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)
+		}
+	}
+}

internal/agent/autoupdate_test.go

@@ -0,0 +1,78 @@
+package agent
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
+)
+
+// updates counts what an agent was made to update with.
+type updates struct{ n int }
+
+func (u *updates) do() proto.TaskResult { u.n++; return proto.TaskResult{OK: true} }
+
+// The agent is told, by headers or by the WebSocket's message, how often to
+// compare versions; nothing told, nothing done.
+func TestAutoUpdateIsTold(t *testing.T) {
+	a := New(Config{})
+	if a.autoUpdateOn() {
+		t.Fatal("on with nothing told")
+	}
+	h := http.Header{}
+	h.Set(proto.AutoUpdateHeader, "90")
+	h.Set(proto.ServerVersionHeader, "9.9.9")
+	a.applyUpdateHeaders(h)
+	if m, v := a.updateInfo(); m != 90 || v != "9.9.9" {
+		t.Fatalf("by headers: %d %q", m, v)
+	}
+	a.applyUpdateInfo(0, "9.9.9")
+	if a.autoUpdateOn() {
+		t.Fatal("still on after being told 0")
+	}
+	a.applyUpdateInfo(30, "9.9.9")
+	if m, _ := a.updateInfo(); m != 30 {
+		t.Fatalf("by the message: %d", m)
+	}
+	// Rubbish is not taken for a number.
+	h.Set(proto.AutoUpdateHeader, "soon")
+	a.applyUpdateHeaders(h)
+	if m, _ := a.updateInfo(); m != 0 {
+		t.Fatalf("rubbish: %d", m)
+	}
+}
+
+// When the interval is out the agent looks; it updates only to a newer
+// version of the server's, and tries again the next time if it did not work.
+func TestAutoUpdateTick(t *testing.T) {
+	a := New(Config{})
+	u := &updates{}
+	now := time.Now()
+	a.applyUpdateInfo(60, "9.9.9")
+
+	if !a.autoUpdateTick(now, u.do) || u.n != 1 {
+		t.Fatalf("a newer server: %d updates", u.n)
+	}
+	if a.autoUpdateTick(now.Add(30*time.Minute), u.do) || u.n != 1 {
+		t.Fatalf("before the interval is out: %d updates", u.n)
+	}
+	if !a.autoUpdateTick(now.Add(61*time.Minute), u.do) || u.n != 2 {
+		t.Fatalf("at the next time: %d updates", u.n)
+	}
+
+	// The same, an older one, a build that is not a version: nothing.
+	for _, v := range []string{Version, "0.0.1", "dev", ""} {
+		b := New(Config{})
+		b.applyUpdateInfo(60, v)
+		if b.autoUpdateTick(now, u.do) {
+			t.Fatalf("updated to %q", v)
+		}
+	}
+	// Off: nothing, whatever the server has.
+	c := New(Config{})
+	c.applyUpdateInfo(0, "9.9.9")
+	if c.autoUpdateTick(now, u.do) || u.n != 2 {
+		t.Fatalf("off, yet updated: %d", u.n)
+	}
+}

internal/agent/client.go

@@ -64,6 +64,8 @@ type Agent struct {
 	tunMu     sync.Mutex
 	tunAddr   string
 	tunCancel context.CancelFunc
+
+	auto autoUpdate // what the server told of auto-update
 }
 
 // New builds an agent. It does not perform any network I/O.
@@ -115,6 +117,7 @@ func (a *Agent) Run(ctx context.Context) error {
 		}
 	}
 	go a.watchMain(ctx)
+	go a.autoUpdateLoop(ctx)
 	log.Printf("agent %s connected to %s", a.state.AgentID, a.host())
 
 	// Direct forward tunnel (low-latency TCP mux + UDP). Its address comes
@@ -321,6 +324,7 @@ func (a *Agent) pollOnce(ctx, reqCtx context.Context) error {
 	a.applyTunnelHeader(ctx, resp.Header)
 	a.learnAddrs(resp.Header.Get(proto.MainHeader), resp.Header.Get(proto.FallbackHeader))
 	a.applyTransport(resp.Header.Get(proto.TransportHeader))
+	a.applyUpdateHeaders(resp.Header)
 	a.dispatch(ctx, msg)
 	return nil
 }
@@ -356,6 +360,7 @@ func (a *Agent) fetchConfig(ctx context.Context) bool {
 	defer resp.Body.Close()
 	a.applyTransport(resp.Header.Get(proto.TransportHeader))
 	a.learnAddrs(resp.Header.Get(proto.MainHeader), resp.Header.Get(proto.FallbackHeader))
+	a.applyUpdateHeaders(resp.Header)
 	return a.applyTunnelHeader(ctx, resp.Header)
 }
 

internal/agent/wslink.go

@@ -167,6 +167,7 @@ func (a *Agent) runWS(ctx context.Context) error {
 			a.applyTunnelAddr(ctx, m.Tunnel)
 			a.learnAddrs(m.Main, m.Fallback)
 			a.applyTransport(m.Transport)
+			a.applyUpdateInfo(m.AutoUpdate, m.ServerVersion)
 			if a.mode() == proto.TransportLP {
 				return errors.New("set to long polling")
 			}