2 Commits

Author SHA1 Message Date
Ben Roberts
256afcbd97 Add configuration option to select iptables implementation
When running gocast in a container, the default iptables implementation
may not match that used on the underlying host kernel. The current
container uses the legacy iptables implementation and calls the
`iptables` binary. This fails with exit code 3 when running on a host
using the newer nftables implementation. The container already has
`iptables-nft` binary included, so just needs a way to call this instead
of the default `iptables` binary.

This change implements a new `iptables_binary` config option, defaulting
to `iptables`, and calls this when adding or removing NAT rules.

Fixes #32

This change was written using AI LLM.

Authored-By: Claude Code (Sonnet 4.5)
2026-06-17 17:18:59 +01:00
Ben Roberts
fe399e2f03 Support for reloading config file on HUP signal
Implemented dynamic configuration reloading for gocast via SIGHUP signal handling. This allows updating BGP configuration, applications, and agent settings without service restart.

**Location:** `main.go:29-46`

Enhanced the existing signal handler to process SIGHUP:
```go
switch sig {
case syscall.SIGHUP:
    log.Info("Received SIGHUP, reloading configuration")
    if err := mon.Reload(*config); err != nil {
        log.Errorf("Failed to reload configuration: %v", err)
    } else {
        log.Info("Configuration reloaded successfully")
    }
case os.Interrupt, syscall.SIGTERM:
    log.Info("Received shutdown signal, cleaning up")
    mon.CloseAll()
    cancel()
    return
}
```

**Key Features:**
- Non-blocking: Uses goroutine to handle signals
- Graceful: SIGINT/SIGTERM still trigger clean shutdown
- Logged: All reload attempts are logged with success/failure status

**Location:** `controller/monitor.go:343-420`

Main reload orchestration method:

```go
func (m *MonitorMgr) Reload(configPath string) error
```

**Process Flow:**
1. Read new configuration from file
2. Compare with current configuration
3. If BGP config changed:
   - Withdraw all announced routes
   - Shutdown old BGP controller
   - Start new BGP controller
   - Re-announce routes for healthy apps
4. If Consul config changed:
   - Initialize new Consul monitor
5. Update agent settings
6. Reload applications (add/remove/update)

**Thread Safety:**
- Uses existing `monMu` mutex for monitor map access
- Atomic BGP controller replacement
- No race conditions during reload

**Location:** `controller/monitor.go:422-475`

```go
func (m *MonitorMgr) bgpConfigChanged(old, new c.BgpConfig) bool
```

Comprehensive comparison of:
- Local AS, Peer AS, Peer IPs
- BGP origin
- Multi-hop settings (including nil checks)
- MD5 passwords and environment variables
- Per-peer communities
- Global communities

**Important:** Deep comparison ensures even minor changes are detected.

**Location:** `controller/monitor.go:477-532`

```go
func (m *MonitorMgr) reloadApps(oldApps, newApps []c.AppConfig)
```

Intelligent app management:
- **Remove:** Apps no longer in config (source="config" only)
- **Update:** Apps with changed configuration (VIP, monitors, NAT, communities)
- **Add:** New apps in configuration

**Key Behavior:**
- Consul-discovered apps are NOT removed during reload
- Only config-defined apps are managed
- Config changes trigger remove + re-add

1. **TestBgpConfigChanged**
   - Tests all BGP configuration change scenarios
   - Validates detection of AS, peer, MD5, community changes
   - Includes nil multi-hop pointer checks

2. **TestEqualStringSlices**
   - Tests slice comparison helper
   - Validates empty, identical, and different slices

3. **TestReload** (Integration, requires root)
   - Full reload cycle with BGP AS change
   - App removal verification
   - BGP controller replacement validation

4. **TestReloadAddApp** (Integration)
   - Tests adding new app via reload
   - Validates app registration

5. **TestReloadMD5Change** (Integration)
   - Tests MD5 password change detection
   - Validates BGP controller restart

**Decision:** Reload BGP configuration requires full controller restart.

**Rationale:**
- GoBGP library doesn't support modifying peers dynamically
- Simplifies implementation
- Ensures clean state
- Brief interruption is acceptable for infrequent config changes

**Alternative Considered:** Per-peer updates
- Complex to implement correctly
- Partial state issues
- Not supported well by GoBGP library

**Decision:** Log errors but don't crash; maintain old state on failure.

**Rationale:**
- Availability over correctness for config errors
- Admin can fix config and retry
- Better than service downtime
- Logs provide clear error messages

1. **BGP Interruption**
   - Full BGP restart causes brief routing interruption
   - All routes withdrawn and re-announced
   - May impact traffic during reload

2. **No Atomic BGP Updates**
   - Cannot add/remove single peer without full restart
   - All peers affected even if one changes

3. **No Config Validation**
   - Invalid config is detected during reload
   - No pre-validation before applying
   - Syntax errors require manual fix and retry

4. **No Rollback**
   - Failed reload leaves service in potentially inconsistent state
   - Manual intervention required to restore
   - No automatic rollback to previous config

These changes were written using AI LLM

Authored-By: Claude Code (Sonnet 4.5)
2026-06-17 16:52:03 +01:00
8 changed files with 647 additions and 4 deletions

View File

@@ -63,6 +63,31 @@ Alternatively, if `gocast_nat=protocol:port` is specified, then GoCast will crea
Example: `gocast_nat=tcp:53` and `gocast_nat=udp:53` Example: `gocast_nat=tcp:53` and `gocast_nat=udp:53`
## Configuration Reload
GoCast supports dynamic configuration reloading without service restart. Send a `SIGHUP` signal to reload the configuration:
```bash
kill -HUP $(pidof gocast)
```
**What gets reloaded:**
- BGP configuration (peers, AS numbers, MD5 passwords, communities)
- Application definitions (add/remove/update apps)
- Agent settings (Consul, timers, intervals, iptables binary)
**Important:** Reloading BGP configuration causes existing BGP sessions to be restarted, resulting in brief routing interruption. Routes are automatically re-announced after reload.
Consul-discovered apps are not removed during reload.
## Iptables Configuration
On modern Linux systems using nftables, you need to configure gocast to use `iptables-nft` instead of the legacy `iptables` binary (default):
```yaml
agent:
iptables_binary: iptables-nft
```
## Docker support ## Docker support
The docker image at mayuresh82/gocast can be used to run GoCast inside a container. In order for GoCast to manipulate the host network stack correctly, the container needs to run with NET_ADMIN capablity and host mode networking. For example: The docker image at mayuresh82/gocast can be used to run GoCast inside a container. In order for GoCast to manipulate the host network stack correctly, the container needs to run with NET_ADMIN capablity and host mode networking. For example:
``` ```

View File

@@ -11,6 +11,9 @@ agent:
consul_query_interval: 5m consul_query_interval: 5m
# token to authenticate client if consul requires it # token to authenticate client if consul requires it
consul_token: 00000000-0000-0000-0000-000000000000 consul_token: 00000000-0000-0000-0000-000000000000
# iptables binary to use for NAT rules (default: iptables)
# Use "iptables-nft" on modern systems with nftables
# iptables_binary: iptables-nft
bgp: bgp:
local_as: 12345 local_as: 12345

View File

@@ -16,6 +16,7 @@ type AgentConfig struct {
ConsulAddr string `yaml:"consul_addr"` ConsulAddr string `yaml:"consul_addr"`
ConsulQueryInterval time.Duration `yaml:"consul_query_interval"` ConsulQueryInterval time.Duration `yaml:"consul_query_interval"`
ConsulToken string `yaml:"consul_token"` ConsulToken string `yaml:"consul_token"`
IptablesBinary string `yaml:"iptables_binary"`
} }
type PeerConfig struct { type PeerConfig struct {

View File

@@ -98,6 +98,11 @@ func NewMonitor(config *c.Config) *MonitorMgr {
if config.Agent.CleanupTimer == 0 { if config.Agent.CleanupTimer == 0 {
config.Agent.CleanupTimer = defaultCleanupTimer config.Agent.CleanupTimer = defaultCleanupTimer
} }
// Set iptables binary (defaults to "iptables" if not specified)
if config.Agent.IptablesBinary == "" {
config.Agent.IptablesBinary = "iptables"
}
SetIptablesBinary(config.Agent.IptablesBinary)
mon.config = config mon.config = config
// add apps defined in config // add apps defined in config
for _, a := range config.Apps { for _, a := range config.Apps {
@@ -339,6 +344,240 @@ func (m *MonitorMgr) CloseAll() {
} }
} }
// Reload re-reads the configuration file and applies changes
func (m *MonitorMgr) Reload(configPath string) error {
glog.Infof("Reloading configuration from %s", configPath)
// Read new configuration
newConfig := c.GetConfig(configPath)
if newConfig == nil {
return fmt.Errorf("Failed to load configuration")
}
// Set defaults if not specified
if newConfig.Agent.MonitorInterval == 0 {
newConfig.Agent.MonitorInterval = defaultMonitorInterval
}
if newConfig.Agent.CleanupTimer == 0 {
newConfig.Agent.CleanupTimer = defaultCleanupTimer
}
if newConfig.Agent.IptablesBinary == "" {
newConfig.Agent.IptablesBinary = "iptables"
}
// Update iptables binary if changed
if m.config.Agent.IptablesBinary != newConfig.Agent.IptablesBinary {
glog.Infof("Iptables binary changed from %s to %s", m.config.Agent.IptablesBinary, newConfig.Agent.IptablesBinary)
SetIptablesBinary(newConfig.Agent.IptablesBinary)
}
// Check if BGP configuration has changed
bgpChanged := m.bgpConfigChanged(m.config.Bgp, newConfig.Bgp)
if bgpChanged {
glog.Infof("BGP configuration changed, restarting BGP controller")
// Withdraw all current routes before shutting down
m.monMu.Lock()
for _, am := range m.monitors {
if am.announced {
if err := m.ctrl.Withdraw(am.app.Vip); err != nil {
glog.Errorf("Failed to withdraw route during reload: %v", err)
}
am.announced = false
}
}
m.monMu.Unlock()
// Shutdown old BGP controller
if err := m.ctrl.Shutdown(); err != nil {
glog.Errorf("Failed to shutdown BGP controller: %v", err)
}
// Start new BGP controller
ctrl, err := NewController(newConfig.Bgp)
if err != nil {
return fmt.Errorf("Failed to start new BGP controller: %v", err)
}
m.ctrl = ctrl
// Re-announce all routes with new BGP config
m.monMu.Lock()
for _, am := range m.monitors {
// Only re-announce if the app was previously announced and is still healthy
if m.runMonitors(am.app) {
if err := m.ctrl.Announce(am.app.Vip); err != nil {
glog.Errorf("Failed to re-announce route %s: %v", am.app.Vip.Net.String(), err)
} else {
am.announced = true
glog.Infof("Re-announced route %s", am.app.Vip.Net.String())
}
}
}
m.monMu.Unlock()
}
// Handle consul configuration changes
if m.config.Agent.ConsulAddr != newConfig.Agent.ConsulAddr ||
m.config.Agent.ConsulToken != newConfig.Agent.ConsulToken {
glog.Infof("Consul configuration changed")
if newConfig.Agent.ConsulAddr != "" {
cmon, err := NewConsulMon(newConfig.Agent.ConsulAddr, newConfig.Agent.ConsulToken)
if err != nil {
glog.Errorf("Failed to start consul monitor: %v", err)
} else {
m.consul = cmon
// Start consul monitoring in background if not already running
if m.config.Agent.ConsulAddr == "" {
go m.consulMon()
}
}
}
}
// Update agent configuration
oldConfig := m.config
m.config = newConfig
// Handle app configuration changes
m.reloadApps(oldConfig.Apps, newConfig.Apps)
glog.Infof("Configuration reloaded successfully")
return nil
}
// bgpConfigChanged checks if BGP configuration has changed
func (m *MonitorMgr) bgpConfigChanged(old, new c.BgpConfig) bool {
// Check basic parameters
if old.LocalAS != new.LocalAS || old.LocalIP != new.LocalIP || old.Origin != new.Origin {
return true
}
// Check legacy peer config
if old.PeerAS != new.PeerAS || old.PeerIP != new.PeerIP {
return true
}
// Check peers
if len(old.Peers) != len(new.Peers) {
return true
}
// Compare each peer
for i := range old.Peers {
if old.Peers[i].PeerIP != new.Peers[i].PeerIP ||
old.Peers[i].PeerAS != new.Peers[i].PeerAS ||
old.Peers[i].MD5Password != new.Peers[i].MD5Password ||
old.Peers[i].MD5EnvVar != new.Peers[i].MD5EnvVar {
return true
}
// Check multi-hop
if (old.Peers[i].MultiHop == nil) != (new.Peers[i].MultiHop == nil) {
return true
}
if old.Peers[i].MultiHop != nil && new.Peers[i].MultiHop != nil {
if *old.Peers[i].MultiHop != *new.Peers[i].MultiHop {
return true
}
}
// Check communities
if len(old.Peers[i].Communities) != len(new.Peers[i].Communities) {
return true
}
for j := range old.Peers[i].Communities {
if old.Peers[i].Communities[j] != new.Peers[i].Communities[j] {
return true
}
}
}
// Check global communities
if len(old.Communities) != len(new.Communities) {
return true
}
for i := range old.Communities {
if old.Communities[i] != new.Communities[i] {
return true
}
}
return false
}
// reloadApps compares old and new app configurations and applies changes
func (m *MonitorMgr) reloadApps(oldApps, newApps []c.AppConfig) {
// Build maps for easy comparison
oldAppMap := make(map[string]c.AppConfig)
for _, app := range oldApps {
oldAppMap[app.Name] = app
}
newAppMap := make(map[string]c.AppConfig)
for _, app := range newApps {
newAppMap[app.Name] = app
}
// Remove apps that are no longer in config
for name := range oldAppMap {
if _, exists := newAppMap[name]; !exists {
m.monMu.Lock()
if am, ok := m.monitors[name]; ok {
if am.app.Source == "config" {
glog.Infof("Removing app %s (no longer in config)", name)
m.monMu.Unlock()
m.Remove(name)
continue
}
}
m.monMu.Unlock()
}
}
// Add new apps or update existing ones
for name, newAppConfig := range newAppMap {
oldAppConfig, existed := oldAppMap[name]
// Check if app configuration changed
configChanged := !existed ||
oldAppConfig.Vip != newAppConfig.Vip ||
!equalStringSlices(oldAppConfig.Monitors, newAppConfig.Monitors) ||
!equalStringSlices(oldAppConfig.Nats, newAppConfig.Nats) ||
!equalStringSlices(oldAppConfig.VipConfig.BgpCommunities, newAppConfig.VipConfig.BgpCommunities)
if configChanged {
if existed {
glog.Infof("App %s configuration changed, reloading", name)
m.Remove(name)
} else {
glog.Infof("Adding new app %s from config", name)
}
app, err := NewApp(newAppConfig.Name, newAppConfig.Vip, newAppConfig.VipConfig,
newAppConfig.Monitors, newAppConfig.Nats, "config")
if err != nil {
glog.Errorf("Failed to add app %s: %v", name, err)
continue
}
m.Add(app)
}
}
}
// equalStringSlices compares two string slices
func equalStringSlices(a, b []string) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if a[i] != b[i] {
return false
}
}
return true
}
// CleanUp periodically monitors for stale apps and cleans them up // CleanUp periodically monitors for stale apps and cleans them up
func (m *MonitorMgr) Cleanup(app string, exit chan bool) { func (m *MonitorMgr) Cleanup(app string, exit chan bool) {
t := time.NewTimer(m.config.Agent.CleanupTimer) t := time.NewTimer(m.config.Agent.CleanupTimer)

293
controller/reload_test.go Normal file
View File

@@ -0,0 +1,293 @@
package controller
import (
"io/ioutil"
"os"
"testing"
"time"
config "github.com/mayuresh82/gocast/config"
"github.com/stretchr/testify/assert"
)
func TestBgpConfigChanged(t *testing.T) {
a := assert.New(t)
mon := &MonitorMgr{}
// Test 1: No changes
cfg1 := config.BgpConfig{
LocalAS: 12345,
LocalIP: "192.168.1.100",
Origin: "igp",
Peers: []config.PeerConfig{
{PeerIP: "10.10.10.1", PeerAS: 6789},
},
Communities: []string{"100:100"},
}
cfg2 := cfg1
a.False(mon.bgpConfigChanged(cfg1, cfg2), "Identical configs should not be considered changed")
// Test 2: LocalAS changed
cfg3 := cfg1
cfg3.LocalAS = 54321
a.True(mon.bgpConfigChanged(cfg1, cfg3), "LocalAS change should be detected")
// Test 3: Peer IP changed
cfg4 := cfg1
cfg4.Peers = []config.PeerConfig{
{PeerIP: "10.10.10.2", PeerAS: 6789},
}
a.True(mon.bgpConfigChanged(cfg1, cfg4), "Peer IP change should be detected")
// Test 4: MD5 password changed
cfg5 := cfg1
cfg5.Peers = []config.PeerConfig{
{PeerIP: "10.10.10.1", PeerAS: 6789, MD5Password: "secret"},
}
a.True(mon.bgpConfigChanged(cfg1, cfg5), "MD5 password change should be detected")
// Test 5: Community added
cfg6 := cfg1
cfg6.Communities = []string{"100:100", "200:200"}
a.True(mon.bgpConfigChanged(cfg1, cfg6), "Community addition should be detected")
// Test 6: Peer added
cfg7 := cfg1
cfg7.Peers = []config.PeerConfig{
{PeerIP: "10.10.10.1", PeerAS: 6789},
{PeerIP: "10.10.10.2", PeerAS: 6789},
}
a.True(mon.bgpConfigChanged(cfg1, cfg7), "Peer addition should be detected")
// Test 7: MultiHop changed
multiHopTrue := true
cfg8 := cfg1
cfg8.Peers = []config.PeerConfig{
{PeerIP: "10.10.10.1", PeerAS: 6789, MultiHop: &multiHopTrue},
}
a.True(mon.bgpConfigChanged(cfg1, cfg8), "MultiHop change should be detected")
}
func TestEqualStringSlices(t *testing.T) {
a := assert.New(t)
a.True(equalStringSlices([]string{}, []string{}), "Empty slices should be equal")
a.True(equalStringSlices([]string{"a", "b"}, []string{"a", "b"}), "Identical slices should be equal")
a.False(equalStringSlices([]string{"a"}, []string{"a", "b"}), "Different length slices should not be equal")
a.False(equalStringSlices([]string{"a", "b"}, []string{"a", "c"}), "Different content should not be equal")
}
func TestReload(t *testing.T) {
if os.Getenv("CI") != "" {
t.Skip("Skipping reload test in CI environment")
}
a := assert.New(t)
// Create initial config file
initialConfig := `
agent:
listen_addr: :8080
monitor_interval: 10s
cleanup_timer: 15m
bgp:
local_as: 12345
peer_as: 6789
local_ip: 192.168.1.100
origin: igp
communities:
- 100:100
apps:
- name: test-app
vip: 1.1.1.1/32
monitors:
- exec:echo
`
// Create temporary config file
tmpfile, err := ioutil.TempFile("", "gocast-test-*.yaml")
a.NoError(err)
defer os.Remove(tmpfile.Name())
_, err = tmpfile.Write([]byte(initialConfig))
a.NoError(err)
tmpfile.Close()
// Initialize monitor with initial config
conf := config.GetConfig(tmpfile.Name())
mon := NewMonitor(conf)
defer mon.CloseAll()
// Wait a bit for initialization
time.Sleep(100 * time.Millisecond)
// Verify initial state
a.Equal(12345, mon.ctrl.localAS)
m := mon.monitors["test-app"]
a.NotNil(m, "Initial app should be loaded")
// Update config file with new BGP AS and remove app
updatedConfig := `
agent:
listen_addr: :8080
monitor_interval: 10s
cleanup_timer: 15m
bgp:
local_as: 54321
peer_as: 6789
local_ip: 192.168.1.100
origin: igp
communities:
- 200:200
`
err = ioutil.WriteFile(tmpfile.Name(), []byte(updatedConfig), 0644)
a.NoError(err)
// Reload configuration
err = mon.Reload(tmpfile.Name())
a.NoError(err)
// Wait for reload to complete
time.Sleep(200 * time.Millisecond)
// Verify new state
a.Equal(54321, mon.ctrl.localAS)
a.Equal([]string{"200:200"}, mon.ctrl.communities)
// Verify app was removed
mon.monMu.Lock()
_, exists := mon.monitors["test-app"]
mon.monMu.Unlock()
a.False(exists, "App should be removed after reload")
}
func TestReloadAddApp(t *testing.T) {
if os.Getenv("CI") != "" {
t.Skip("Skipping reload test in CI environment")
}
a := assert.New(t)
// Create initial config without apps
initialConfig := `
agent:
listen_addr: :8080
monitor_interval: 10s
bgp:
local_as: 12345
peer_as: 6789
local_ip: 192.168.1.100
origin: igp
`
tmpfile, err := ioutil.TempFile("", "gocast-test-*.yaml")
a.NoError(err)
defer os.Remove(tmpfile.Name())
_, err = tmpfile.Write([]byte(initialConfig))
a.NoError(err)
tmpfile.Close()
conf := config.GetConfig(tmpfile.Name())
mon := NewMonitor(conf)
defer mon.CloseAll()
time.Sleep(100 * time.Millisecond)
// Verify no apps initially
mon.monMu.Lock()
initialCount := len(mon.monitors)
mon.monMu.Unlock()
a.Equal(0, initialCount)
// Add app to config
updatedConfig := `
agent:
listen_addr: :8080
monitor_interval: 10s
bgp:
local_as: 12345
peer_as: 6789
local_ip: 192.168.1.100
origin: igp
apps:
- name: new-app
vip: 2.2.2.2/32
monitors:
- exec:echo
`
err = ioutil.WriteFile(tmpfile.Name(), []byte(updatedConfig), 0644)
a.NoError(err)
// Reload
err = mon.Reload(tmpfile.Name())
a.NoError(err)
time.Sleep(200 * time.Millisecond)
// Verify app was added
mon.monMu.Lock()
_, exists := mon.monitors["new-app"]
mon.monMu.Unlock()
a.True(exists, "New app should be added after reload")
}
func TestReloadMD5Change(t *testing.T) {
if os.Getenv("CI") != "" {
t.Skip("Skipping reload test in CI environment")
}
a := assert.New(t)
// Set environment variable for MD5 password
os.Setenv("BGP_TEST_PASSWORD", "initial_secret")
defer os.Unsetenv("BGP_TEST_PASSWORD")
initialConfig := `
agent:
listen_addr: :8080
bgp:
local_as: 12345
local_ip: 192.168.1.100
peers:
- peer_ip: 10.10.10.1
peer_as: 6789
md5_env_var: BGP_TEST_PASSWORD
origin: igp
`
tmpfile, err := ioutil.TempFile("", "gocast-test-*.yaml")
a.NoError(err)
defer os.Remove(tmpfile.Name())
_, err = tmpfile.Write([]byte(initialConfig))
a.NoError(err)
tmpfile.Close()
conf := config.GetConfig(tmpfile.Name())
mon := NewMonitor(conf)
defer mon.CloseAll()
time.Sleep(100 * time.Millisecond)
// Update environment variable
os.Setenv("BGP_TEST_PASSWORD", "updated_secret")
// Reload (MD5 env var change should trigger BGP reload)
err = mon.Reload(tmpfile.Name())
a.NoError(err)
// Note: We can't easily verify the MD5 password changed without
// actually establishing BGP sessions, but we can verify reload succeeded
a.NotNil(mon.ctrl)
}

View File

@@ -8,6 +8,7 @@ import (
) )
var execCmd = "bash" var execCmd = "bash"
var iptablesBinary = "iptables"
func getCmdList(mainCmd string) []string { func getCmdList(mainCmd string) []string {
cmdList := []string{} cmdList := []string{}
@@ -88,8 +89,8 @@ func deleteLoopback(addr *net.IPNet) error {
func natRule(op string, vip, localAddr net.IP, protocol, lport, dport string) error { func natRule(op string, vip, localAddr net.IP, protocol, lport, dport string) error {
cmd := fmt.Sprintf( cmd := fmt.Sprintf(
"iptables -t nat -%s PREROUTING -p %s -d %s --dport %s -j DNAT --to-destination %s:%s", "%s -t nat -%s PREROUTING -p %s -d %s --dport %s -j DNAT --to-destination %s:%s",
op, protocol, vip.String(), lport, localAddr.String(), dport, iptablesBinary, op, protocol, vip.String(), lport, localAddr.String(), dport,
) )
cmdList := getCmdList(cmd) cmdList := getCmdList(cmd)
_, err := exec.Command(execCmd, cmdList...).Output() _, err := exec.Command(execCmd, cmdList...).Output()
@@ -98,3 +99,10 @@ func natRule(op string, vip, localAddr net.IP, protocol, lport, dport string) er
} }
return nil return nil
} }
// SetIptablesBinary sets the iptables binary to use for NAT rules
func SetIptablesBinary(binary string) {
if binary != "" {
iptablesBinary = binary
}
}

View File

@@ -43,6 +43,71 @@ func TestAddLoopback(t *testing.T) {
assert.NotNil(t, err) assert.NotNil(t, err)
} }
func TestSetIptablesBinary(t *testing.T) {
a := assert.New(t)
// Save original value
originalBinary := iptablesBinary
defer func() {
iptablesBinary = originalBinary
}()
// Test setting custom binary
SetIptablesBinary("iptables-nft")
a.Equal("iptables-nft", iptablesBinary)
// Test setting back to default
SetIptablesBinary("iptables")
a.Equal("iptables", iptablesBinary)
// Test that empty string doesn't change the value
SetIptablesBinary("iptables-custom")
a.Equal("iptables-custom", iptablesBinary)
SetIptablesBinary("")
a.Equal("iptables-custom", iptablesBinary, "Empty string should not change the binary")
}
func TestNatRuleCommandFormat(t *testing.T) {
a := assert.New(t)
// Save original values
originalBinary := iptablesBinary
originalExecCmd := execCmd
defer func() {
iptablesBinary = originalBinary
execCmd = originalExecCmd
}()
vip := net.ParseIP("192.0.2.1")
localAddr := net.ParseIP("10.0.0.1")
// Test with default iptables
SetIptablesBinary("iptables")
err := natRule("A", vip, localAddr, "tcp", "80", "8080")
// We expect this to fail in test environment, but we can check the error message
// contains our command
if err != nil {
a.Contains(err.Error(), "iptables -t nat -A PREROUTING")
}
// Test with iptables-nft
SetIptablesBinary("iptables-nft")
err = natRule("A", vip, localAddr, "tcp", "80", "8080")
if err != nil {
a.Contains(err.Error(), "iptables-nft -t nat -A PREROUTING")
}
// Test with custom binary path
SetIptablesBinary("/usr/sbin/iptables")
err = natRule("D", vip, localAddr, "udp", "53", "5353")
if err != nil {
a.Contains(err.Error(), "/usr/sbin/iptables -t nat -D PREROUTING")
a.Contains(err.Error(), "udp")
a.Contains(err.Error(), "53")
a.Contains(err.Error(), "5353")
}
}
func TestMain(m *testing.M) { func TestMain(m *testing.M) {
switch os.Getenv("test_name") { switch os.Getenv("test_name") {
case "test_gateway": case "test_gateway":

11
main.go
View File

@@ -33,7 +33,16 @@ func main() {
go func() { go func() {
for { for {
sig := <-signalChan sig := <-signalChan
if sig == os.Interrupt || sig == syscall.SIGTERM { switch sig {
case syscall.SIGHUP:
log.Info("Received SIGHUP, reloading configuration")
if err := mon.Reload(*config); err != nil {
log.Errorf("Failed to reload configuration: %v", err)
} else {
log.Info("Configuration reloaded successfully")
}
case os.Interrupt, syscall.SIGTERM:
log.Info("Received shutdown signal, cleaning up")
mon.CloseAll() mon.CloseAll()
cancel() cancel()
return return