Add wg-quick/systemctl service control and bulk-delete list views

Per-server Start/Stop/Restart via systemd wg-quick@<iface>.service units
plus live status badge, and a table/list-view toggle with checkbox
bulk-delete for both the server list and per-server client list.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PvrfUytqd74H6WcQkRzFM4

wireguard/service.go

@@ -0,0 +1,88 @@
+package wireguard
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+
+	"github.com/ngoduykhanh/wireguard-ui/util"
+)
+
+// UnitName returns the systemd unit name managing the given WireGuard
+// interface via wg-quick, e.g. "wg-quick@wg-home.service".
+func UnitName(iface string) string {
+	return "wg-quick@" + iface + ".service"
+}
+
+// Start brings up the given WireGuard interface via
+// `systemctl start wg-quick@<iface>.service`.
+func Start(ctx context.Context, iface string) error {
+	return runSystemctl(ctx, "start", iface)
+}
+
+// Stop brings down the given WireGuard interface via
+// `systemctl stop wg-quick@<iface>.service`.
+func Stop(ctx context.Context, iface string) error {
+	return runSystemctl(ctx, "stop", iface)
+}
+
+// Restart restarts the given WireGuard interface via
+// `systemctl restart wg-quick@<iface>.service`.
+func Restart(ctx context.Context, iface string) error {
+	return runSystemctl(ctx, "restart", iface)
+}
+
+func runSystemctl(ctx context.Context, action, iface string) error {
+	if !util.ValidateInterfaceName(iface) {
+		return fmt.Errorf("invalid interface name: %q", iface)
+	}
+	cmd := exec.CommandContext(ctx, "systemctl", action, UnitName(iface))
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("systemctl %s %s failed: %w: %s", action, UnitName(iface), err, string(out))
+	}
+	return nil
+}
+
+// Status reports whether the given WireGuard interface's wg-quick unit is
+// currently active and whether it is enabled to start on boot. Only real
+// exec failures (e.g. systemctl binary missing) are returned as err - a
+// unit being inactive/disabled/failed is a normal, non-error result
+// reflected in the returned booleans.
+func Status(ctx context.Context, iface string) (active bool, enabled bool, err error) {
+	if !util.ValidateInterfaceName(iface) {
+		return false, false, fmt.Errorf("invalid interface name: %q", iface)
+	}
+
+	unit := UnitName(iface)
+
+	active, err = systemctlBoolCheck(ctx, "is-active", unit)
+	if err != nil {
+		return false, false, err
+	}
+
+	enabled, err = systemctlBoolCheck(ctx, "is-enabled", unit)
+	if err != nil {
+		return active, false, err
+	}
+
+	return active, enabled, nil
+}
+
+// systemctlBoolCheck runs `systemctl <verb> <unit>` and interprets a
+// non-zero exit code as a normal "false" result (inactive/disabled/failed),
+// not an error. Only a failure to execute systemctl at all (binary missing,
+// context cancelled, ...) is surfaced as err.
+func systemctlBoolCheck(ctx context.Context, verb, unit string) (bool, error) {
+	cmd := exec.CommandContext(ctx, "systemctl", verb, unit)
+	err := cmd.Run()
+	if err == nil {
+		return true, nil
+	}
+	if _, ok := err.(*exec.ExitError); ok {
+		// systemctl ran fine and just reported a non-active/non-enabled
+		// state via its exit code - not an execution error.
+		return false, nil
+	}
+	return false, fmt.Errorf("systemctl %s %s failed to execute: %w", verb, unit, err)
+}