Add resolvconf shim to stabilize WireGuard DNS handling

qbittorrent/rootfs/etc/s6-overlay/s6-rc.d/svc-qbittorrent/run

@@ -3,6 +3,8 @@
 
 WEBUI_PORT=${WEBUI_PORT:-8080}
 
+export PATH="/usr/local/sbin:/usr/local/bin:${PATH}"
+
 if bashio::config.true 'silent'; then
     sed -i 's|/proc/1/fd/1 hassio;|off;|g' /etc/nginx/nginx.conf
 fi

qbittorrent/rootfs/usr/local/bin/resolvconf

@@ -0,0 +1,86 @@
+#!/bin/sh
+set -eu
+
+STATE_DIR="/var/run/wireguard/resolvconf"
+BACKUP_FILE="${STATE_DIR}/resolv.conf.backup"
+
+mkdir -p "${STATE_DIR}"
+
+if [ "$#" -eq 0 ]; then
+    exit 0
+fi
+
+command="$1"
+shift || true
+
+restore_backup() {
+    if [ -f "${BACKUP_FILE}" ]; then
+        cat "${BACKUP_FILE}" > /etc/resolv.conf
+    fi
+}
+
+apply_dns() {
+    iface="$1"
+    shift || true
+
+    # Skip optional arguments such as -m <metric> or -x
+    while [ "$#" -gt 0 ]; do
+        case "$1" in
+            -m|-p|-w)
+                shift 2 || true
+                ;;
+            -x|-y|-Z)
+                shift 1 || true
+                ;;
+            --)
+                shift
+                break
+                ;;
+            *)
+                break
+                ;;
+        esac
+    done
+
+    tmp_file="${STATE_DIR}/${iface}.conf"
+    cat > "${tmp_file}"
+
+    if [ ! -f "${BACKUP_FILE}" ]; then
+        cp /etc/resolv.conf "${BACKUP_FILE}" 2>/dev/null || true
+    fi
+
+    {
+        echo "# Generated by WireGuard add-on resolvconf shim"
+        cat "${tmp_file}"
+    } > /etc/resolv.conf
+}
+
+case "${command}" in
+    -a)
+        if [ "$#" -eq 0 ]; then
+            exit 0
+        fi
+        apply_dns "$@"
+        ;;
+    -d)
+        if [ "$#" -gt 0 ]; then
+            rm -f "${STATE_DIR}/$1.conf"
+        fi
+        restore_backup
+        ;;
+    -u)
+        latest_conf="$(find "${STATE_DIR}" -maxdepth 1 -type f -name '*.conf' -print | head -n 1 || true)"
+        if [ -n "${latest_conf}" ] && [ -f "${latest_conf}" ]; then
+            {
+                echo "# Generated by WireGuard add-on resolvconf shim"
+                cat "${latest_conf}"
+            } > /etc/resolv.conf
+        else
+            restore_backup
+        fi
+        ;;
+    *)
+        # Treat other commands as successful no-ops to remain compatible with wg-quick.
+        exit 0
+        ;;
+esac