Feature/update check (#1232)

Periodically fetch the latest available version, and the UI will shows a new menu for the download link. It checks both the daemon version and the UI version.

version/update.go

@@ -0,0 +1,184 @@
+package version
+
+import (
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
+	goversion "github.com/hashicorp/go-version"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	fetchPeriod = 30 * time.Minute
+)
+
+var (
+	versionURL = "https://pkgs.netbird.io/releases/latest/version"
+)
+
+// Update fetch the version info periodically and notify the onUpdateListener in case the UI version or the
+// daemon version are deprecated
+type Update struct {
+	uiVersion       *goversion.Version
+	daemonVersion   *goversion.Version
+	latestAvailable *goversion.Version
+	versionsLock    sync.Mutex
+
+	fetchTicker *time.Ticker
+	fetchDone   chan struct{}
+
+	onUpdateListener func()
+	listenerLock     sync.Mutex
+}
+
+// NewUpdate instantiate Update and start to fetch the new version information
+func NewUpdate() *Update {
+	currentVersion, err := goversion.NewVersion(version)
+	if err != nil {
+		currentVersion, _ = goversion.NewVersion("0.0.0")
+	}
+
+	latestAvailable, _ := goversion.NewVersion("0.0.0")
+
+	u := &Update{
+		latestAvailable: latestAvailable,
+		uiVersion:       currentVersion,
+		fetchTicker:     time.NewTicker(fetchPeriod),
+		fetchDone:       make(chan struct{}),
+	}
+	go u.startFetcher()
+	return u
+}
+
+// StopWatch stop the version info fetch loop
+func (u *Update) StopWatch() {
+	u.fetchTicker.Stop()
+
+	select {
+	case u.fetchDone <- struct{}{}:
+	default:
+	}
+}
+
+// SetDaemonVersion update the currently running daemon version. If new version is available it will trigger
+// the onUpdateListener
+func (u *Update) SetDaemonVersion(newVersion string) bool {
+	daemonVersion, err := goversion.NewVersion(newVersion)
+	if err != nil {
+		daemonVersion, _ = goversion.NewVersion("0.0.0")
+	}
+
+	u.versionsLock.Lock()
+	if u.daemonVersion != nil && u.daemonVersion.Equal(daemonVersion) {
+		u.versionsLock.Unlock()
+		return false
+	}
+
+	u.daemonVersion = daemonVersion
+	u.versionsLock.Unlock()
+	return u.checkUpdate()
+}
+
+// SetOnUpdateListener set new update listener
+func (u *Update) SetOnUpdateListener(updateFn func()) {
+	u.listenerLock.Lock()
+	defer u.listenerLock.Unlock()
+
+	u.onUpdateListener = updateFn
+	if u.isUpdateAvailable() {
+		u.onUpdateListener()
+	}
+}
+
+func (u *Update) startFetcher() {
+	changed := u.fetchVersion()
+	if changed {
+		u.checkUpdate()
+	}
+
+	select {
+	case <-u.fetchDone:
+		return
+	case <-u.fetchTicker.C:
+		changed := u.fetchVersion()
+		if changed {
+			u.checkUpdate()
+		}
+	}
+}
+
+func (u *Update) fetchVersion() bool {
+	resp, err := http.Get(versionURL)
+	if err != nil {
+		log.Errorf("failed to fetch version info: %s", err)
+		return false
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		log.Errorf("invalid status code: %d", resp.StatusCode)
+		return false
+	}
+
+	if resp.ContentLength > 100 {
+		log.Errorf("too large response: %d", resp.ContentLength)
+		return false
+	}
+
+	content, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Errorf("failed to read content: %s", err)
+		return false
+	}
+
+	latestAvailable, err := goversion.NewVersion(string(content))
+	if err != nil {
+		log.Errorf("failed to parse the version string: %s", err)
+		return false
+	}
+
+	u.versionsLock.Lock()
+	defer u.versionsLock.Unlock()
+
+	if u.latestAvailable.Equal(latestAvailable) {
+		return false
+	}
+	u.latestAvailable = latestAvailable
+
+	return true
+}
+
+func (u *Update) checkUpdate() bool {
+	if !u.isUpdateAvailable() {
+		return false
+	}
+
+	u.listenerLock.Lock()
+	defer u.listenerLock.Unlock()
+	if u.onUpdateListener == nil {
+		return true
+	}
+
+	go u.onUpdateListener()
+	return true
+}
+
+func (u *Update) isUpdateAvailable() bool {
+	u.versionsLock.Lock()
+	defer u.versionsLock.Unlock()
+
+	if u.latestAvailable.GreaterThan(u.uiVersion) {
+		return true
+	}
+
+	if u.daemonVersion == nil {
+		return false
+	}
+
+	if u.latestAvailable.GreaterThan(u.daemonVersion) {
+		return true
+	}
+	return false
+}