vpnem: VPN infrastructure with load-balanced multi-protocol nodesHEADmain

- Multi-protocol VPS nodes (VLESS-REALITY + Hysteria2 + SOCKS5)
- Smart load balancing via recommendation API
- Windows/Linux client (Go + Wails + sing-box)
- Server API with RealIP detection and connection tracking
- Auto-deployment via vpnui control plane
- Silent Windows installer with UAC elevation
- Load-based server recommendation (no sticky sessions)
- Best Server one-click connection workflow

1 files changed, 68 insertions, 0 deletions

diff --git a/internal/control/preflight.go b/internal/control/preflight.go
new file mode 100644
index 0000000..44db7d0
--- /dev/null
+++ b/internal/control/preflight.go
@@ -0,0 +1,68 @@
+package control
+
+import "strings"
+
+func RenderPreflightInspectScript() string {
+	return `set -eu
+if [ -r /etc/os-release ]; then
+  . /etc/os-release
+fi
+printf 'OS_ID=%s\n' "${ID:-}"
+printf 'OS_PRETTY=%s\n' "${PRETTY_NAME:-}"
+printf 'OS_LIKE=%s\n' "${ID_LIKE:-}"
+if [ -d /opt/vpnem-node/current ]; then
+  printf 'MANAGED=1\n'
+else
+  printf 'MANAGED=0\n'
+fi
+if command -v docker >/dev/null 2>&1; then
+  printf 'DOCKER=1\n'
+else
+  printf 'DOCKER=0\n'
+fi
+if command -v docker >/dev/null 2>&1 && docker compose version >/dev/null 2>&1; then
+  printf 'COMPOSE=1\n'
+elif command -v docker-compose >/dev/null 2>&1; then
+  printf 'COMPOSE=1\n'
+else
+  printf 'COMPOSE=0\n'
+fi
+if command -v ss >/dev/null 2>&1; then
+  if ss -lnt 2>/dev/null | awk 'NR>1 {print $4}' | grep -Eq '(^|[:.])443$'; then
+    printf 'TCP_443=1\n'
+  else
+    printf 'TCP_443=0\n'
+  fi
+  if ss -lnu 2>/dev/null | awk 'NR>1 {print $4}' | grep -Eq '(^|[:.])443$'; then
+    printf 'UDP_443=1\n'
+  else
+    printf 'UDP_443=0\n'
+  fi
+  if ss -lnt 2>/dev/null | awk 'NR>1 {print $4}' | grep -Eq '(^|[:.])54101$'; then
+    printf 'TCP_54101=1\n'
+  else
+    printf 'TCP_54101=0\n'
+  fi
+else
+  printf 'TCP_443=unknown\n'
+  printf 'UDP_443=unknown\n'
+  printf 'TCP_54101=unknown\n'
+fi
+`
+}
+
+func ParsePreflightInspectOutput(stdout string) map[string]string {
+	values := map[string]string{}
+	for _, line := range strings.Split(stdout, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		key, value, ok := strings.Cut(line, "=")
+		if !ok {
+			continue
+		}
+		values[strings.TrimSpace(key)] = strings.TrimSpace(value)
+	}
+	return values
+}