docs: add Getting Started guide for nix users

docs/quick_start_guide.md

@@ -12,15 +12,18 @@ This guide will help you quickly set up a Lightway VPN server and client using t
 
 ### Server Requirements
 
-- Linux system (x86_64, arm64, or riscv64)
-- Root or sudo access
-- The following packages:
-  - `jq`, `yq` (for parsing server and client config.yaml files)
-  - `apache2-utils` (htpasswd for user authentication)
-  - `iproute2`
-  - `iptables`
-
-Install dependencies on Debian/Ubuntu:
+- Nix user
+  - use quick start shell
+  - `nix develop github:expressvpn/lightway#quick-start`
+- None Nix user
+  - Linux system (x86_64, arm64, or riscv64)
+  - Root or sudo access
+  - The following packages:
+    - `jq`, `yq` (for parsing server and client config.yaml files)
+    - `apache2-utils` (htpasswd for user authentication)
+    - `iproute2`
+    - `iptables`
+  - Install dependencies on Debian/Ubuntu:
 ```bash
 sudo apt-get update
 sudo apt-get install jq yq apache2-utils iproutes2 iptables
@@ -45,7 +48,11 @@ chmod +x lightway-server
 ```
 
 ### 2. Download the Setup Script
+- Nix user
+  - The script is also included in the quick-start shell, you do not need to download it.
 
+- None Nix user
+  - Download latest script from repository
 ```bash
 curl -L -o server_start.sh https://raw.githubusercontent.com/expressvpn/lightway/main/samples/server_start.sh
 chmod +x server_start.sh
@@ -104,6 +111,12 @@ Edit the config to update the database (`user_db`) and certificate paths (`serve
 
 Use the provided setup script to start the server:
 
+- Nix user
+```bash
+sudo server_start server_config.yaml
+```
+
+- None Nix user
 ```bash
 sudo ./server_start.sh server_config.yaml
 ```
@@ -151,6 +164,12 @@ Edit the config to update `server`, `ca_cert`, `user`, and `password` fields.
 
 Run the client to establish a VPN connection to the server:
 
+- Nix user
+```bash
+sudo nix run github:expressvpn/lightway#lightway-client -- --config-file client_config.yaml
+```
+
+- None Nix user
 ```bash
 sudo ./lightway-client --config-file client_config.yaml
 ```

flake.nix

@@ -80,8 +80,9 @@
             };
           clientFeatures = [ ] ++ lib.optional pkgs.stdenv.isLinux [ "io-uring" ];
           serverFeatures = [ ] ++ lib.optional pkgs.stdenv.isLinux [ "io-uring" ];
+          serverStartScript = pkgs.writeShellScriptBin "server_start" (builtins.readFile ./samples/server_start.sh);
         in
-        {
+        rec {
           _module.args.pkgs = import inputs.nixpkgs {
             inherit system;
             overlays = [ inputs.rust-overlay.overlays.default ];
@@ -98,6 +99,23 @@
           devShells.stable = mkDevShell pkgs.rust-bin.stable.latest.default;
           devShells.nightly = mkDevShell pkgs.rust-bin.nightly.latest.default;
           devShells.msrv = mkDevShell pkgs.rust-bin.stable.${msrv}.default;
+          devShells.quick-start = pkgs.mkShell {
+            shellHook = ''
+              export RUST_SRC_PATH=${pkgs.rustPlatform.rustLibSrc}
+            '';
+            buildInputs = runtimeDeps;
+            nativeBuildInputs = buildDeps ++ devDeps ++ (with pkgs; [ 
+              apacheHttpd
+              iproute2
+              iptables
+              jq
+              openssl
+              yq
+            ]) ++ [
+              packages.lightway-server
+              serverStartScript 
+            ];
+          };
 
           formatter = pkgs.nixfmt-rfc-style;
         };

samples/server_start.sh

@@ -38,7 +38,7 @@ check_dependencies() {
         exit 1
     fi
 
-    if [[ ! -f "./lightway-server" ]]; then
+    if [[ ! -f "./lightway-server" ]] && [[ ! -x "$(command -v lightway-server)" ]]; then
         echo "Error: lightway-server binary not found in current directory" >&2
         exit 1
     fi
@@ -117,5 +117,5 @@ iptables -P OUTPUT ACCEPT
 iptables -P FORWARD ACCEPT
 iptables -t nat -A POSTROUTING -s "${tun_ip_subnet}" -o "${wandev}" -j SNAT --to "${basenet}"
 
-./lightway-server -c "${VPN_SERVER_CONFIG}" "${EXTRA_ARGS[@]}"
-
+./lightway-server -c "${VPN_SERVER_CONFIG}" "${EXTRA_ARGS[@]}" ||
+    lightway-server -c "${VPN_SERVER_CONFIG}" "${EXTRA_ARGS[@]}"