string // boot2docker directory
+	ISOURL               string // Source URL to retrieve the ISO from
+	ISO                  string // boot2docker ISO image path
+	DiskSize             uint   // VM disk image size (MB)
+	Memory               uint   // VM memory size (MB)
 
 	// NAT network: port forwarding
 	SSHPort    uint16 // host SSH port (forward to port 22 in VM)

util.go

@@ -21,6 +21,11 @@ import (
 	"github.com/boot2docker/boot2docker-cli/driver"
 )
 
+var (
+	// We're looking to get e.g. "1.2.0" from "Docker version 1.2.0, build fa7b24f"
+	versionRe = regexp.MustCompile(`(\d+\.?){3}`)
+)
+
 // Try if addr tcp://addr is readable for n times at wait interval.
 func read(addr string, n int, wait time.Duration) error {
 	var lastErr error
@@ -105,6 +110,7 @@ func getLatestReleaseName(url string) (string, error) {
 	defer rsp.Body.Close()
 
 	var t []struct {
+		Name    string `json:"name"`
 		TagName string `json:"tag_name"`
 	}
 	body, err := ioutil.ReadAll(rsp.Body)
@@ -125,7 +131,27 @@ func getLatestReleaseName(url string) (string, error) {
 	if len(t) == 0 {
 		return "", fmt.Errorf("no releases found")
 	}
-	return t[0].TagName, nil
+
+	// Looking up by tag instead of release.
+	// Github API call for docker releases yields nothing,
+	// so we use tags API call in this case.
+	name := ""
+	if strings.Contains(url, "tags") {
+		name = t[0].Name
+	} else {
+		name = t[0].TagName
+	}
+	return name, nil
+}
+
+func getLocalClientVersion() (string, error) {
+	versionOutput, err := exec.Command("docker", "-v").Output()
+	if err != nil {
+		return "", err
+	}
+	versionNumber := versionRe.FindString(string(versionOutput))
+
+	return versionNumber, nil
 }
 
 func cmdInteractive(m driver.Machine, args ...string) error {