feat: add notify scripts for state transitions

- Add notify_master/notify_backup/notify_fault support
- Support both file path and inline shell script
- Async execution with 60s timeout
- Inject GO_ALIVED_INSTANCE and GO_ALIVED_EVENT env vars
- Bump version to 1.3.0

🤖 Generated with [Qoder][https://qoder.com]

.github/workflows/release.yml

@@ -0,0 +1,95 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    name: Build ${{ matrix.os }}-${{ matrix.arch }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - os: linux
+            arch: amd64
+          - os: linux
+            arch: arm64
+          - os: darwin
+            arch: amd64
+          - os: darwin
+            arch: arm64
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.21'
+
+      - name: Get version
+        id: version
+        run: echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.os }}
+          GOARCH: ${{ matrix.arch }}
+          CGO_ENABLED: 0
+        run: |
+          mkdir -p dist
+          BINARY_NAME=go-alived-${{ matrix.os }}-${{ matrix.arch }}
+          if [ "${{ matrix.os }}" = "windows" ]; then
+            BINARY_NAME="${BINARY_NAME}.exe"
+          fi
+          go build -ldflags="-s -w -X github.com/loveuer/go-alived/internal/cmd.Version=${{ steps.version.outputs.VERSION }}" \
+            -o dist/${BINARY_NAME} .
+          
+          # Create checksum
+          cd dist && sha256sum ${BINARY_NAME} > ${BINARY_NAME}.sha256
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: go-alived-${{ matrix.os }}-${{ matrix.arch }}
+          path: dist/
+
+  release:
+    name: Create Release
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Download all artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: artifacts
+
+      - name: Prepare release files
+        run: |
+          mkdir -p release
+          find artifacts -type f -exec cp {} release/ \;
+          ls -la release/
+
+      - name: Get version
+        id: version
+        run: echo "VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Create Release
+        uses: softprops/action-gh-release@v1
+        with:
+          name: Release ${{ steps.version.outputs.VERSION }}
+          draft: false
+          prerelease: ${{ contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') }}
+          generate_release_notes: true
+          files: release/*
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -1,40 +1,35 @@
 # go-alived
 
-A lightweight, dependency-free VRRP (Virtual Router Redundancy Protocol) implementation in Go, designed as a simple alternative to keepalived.
+A lightweight VRRP (Virtual Router Redundancy Protocol) implementation in Go, designed as a simple alternative to keepalived.
 
 ## Features
 
-✅ **Phase 1: Core VRRP Functionality (Completed)**
-- VRRP protocol implementation (RFC 3768/5798)
-- Virtual IP management (add/remove VIPs)
-- State machine (INIT/BACKUP/MASTER/FAULT)
-- Priority-based master election
-- Gratuitous ARP for network updates
-- Raw socket VRRP packet send/receive
-- Timer management (advertisement & master-down timers)
-- VRRP instance manager with multi-instance support
-- Configuration hot-reload (SIGHUP)
-
-✅ **Phase 2: Health Checking (Completed)**
-- Health checker interface with rise/fall logic
-- TCP health checks
-- HTTP/HTTPS health checks
-- ICMP ping checks
-- Script-based checks (custom commands)
-- Periodic health check scheduling
-- Health check integration with VRRP priority
-- Track scripts: automatic priority adjustment on health changes
-
-🚧 **Phase 3: Enhanced Features (Planned)**
-- State transition scripts (notify_master/backup/fault)
-- Email/Webhook notifications
-- Sync groups
-- Virtual MAC support
-- Metrics export
+- **VRRP Protocol**: RFC 3768/5798 compliant implementation
+- **High Availability**: Automatic failover with priority-based master election
+- **Health Checking**: TCP, HTTP/HTTPS, ICMP ping, and script-based checks
+- **Easy Deployment**: Built-in install command with systemd/init.d support
+- **Hot Reload**: Configuration reload via SIGHUP without service restart
+- **Zero Dependencies**: Single static binary, no runtime dependencies
 
 ## Installation
 
-### Build from source
+### Download Binary
+
+Download the latest release from [GitHub Releases](https://github.com/loveuer/go-alived/releases):
+
+```bash
+# Linux amd64
+curl -LO https://github.com/loveuer/go-alived/releases/latest/download/go-alived-linux-amd64
+chmod +x go-alived-linux-amd64
+sudo mv go-alived-linux-amd64 /usr/local/bin/go-alived
+
+# Linux arm64
+curl -LO https://github.com/loveuer/go-alived/releases/latest/download/go-alived-linux-arm64
+chmod +x go-alived-linux-arm64
+sudo mv go-alived-linux-arm64 /usr/local/bin/go-alived
+```
+
+### Build from Source
 
 ```bash
 git clone https://github.com/loveuer/go-alived.git
@@ -42,190 +37,246 @@ cd go-alived
 go build -o go-alived .
 ```
 
+### Quick Install (Recommended)
+
+```bash
+# Install as systemd service (default)
+sudo ./go-alived install
+
+# Install as init.d service (for OpenWrt/older systems)
+sudo ./go-alived install --method service
+```
+
 ## Quick Start
 
-### 1. Test Your Environment
-
-Before deployment, test if your environment supports VRRP:
+### 1. Test Environment
 
 ```bash
-# Basic test (auto-detect network interface)
-sudo ./go-alived test
+# Check if your environment supports VRRP
+sudo go-alived test
 
-# Test specific interface
-sudo ./go-alived test -i eth0
-
-# Full test with VIP
-sudo ./go-alived test -i eth0 -v 192.168.1.100/24
+# Test with specific interface
+sudo go-alived test -i eth0
 ```
 
-### 2. Run the Service
+### 2. Configure
+
+Edit `/etc/go-alived/config.yaml`:
+
+```yaml
+global:
+  router_id: "node1"
+
+vrrp_instances:
+  - name: "VI_1"
+    interface: "eth0"          # Network interface
+    state: "BACKUP"            # Initial state
+    virtual_router_id: 51      # VRID (1-255, must match on all nodes)
+    priority: 100              # Higher = more likely to be master
+    advert_interval: 1         # Advertisement interval in seconds
+    auth_type: "PASS"          # Authentication type
+    auth_pass: "secret"        # Password (max 8 chars)
+    virtual_ips:
+      - "192.168.1.100/24"     # Virtual IP address(es)
+```
+
+### 3. Start Service
 
 ```bash
-# Run with minimal config
-sudo ./go-alived run -c config.mini.yaml -d
-
-# Run with full config
-sudo ./go-alived -c config.yaml
-
-# Install as systemd service
-sudo ./deployment/install.sh
+# Systemd
+sudo systemctl daemon-reload
+sudo systemctl enable go-alived
 sudo systemctl start go-alived
+
+# Init.d
+sudo /etc/init.d/go-alived start
 ```
 
-## Usage
+### 4. Verify
 
-### Commands
+```bash
+# Check service status
+sudo systemctl status go-alived
 
+# Check VIP
+ip addr show eth0 | grep 192.168.1.100
+
+# View logs
+sudo journalctl -u go-alived -f
 ```
-go-alived              # Run VRRP service (default)
-go-alived run          # Run VRRP service
-go-alived test         # Test environment for VRRP support
-go-alived --help       # Show help
-go-alived --version    # Show version
-```
-
-### Global Flags
-
-```
--c, --config string    Path to configuration file (default "/etc/go-alived/config.yaml")
--d, --debug            Enable debug mode
--h, --help             Show help
--v, --version          Show version
-```
-
-### Test Command Flags
-
-```
--i, --interface string    Network interface to test (auto-detect if not specified)
--v, --vip string          Test VIP address (e.g., 192.168.1.100/24)
-```
-
-See [USAGE.md](USAGE.md) for detailed usage documentation.
 
 ## Configuration
 
-### Minimal Configuration
+### Two-Node HA Setup Example
 
+**Node 1 (Primary)**:
 ```yaml
-# config.mini.yaml - VRRP only
 global:
   router_id: "node1"
 
 vrrp_instances:
   - name: "VI_1"
     interface: "eth0"
-    state: "BACKUP"
+    state: "MASTER"
     virtual_router_id: 51
-    priority: 100
+    priority: 100              # Higher priority
     advert_interval: 1
     auth_type: "PASS"
-    auth_pass: "secret123"
+    auth_pass: "secret"
     virtual_ips:
       - "192.168.1.100/24"
 ```
 
-### Full Configuration Example
+**Node 2 (Backup)**:
+```yaml
+global:
+  router_id: "node2"
 
-See `config.example.yaml` for complete configuration with health checking.
+vrrp_instances:
+  - name: "VI_1"
+    interface: "eth0"
+    state: "BACKUP"
+    virtual_router_id: 51
+    priority: 90               # Lower priority
+    advert_interval: 1
+    auth_type: "PASS"
+    auth_pass: "secret"        # Must match
+    virtual_ips:
+      - "192.168.1.100/24"     # Must match
+```
 
-### Signals
+### Health Checking
 
-- `SIGHUP`: Reload configuration
-- `SIGINT/SIGTERM`: Graceful shutdown
+```yaml
+vrrp_instances:
+  - name: "VI_1"
+    # ... other settings ...
+    track_scripts:
+      - "check_nginx"          # Reference to health checker
 
-## Architecture
+health_checkers:
+  - name: "check_nginx"
+    type: "tcp"
+    interval: 3s
+    timeout: 2s
+    rise: 3                    # Successes to mark healthy
+    fall: 2                    # Failures to mark unhealthy
+    config:
+      host: "127.0.0.1"
+      port: 80
+```
+
+**Supported Health Check Types**:
+
+| Type | Description | Config |
+|------|-------------|--------|
+| `tcp` | TCP port check | `host`, `port` |
+| `http` | HTTP endpoint check | `url`, `method`, `expected_status` |
+| `ping` | ICMP ping check | `host`, `count` |
+| `script` | Custom script | `script`, `args` |
+
+## Commands
 
 ```
-go-alived/
-├── main.go                 # Application entry point
-├── internal/
-│   ├── cmd/               # Cobra commands
-│   │   ├── root.go        # Root command
-│   │   ├── run.go         # Run service command
-│   │   └── test.go        # Environment test command
-│   ├── vrrp/              # VRRP implementation
-│   │   ├── packet.go      # VRRP packet structure & marshaling
-│   │   ├── socket.go      # Raw socket operations
-│   │   ├── state.go       # State machine & timers
-│   │   ├── arp.go         # Gratuitous ARP
-│   │   ├── instance.go    # VRRP instance logic
-│   │   └── manager.go     # Instance manager
-│   └── health/            # Health check system
-│       ├── checker.go     # Checker interface & state
-│       ├── monitor.go     # Health check scheduler
-│       ├── tcp.go         # TCP health checker
-│       ├── http.go        # HTTP/HTTPS health checker
-│       ├── ping.go        # ICMP ping checker
-│       ├── script.go      # Script checker
-│       └── factory.go     # Checker factory
-├── pkg/
-│   ├── config/            # Configuration loading & validation
-│   ├── logger/            # Logging system
-│   └── netif/             # Network interface management
-└── deployment/            # Deployment files
-    ├── go-alived.service  # Systemd service file
-    ├── install.sh         # Installation script
-    ├── uninstall.sh       # Uninstallation script
-    ├── check-env.sh       # Environment check script
-    ├── README.md          # Deployment documentation
-    └── COMPATIBILITY.md   # Environment compatibility guide
+go-alived [command]
+
+Available Commands:
+  run         Run the VRRP service
+  test        Test environment for VRRP support
+  install     Install go-alived as a system service (alias: i)
+  help        Help about any command
+
+Flags:
+  -h, --help      help for go-alived
+  -v, --version   version for go-alived
+```
+
+### run
+
+```bash
+go-alived run [flags]
+
+Flags:
+  -c, --config string   Path to config file (default "/etc/go-alived/config.yaml")
+  -d, --debug           Enable debug mode
+```
+
+### test
+
+```bash
+go-alived test [flags]
+
+Flags:
+  -i, --interface string   Network interface to test
+  -v, --vip string         Test VIP address (e.g., 192.168.1.100/24)
+```
+
+### install
+
+```bash
+go-alived install [flags]
+
+Flags:
+  -m, --method string   Installation method: systemd, service (default "systemd")
+
+Aliases:
+  install, i
+```
+
+## Signals
+
+| Signal | Action |
+|--------|--------|
+| `SIGHUP` | Reload configuration |
+| `SIGINT` / `SIGTERM` | Graceful shutdown |
+
+```bash
+# Reload configuration
+sudo kill -HUP $(pgrep go-alived)
 ```
 
 ## Environment Compatibility
 
-### ✅ Fully Supported
-- Physical servers
-- KVM/QEMU virtual machines
-- Proxmox VE
-- VMware ESXi (with promiscuous mode)
-- VirtualBox (with bridged network + promiscuous mode)
+| Environment | Support | Notes |
+|-------------|---------|-------|
+| Physical servers | Full | |
+| KVM/QEMU/Proxmox | Full | |
+| VMware ESXi | Full | Enable promiscuous mode |
+| VirtualBox | Full | Bridged network + promiscuous mode |
+| Docker | Limited | Requires `--privileged --net=host` |
+| OpenWrt/iStoreOS | Full | Use `--method service` for install |
+| AWS/Aliyun/Azure | None | Multicast disabled |
 
-### ⚠️ Limited Support
-- Private cloud (depends on network configuration)
-- Docker containers (requires `--privileged` and `--net=host`)
-- Kubernetes (requires hostNetwork mode)
+> **Note**: VRRP requires multicast support (224.0.0.18). Most public clouds disable multicast at the network layer. Use cloud-native HA solutions instead.
 
-### ❌ Not Supported
-- AWS EC2 (multicast disabled)
-- Aliyun ECS (multicast disabled)
-- Azure VM (requires special configuration)
-- Google Cloud (multicast disabled by default)
+## Troubleshooting
 
-**Why?** Public clouds typically disable multicast protocols (224.0.0.18) at the network virtualization layer.
+### Common Issues
 
-**Alternative**: Use cloud-native solutions like Elastic IP (AWS), SLB/HaVip (Aliyun), Load Balancer (Azure/GCP).
+**1. "permission denied" or "operation not permitted"**
+```bash
+# VRRP requires root privileges
+sudo go-alived run -c /etc/go-alived/config.yaml
+```
 
-See [deployment/COMPATIBILITY.md](deployment/COMPATIBILITY.md) for detailed compatibility information.
+**2. "authentication failed"**
+- Ensure `auth_pass` matches on all nodes
+- Password is limited to 8 characters
 
-## Requirements
+**3. Both nodes become MASTER (split-brain)**
+- Check network connectivity between nodes
+- Verify `virtual_router_id` matches
+- Ensure multicast traffic is allowed
 
-- Go 1.21+ (for building)
-- Linux/macOS with root privileges (for raw sockets and interface management)
-- Network interface with IPv4 address
-- Multicast support (for VRRP)
+**4. VIP not pingable after failover**
+- Gratuitous ARP may be blocked
+- Check switch/router ARP cache timeout
 
-## Dependencies
+### Debug Mode
 
-Minimal external dependencies:
-- `github.com/vishvananda/netlink` - Network interface management
-- `github.com/mdlayher/arp` - ARP packet handling
-- `github.com/spf13/cobra` - CLI framework
-- `golang.org/x/net/ipv4` - IPv4 raw socket support
-- `golang.org/x/net/icmp` - ICMP ping support
-- `gopkg.in/yaml.v3` - YAML configuration parsing
-
-## Documentation
-
-- [USAGE.md](USAGE.md) - Detailed usage guide
-- [TESTING.md](TESTING.md) - Testing guide
-- [deployment/README.md](deployment/README.md) - Deployment guide
-- [deployment/COMPATIBILITY.md](deployment/COMPATIBILITY.md) - Environment compatibility
-- [roadmap.md](roadmap.md) - Implementation roadmap
-
-## Roadmap
-
-See [roadmap.md](roadmap.md) for detailed implementation plan.
+```bash
+sudo go-alived run -c /etc/go-alived/config.yaml -d
+```
 
 ## License
 

internal/cmd/install.go

@@ -0,0 +1,466 @@
+package cmd
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	defaultBinaryPath  = "/usr/local/bin/go-alived"
+	defaultConfigDir   = "/etc/go-alived"
+	defaultConfigFile  = "/etc/go-alived/config.yaml"
+	systemdServicePath = "/etc/systemd/system/go-alived.service"
+	initdScriptPath    = "/etc/init.d/go-alived"
+)
+
+var (
+	installMethod string
+)
+
+var installCmd = &cobra.Command{
+	Use:     "install",
+	Aliases: []string{"i"},
+	Short:   "Install go-alived as a system service",
+	Long: `Install go-alived binary and configuration files to system paths.
+
+Supported installation methods:
+  - systemd: Install as a systemd service (default, recommended for modern Linux)
+  - service: Install as a SysV init.d service (for older Linux distributions)
+
+Examples:
+  sudo go-alived install
+  sudo go-alived install --method systemd
+  sudo go-alived i -m service`,
+	Run: runInstall,
+}
+
+func init() {
+	rootCmd.AddCommand(installCmd)
+
+	installCmd.Flags().StringVarP(&installMethod, "method", "m", "systemd",
+		"installation method: systemd, service")
+}
+
+func runInstall(cmd *cobra.Command, args []string) {
+	// Check root privileges
+	if os.Geteuid() != 0 {
+		fmt.Println("Error: This command requires root privileges")
+		fmt.Println("Please run with: sudo go-alived install")
+		os.Exit(1)
+	}
+
+	// Validate method
+	method := strings.ToLower(installMethod)
+	if method != "systemd" && method != "service" {
+		fmt.Printf("Error: Invalid installation method '%s'\n", installMethod)
+		fmt.Println("Supported methods: systemd, service")
+		os.Exit(1)
+	}
+
+	fmt.Println("=== Go-Alived Installation ===")
+	fmt.Println()
+
+	const totalSteps = 3
+
+	// Step 1: Copy binary
+	if err := installBinary(1, totalSteps); err != nil {
+		fmt.Printf("Error installing binary: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Step 2: Create config directory and file
+	configCreated, err := installConfig(2, totalSteps)
+	if err != nil {
+		fmt.Printf("Error installing config: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Step 3: Install service script
+	if err := installServiceScript(3, totalSteps, method); err != nil {
+		fmt.Printf("Error installing service script: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Print completion message
+	printCompletionMessage(method, configCreated)
+}
+
+func installBinary(step, total int) error {
+	fmt.Printf("[%d/%d] Installing binary... ", step, total)
+
+	// Get current executable path
+	execPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("failed to get executable path: %w", err)
+	}
+
+	// Resolve symlinks
+	execPath, err = filepath.EvalSymlinks(execPath)
+	if err != nil {
+		return fmt.Errorf("failed to resolve symlinks: %w", err)
+	}
+
+	// Check if already installed at target path
+	if execPath == defaultBinaryPath {
+		fmt.Println("already installed")
+		return nil
+	}
+
+	// Open source file
+	src, err := os.Open(execPath)
+	if err != nil {
+		return fmt.Errorf("failed to open source binary: %w", err)
+	}
+	defer src.Close()
+
+	// Create destination file
+	dst, err := os.OpenFile(defaultBinaryPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)
+	if err != nil {
+		return fmt.Errorf("failed to create destination binary: %w", err)
+	}
+	defer dst.Close()
+
+	// Copy binary
+	if _, err := io.Copy(dst, src); err != nil {
+		return fmt.Errorf("failed to copy binary: %w", err)
+	}
+
+	fmt.Printf("done (%s)\n", defaultBinaryPath)
+	return nil
+}
+
+func installConfig(step, total int) (bool, error) {
+	fmt.Printf("[%d/%d] Setting up configuration... ", step, total)
+
+	// Create config directory
+	if err := os.MkdirAll(defaultConfigDir, 0755); err != nil {
+		return false, fmt.Errorf("failed to create config directory: %w", err)
+	}
+
+	// Check if config file already exists
+	if _, err := os.Stat(defaultConfigFile); err == nil {
+		fmt.Println("config already exists")
+		return false, nil
+	}
+
+	// Generate config content
+	configContent := generateDefaultConfig()
+
+	// Write config file
+	if err := os.WriteFile(defaultConfigFile, []byte(configContent), 0644); err != nil {
+		return false, fmt.Errorf("failed to write config file: %w", err)
+	}
+
+	fmt.Printf("done (%s)\n", defaultConfigFile)
+	return true, nil
+}
+
+func installServiceScript(step, total int, method string) error {
+	switch method {
+	case "systemd":
+		return installSystemdService(step, total)
+	case "service":
+		return installInitdScript(step, total)
+	default:
+		return fmt.Errorf("unsupported method: %s", method)
+	}
+}
+
+func installSystemdService(step, total int) error {
+	fmt.Printf("[%d/%d] Installing systemd service... ", step, total)
+
+	serviceContent := generateSystemdService()
+
+	if err := os.WriteFile(systemdServicePath, []byte(serviceContent), 0644); err != nil {
+		return fmt.Errorf("failed to write service file: %w", err)
+	}
+
+	fmt.Printf("done (%s)\n", systemdServicePath)
+	return nil
+}
+
+func installInitdScript(step, total int) error {
+	fmt.Printf("[%d/%d] Installing init.d script... ", step, total)
+
+	scriptContent := generateInitdScript()
+
+	if err := os.WriteFile(initdScriptPath, []byte(scriptContent), 0755); err != nil {
+		return fmt.Errorf("failed to write init.d script: %w", err)
+	}
+
+	fmt.Printf("done (%s)\n", initdScriptPath)
+	return nil
+}
+
+func generateDefaultConfig() string {
+	// Auto-detect network interface
+	iface := detectNetworkInterface()
+	hostname, _ := os.Hostname()
+	if hostname == "" {
+		hostname = "node1"
+	}
+
+	return fmt.Sprintf(`# Go-Alived Configuration
+# Generated by: go-alived install
+# Documentation: https://github.com/loveuer/go-alived
+
+global:
+  router_id: "%s"
+
+vrrp_instances:
+  - name: "VI_1"
+    interface: "%s"
+    state: "BACKUP"
+    virtual_router_id: 51
+    priority: 100
+    advert_interval: 1
+    auth_type: "PASS"
+    auth_pass: "changeme"    # TODO: Change this password
+    virtual_ips:
+      - "192.168.1.100/24"   # TODO: Change to your VIP
+
+# Optional: Health checkers
+# health_checkers:
+#   - name: "check_nginx"
+#     type: "tcp"
+#     interval: 3s
+#     timeout: 2s
+#     rise: 3
+#     fall: 2
+#     config:
+#       host: "127.0.0.1"
+#       port: 80
+`, hostname, iface)
+}
+
+func generateSystemdService() string {
+	return `[Unit]
+Description=Go-Alived - VRRP High Availability Service
+Documentation=https://github.com/loveuer/go-alived
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=root
+Group=root
+
+ExecStart=/usr/local/bin/go-alived run --config /etc/go-alived/config.yaml
+ExecReload=/bin/kill -HUP $MAINPID
+
+Restart=on-failure
+RestartSec=5s
+
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=go-alived
+
+# Security settings
+NoNewPrivileges=false
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/etc/go-alived
+
+# Resource limits
+LimitNOFILE=65535
+LimitNPROC=512
+
+# Capabilities required for VRRP operations
+AmbientCapabilities=CAP_NET_ADMIN CAP_NET_RAW CAP_NET_BIND_SERVICE
+CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_RAW CAP_NET_BIND_SERVICE
+
+[Install]
+WantedBy=multi-user.target
+`
+}
+
+func generateInitdScript() string {
+	return `#!/bin/sh
+### BEGIN INIT INFO
+# Provides:          go-alived
+# Required-Start:    $network $remote_fs $syslog
+# Required-Stop:     $network $remote_fs $syslog
+# Default-Start:     2 3 4 5
+# Default-Stop:      0 1 6
+# Short-Description: Go-Alived VRRP High Availability Service
+# Description:       Lightweight VRRP implementation for IP high availability
+### END INIT INFO
+
+NAME="go-alived"
+DAEMON="/usr/local/bin/go-alived"
+DAEMON_ARGS="run --config /etc/go-alived/config.yaml"
+PIDFILE="/var/run/${NAME}.pid"
+LOGFILE="/var/log/${NAME}.log"
+
+[ -x "$DAEMON" ] || exit 5
+
+start() {
+    if [ -f "$PIDFILE" ] && kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
+        echo "$NAME is already running"
+        return 1
+    fi
+    echo -n "Starting $NAME... "
+    nohup $DAEMON $DAEMON_ARGS >> "$LOGFILE" 2>&1 &
+    echo $! > "$PIDFILE"
+    echo "done (PID: $(cat "$PIDFILE"))"
+}
+
+stop() {
+    if [ ! -f "$PIDFILE" ] || ! kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
+        echo "$NAME is not running"
+        return 1
+    fi
+    echo -n "Stopping $NAME... "
+    kill "$(cat "$PIDFILE")"
+    rm -f "$PIDFILE"
+    echo "done"
+}
+
+restart() {
+    stop
+    sleep 1
+    start
+}
+
+reload() {
+    if [ ! -f "$PIDFILE" ] || ! kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
+        echo "$NAME is not running"
+        return 1
+    fi
+    echo -n "Reloading $NAME configuration... "
+    kill -HUP "$(cat "$PIDFILE")"
+    echo "done"
+}
+
+status() {
+    if [ -f "$PIDFILE" ] && kill -0 "$(cat "$PIDFILE")" 2>/dev/null; then
+        echo "$NAME is running (PID: $(cat "$PIDFILE"))"
+    else
+        echo "$NAME is not running"
+        [ -f "$PIDFILE" ] && rm -f "$PIDFILE"
+        return 1
+    fi
+}
+
+case "$1" in
+    start)   start   ;;
+    stop)    stop    ;;
+    restart) restart ;;
+    reload)  reload  ;;
+    status)  status  ;;
+    *)
+        echo "Usage: $0 {start|stop|restart|reload|status}"
+        exit 2
+        ;;
+esac
+
+exit $?
+`
+}
+
+func detectNetworkInterface() string {
+	interfaces, err := net.Interfaces()
+	if err != nil {
+		return "eth0"
+	}
+
+	for _, iface := range interfaces {
+		// Skip loopback and down interfaces
+		if iface.Flags&net.FlagLoopback != 0 {
+			continue
+		}
+		if iface.Flags&net.FlagUp == 0 {
+			continue
+		}
+
+		// Check if interface has IPv4 address
+		addrs, err := iface.Addrs()
+		if err != nil {
+			continue
+		}
+
+		for _, addr := range addrs {
+			if ipNet, ok := addr.(*net.IPNet); ok {
+				if ipv4 := ipNet.IP.To4(); ipv4 != nil && !ipv4.IsLoopback() {
+					return iface.Name
+				}
+			}
+		}
+	}
+
+	return "eth0"
+}
+
+func printCompletionMessage(method string, configCreated bool) {
+	fmt.Println()
+	fmt.Println("=== Installation Complete ===")
+	fmt.Println()
+
+	// Installed files summary
+	fmt.Println(">>> Installed Files:")
+	fmt.Printf("    Binary:  %s\n", defaultBinaryPath)
+	fmt.Printf("    Config:  %s\n", defaultConfigFile)
+	if method == "systemd" {
+		fmt.Printf("    Service: %s\n", systemdServicePath)
+	} else {
+		fmt.Printf("    Service: %s\n", initdScriptPath)
+	}
+	fmt.Println()
+
+	// What needs to be modified
+	fmt.Println(">>> Configuration Required:")
+	fmt.Printf("    Edit: %s\n", defaultConfigFile)
+	fmt.Println()
+	if configCreated {
+		fmt.Println("    Modify the following settings:")
+		fmt.Println("    - auth_pass:    Change 'changeme' to a secure password")
+		fmt.Println("    - virtual_ips:  Set your Virtual IP address(es)")
+		fmt.Println("    - interface:    Verify the network interface is correct")
+		fmt.Println("    - priority:     Adjust based on node role (higher = more likely master)")
+	} else {
+		fmt.Println("    Review your existing configuration")
+	}
+	fmt.Println()
+
+	// How to start
+	fmt.Println(">>> Next Steps:")
+	if method == "systemd" {
+		fmt.Println("    1. Edit configuration:")
+		fmt.Printf("       sudo vim %s\n", defaultConfigFile)
+		fmt.Println()
+		fmt.Println("    2. Reload systemd and start service:")
+		fmt.Println("       sudo systemctl daemon-reload")
+		fmt.Println("       sudo systemctl enable go-alived")
+		fmt.Println("       sudo systemctl start go-alived")
+		fmt.Println()
+		fmt.Println("    3. Check service status:")
+		fmt.Println("       sudo systemctl status go-alived")
+		fmt.Println("       sudo journalctl -u go-alived -f")
+	} else {
+		fmt.Println("    1. Edit configuration:")
+		fmt.Printf("       sudo vim %s\n", defaultConfigFile)
+		fmt.Println()
+		fmt.Println("    2. Start service:")
+		fmt.Printf("       sudo %s start\n", initdScriptPath)
+		fmt.Println()
+		fmt.Println("    3. Enable on boot (Debian/Ubuntu):")
+		fmt.Println("       sudo update-rc.d go-alived defaults")
+		fmt.Println()
+		fmt.Println("    4. Check service status:")
+		fmt.Printf("       sudo %s status\n", initdScriptPath)
+		fmt.Printf("       tail -f /var/log/go-alived.log\n")
+	}
+	fmt.Println()
+
+	// Test environment
+	fmt.Println(">>> Test Environment (Optional):")
+	fmt.Printf("    sudo %s test\n", defaultBinaryPath)
+	fmt.Println()
+}

internal/cmd/root.go

@@ -6,12 +6,14 @@ import (
 	"github.com/spf13/cobra"
 )
 
+// Version can be set at build time via ldflags
+var Version = "1.3.0"
+
 var rootCmd = &cobra.Command{
 	Use:   "go-alived",
 	Short: "Go-Alived - VRRP High Availability Service",
 	Long: `go-alived is a lightweight, dependency-free VRRP implementation in Go.
 It provides high availability for IP addresses with health checking support.`,
-	Version: "1.0.0",
 }
 
 func Execute() {
@@ -21,5 +23,6 @@ func Execute() {
 }
 
 func init() {
+	rootCmd.Version = Version
 	rootCmd.CompletionOptions.DisableDefaultCmd = true
 }

internal/cmd/run.go

@@ -58,6 +58,7 @@ func runService(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 
+	setupNotifyScripts(vrrpMgr, cfg, log)
 	setupHealthTracking(vrrpMgr, healthMgr, log)
 
 	healthMgr.StartAll()
@@ -100,6 +101,27 @@ func cleanup(log *logger.Logger, vrrpMgr *vrrp.Manager, healthMgr *health.Manage
 	vrrpMgr.StopAll()
 }
 
+func setupNotifyScripts(vrrpMgr *vrrp.Manager, cfg *config.Config, log *logger.Logger) {
+	for _, vrrpCfg := range cfg.VRRP {
+		if vrrpCfg.NotifyMaster == "" && vrrpCfg.NotifyBackup == "" && vrrpCfg.NotifyFault == "" {
+			continue
+		}
+
+		inst, ok := vrrpMgr.GetInstance(vrrpCfg.Name)
+		if !ok {
+			continue
+		}
+
+		vrrp.SetupNotify(inst, &vrrp.NotifyConfig{
+			Name:         vrrpCfg.Name,
+			NotifyMaster: vrrpCfg.NotifyMaster,
+			NotifyBackup: vrrpCfg.NotifyBackup,
+			NotifyFault:  vrrpCfg.NotifyFault,
+			Log:          log,
+		})
+	}
+}
+
 func setupHealthTracking(vrrpMgr *vrrp.Manager, healthMgr *health.Manager, log *logger.Logger) {
 	instances := vrrpMgr.GetAllInstances()
 

internal/vrrp/notify.go

@@ -0,0 +1,89 @@
+package vrrp
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+
+	"github.com/loveuer/go-alived/pkg/logger"
+)
+
+const notifyTimeout = 60 * time.Second
+
+// NotifyConfig holds the notify script configuration for a VRRP instance.
+type NotifyConfig struct {
+	Name          string
+	NotifyMaster  string
+	NotifyBackup  string
+	NotifyFault   string
+	Log           *logger.Logger
+}
+
+// SetupNotify registers notify scripts as state change callbacks on the instance.
+func SetupNotify(inst *Instance, cfg *NotifyConfig) {
+	if cfg.NotifyMaster != "" {
+		script := cfg.NotifyMaster
+		inst.OnMaster(func() {
+			cfg.Log.Info("[%s] executing notify_master script", cfg.Name)
+			go runNotifyScript(cfg.Log, cfg.Name, "notify_master", script)
+		})
+		cfg.Log.Info("[%s] registered notify_master script", cfg.Name)
+	}
+
+	if cfg.NotifyBackup != "" {
+		script := cfg.NotifyBackup
+		inst.OnBackup(func() {
+			cfg.Log.Info("[%s] executing notify_backup script", cfg.Name)
+			go runNotifyScript(cfg.Log, cfg.Name, "notify_backup", script)
+		})
+		cfg.Log.Info("[%s] registered notify_backup script", cfg.Name)
+	}
+
+	if cfg.NotifyFault != "" {
+		script := cfg.NotifyFault
+		inst.OnFault(func() {
+			cfg.Log.Info("[%s] executing notify_fault script", cfg.Name)
+			go runNotifyScript(cfg.Log, cfg.Name, "notify_fault", script)
+		})
+		cfg.Log.Info("[%s] registered notify_fault script", cfg.Name)
+	}
+}
+
+func runNotifyScript(log *logger.Logger, instName, event, script string) {
+	ctx, cancel := context.WithTimeout(context.Background(), notifyTimeout)
+	defer cancel()
+
+	cmd := buildCommand(ctx, script)
+	cmd.Env = append(os.Environ(),
+		fmt.Sprintf("GO_ALIVED_INSTANCE=%s", instName),
+		fmt.Sprintf("GO_ALIVED_EVENT=%s", event),
+	)
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Error("[%s] %s script failed: %v (output: %s)",
+			instName, event, err, strings.TrimSpace(string(output)))
+		return
+	}
+
+	if len(output) > 0 {
+		log.Info("[%s] %s script output: %s",
+			instName, event, strings.TrimSpace(string(output)))
+	}
+	log.Info("[%s] %s script completed successfully", instName, event)
+}
+
+func buildCommand(ctx context.Context, script string) *exec.Cmd {
+	script = strings.TrimSpace(script)
+
+	// If the script is a path to an existing executable file, run it directly
+	if info, err := os.Stat(script); err == nil && !info.IsDir() {
+		return exec.CommandContext(ctx, script)
+	}
+
+	// Otherwise treat as inline shell script
+	return exec.CommandContext(ctx, "sh", "-c", script)
+}