feat: Настройки › Автообновление - clients compare their version with the server's every N and update themselves; the server looks at GitLab every N and, when a newer release is out, offers it to an administrator at login (after the PIN) with «Обновить» and «Отказаться»; the words of a made picture's result are the model's only

internal/agent/autoupdate.go

@@ -0,0 +1,95 @@
+package agent
+
+import (
+	"context"
+	"log"
+	"net/http"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// Auto-update, the agent's part: the server tells (with every poll, on its
+// config and on the WebSocket) its own version and how often to compare -
+// in minutes, 0 for never. When the server's version is newer, the agent
+// takes the new one from it, as the panel's «Обновить» does.
+
+// autoUpdate is what the agent was told, and when it last looked.
+type autoUpdate struct {
+	mu        sync.Mutex
+	minutes   int
+	serverVer string
+	last      time.Time
+}
+
+func (a *Agent) applyUpdateInfo(minutes int, serverVersion string) {
+	a.auto.mu.Lock()
+	defer a.auto.mu.Unlock()
+	if minutes < 0 {
+		minutes = 0
+	}
+	a.auto.minutes = minutes
+	if serverVersion != "" {
+		a.auto.serverVer = serverVersion
+	}
+}
+
+// applyUpdateHeaders takes the settings from the headers of an answer; an
+// answer without them (an older server) changes nothing.
+func (a *Agent) applyUpdateHeaders(h http.Header) {
+	v := h.Get(proto.AutoUpdateHeader)
+	if v == "" {
+		return
+	}
+	m, err := strconv.Atoi(v)
+	if err != nil {
+		m = 0
+	}
+	a.applyUpdateInfo(m, h.Get(proto.ServerVersionHeader))
+}
+
+func (a *Agent) updateInfo() (int, string) {
+	a.auto.mu.Lock()
+	defer a.auto.mu.Unlock()
+	return a.auto.minutes, a.auto.serverVer
+}
+
+func (a *Agent) autoUpdateOn() bool { m, _ := a.updateInfo(); return m > 0 }
+
+// autoUpdateTick: one look at the clock. Out of the interval since the last
+// look, it looks; the server's version newer than its own, it updates.
+// Reports whether it did.
+func (a *Agent) autoUpdateTick(now time.Time, update func() proto.TaskResult) bool {
+	a.auto.mu.Lock()
+	if a.auto.minutes <= 0 || (!a.auto.last.IsZero() && now.Sub(a.auto.last) < time.Duration(a.auto.minutes)*time.Minute) {
+		a.auto.mu.Unlock()
+		return false
+	}
+	a.auto.last = now
+	server := a.auto.serverVer
+	a.auto.mu.Unlock()
+	if !proto.VersionNewer(server, Version) {
+		return false
+	}
+	log.Printf("auto-update: server has %s, this is %s - updating", server, Version)
+	if res := update(); !res.OK {
+		log.Printf("auto-update: %s", res.Error)
+	}
+	return true
+}
+
+// autoUpdateLoop watches the clock until ctx ends.
+func (a *Agent) autoUpdateLoop(ctx context.Context) {
+	t := time.NewTicker(30 * time.Second)
+	defer t.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case now := <-t.C:
+			a.autoUpdateTick(now, a.doUpdate)
+		}
+	}
+}