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/proto/proto.go

@@ -103,8 +103,19 @@ type WSMsg struct {
 	Transport string          `json:"transport,omitempty"`
 	Fallback  string          `json:"fallback,omitempty"`
 	Main      string          `json:"main,omitempty"`
+	// Auto-update of agents: how often (minutes) an agent compares its
+	// version with the server's and updates itself if the server's is newer;
+	// 0 or missing - it does not. ServerVersion is the server's.
+	AutoUpdate    int    `json:"autoupdate,omitempty"`
+	ServerVersion string `json:"server_version,omitempty"`
 }
 
+// Headers with the same on the poll answer and on /api/agent/config.
+const (
+	AutoUpdateHeader    = "X-Auto-Update"    // minutes, "0" or missing: off
+	ServerVersionHeader = "X-Server-Version" // the server's release version
+)
+
 // Terminal / stream frame types on the session "in" channel (server -> agent).
 // Reused for both PTY terminals and raw TCP port-forward streams.
 const (

internal/proto/version.go

@@ -0,0 +1,50 @@
+package proto
+
+import (
+	"strconv"
+	"strings"
+)
+
+// versionParts reads "0.2.5" (a leading v and a "-suffix" are allowed) as
+// numbers; ok is false for anything that is not a dotted number.
+func versionParts(v string) (parts []int, ok bool) {
+	v = strings.TrimPrefix(strings.TrimSpace(v), "v")
+	if i := strings.IndexAny(v, "-+"); i >= 0 {
+		v = v[:i]
+	}
+	if v == "" {
+		return nil, false
+	}
+	for _, p := range strings.Split(v, ".") {
+		n, err := strconv.Atoi(p)
+		if err != nil || n < 0 {
+			return nil, false
+		}
+		parts = append(parts, n)
+	}
+	return parts, true
+}
+
+// VersionNewer reports whether version a is higher than b. Anything that is
+// not a dotted number (a build named "dev", an empty string) is never newer
+// and never older - so a program is never "updated" down, or from a guess.
+func VersionNewer(a, b string) bool {
+	pa, okA := versionParts(a)
+	pb, okB := versionParts(b)
+	if !okA || !okB {
+		return false
+	}
+	for i := 0; i < len(pa) || i < len(pb); i++ {
+		var x, y int
+		if i < len(pa) {
+			x = pa[i]
+		}
+		if i < len(pb) {
+			y = pb[i]
+		}
+		if x != y {
+			return x > y
+		}
+	}
+	return false
+}

internal/proto/version_test.go

@@ -0,0 +1,30 @@
+package proto
+
+import "testing"
+
+// A version is newer only when it is a higher dotted number: never for the
+// same, an older one, or what is not a version at all.
+func TestVersionNewer(t *testing.T) {
+	for _, c := range []struct {
+		a, b string
+		want bool
+	}{
+		{"0.2.5", "0.2.4", true},
+		{"0.2.10", "0.2.9", true},
+		{"0.3.0", "0.2.99", true},
+		{"1.0", "0.9.9", true},
+		{"0.2.4", "0.2.4", false},
+		{"0.2.3", "0.2.4", false},
+		{"0.2", "0.2.0", false},
+		{"v0.2.5", "0.2.4", true},
+		{"", "0.2.4", false},
+		{"dev", "0.2.4", false},
+		{"0.2.5", "dev", false},
+		{"0.2.5", "", false},
+		{"0.2.5-rc1", "0.2.4", true},
+	} {
+		if got := VersionNewer(c.a, c.b); got != c.want {
+			t.Errorf("VersionNewer(%q, %q) = %v, want %v", c.a, c.b, got, c.want)
+		}
+	}
+}