all: make discovery refresh interval configurable

config.go

@@ -179,23 +179,24 @@ func (c *Config) FirstUpstream() *UpstreamConfig {
 
 // ServiceConfig specifies the general ctrld config.
 type ServiceConfig struct {
-	LogLevel              string `mapstructure:"log_level" toml:"log_level,omitempty"`
-	LogPath               string `mapstructure:"log_path" toml:"log_path,omitempty"`
-	CacheEnable           bool   `mapstructure:"cache_enable" toml:"cache_enable,omitempty"`
-	CacheSize             int    `mapstructure:"cache_size" toml:"cache_size,omitempty"`
-	CacheTTLOverride      int    `mapstructure:"cache_ttl_override" toml:"cache_ttl_override,omitempty"`
-	CacheServeStale       bool   `mapstructure:"cache_serve_stale" toml:"cache_serve_stale,omitempty"`
-	MaxConcurrentRequests *int   `mapstructure:"max_concurrent_requests" toml:"max_concurrent_requests,omitempty" validate:"omitempty,gte=0"`
-	DHCPLeaseFile         string `mapstructure:"dhcp_lease_file_path" toml:"dhcp_lease_file_path" validate:"omitempty,file"`
-	DHCPLeaseFileFormat   string `mapstructure:"dhcp_lease_file_format" toml:"dhcp_lease_file_format" validate:"required_unless=DHCPLeaseFile '',omitempty,oneof=dnsmasq isc-dhcp"`
-	DiscoverMDNS          *bool  `mapstructure:"discover_mdns" toml:"discover_mdns,omitempty"`
-	DiscoverARP           *bool  `mapstructure:"discover_arp" toml:"discover_arp,omitempty"`
-	DiscoverDHCP          *bool  `mapstructure:"discover_dhcp" toml:"discover_dhcp,omitempty"`
-	DiscoverPtr           *bool  `mapstructure:"discover_ptr" toml:"discover_ptr,omitempty"`
-	DiscoverHosts         *bool  `mapstructure:"discover_hosts" toml:"discover_hosts,omitempty"`
-	ClientIDPref          string `mapstructure:"client_id_preference" toml:"client_id_preference,omitempty" validate:"omitempty,oneof=host mac"`
-	Daemon                bool   `mapstructure:"-" toml:"-"`
-	AllocateIP            bool   `mapstructure:"-" toml:"-"`
+	LogLevel                string `mapstructure:"log_level" toml:"log_level,omitempty"`
+	LogPath                 string `mapstructure:"log_path" toml:"log_path,omitempty"`
+	CacheEnable             bool   `mapstructure:"cache_enable" toml:"cache_enable,omitempty"`
+	CacheSize               int    `mapstructure:"cache_size" toml:"cache_size,omitempty"`
+	CacheTTLOverride        int    `mapstructure:"cache_ttl_override" toml:"cache_ttl_override,omitempty"`
+	CacheServeStale         bool   `mapstructure:"cache_serve_stale" toml:"cache_serve_stale,omitempty"`
+	MaxConcurrentRequests   *int   `mapstructure:"max_concurrent_requests" toml:"max_concurrent_requests,omitempty" validate:"omitempty,gte=0"`
+	DHCPLeaseFile           string `mapstructure:"dhcp_lease_file_path" toml:"dhcp_lease_file_path" validate:"omitempty,file"`
+	DHCPLeaseFileFormat     string `mapstructure:"dhcp_lease_file_format" toml:"dhcp_lease_file_format" validate:"required_unless=DHCPLeaseFile '',omitempty,oneof=dnsmasq isc-dhcp"`
+	DiscoverMDNS            *bool  `mapstructure:"discover_mdns" toml:"discover_mdns,omitempty"`
+	DiscoverARP             *bool  `mapstructure:"discover_arp" toml:"discover_arp,omitempty"`
+	DiscoverDHCP            *bool  `mapstructure:"discover_dhcp" toml:"discover_dhcp,omitempty"`
+	DiscoverPtr             *bool  `mapstructure:"discover_ptr" toml:"discover_ptr,omitempty"`
+	DiscoverHosts           *bool  `mapstructure:"discover_hosts" toml:"discover_hosts,omitempty"`
+	DiscoverRefreshInterval int    `mapstructure:"discover_refresh_interval" toml:"discover_refresh_interval,omitempty"`
+	ClientIDPref            string `mapstructure:"client_id_preference" toml:"client_id_preference,omitempty" validate:"omitempty,oneof=host mac"`
+	Daemon                  bool   `mapstructure:"-" toml:"-"`
+	AllocateIP              bool   `mapstructure:"-" toml:"-"`
 }
 
 // NetworkConfig specifies configuration for networks where ctrld will handle requests.

docs/config.md

@@ -200,6 +200,14 @@ Perform LAN client discovery using hosts file.
 - Required: no
 - Default: true
 
+### discover_refresh_interval
+Time in seconds between each discovery refresh loop to update new client information data. 
+The default value is 120 seconds, lower this value to make the discovery process run more aggressively.
+
+- Type: integer
+- Required: no
+- Default: 120
+
 ### dhcp_lease_file_path
 Relative or absolute path to a custom DHCP leases file location. 
 

internal/clientinfo/client_info.go

@@ -70,6 +70,7 @@ type Table struct {
 	hostnameResolvers []HostnameResolver
 	refreshers        []refresher
 	initOnce          sync.Once
+	refreshInterval   int
 
 	dhcp           *dhcp
 	merlin         *merlinDiscover
@@ -88,12 +89,17 @@ type Table struct {
 }
 
 func NewTable(cfg *ctrld.Config, selfIP, cdUID string, ns []string) *Table {
+	refreshInterval := cfg.Service.DiscoverRefreshInterval
+	if refreshInterval <= 0 {
+		refreshInterval = 2 * 60 // 2 minutes
+	}
 	return &Table{
-		svcCfg:         cfg.Service,
-		quitCh:         make(chan struct{}),
-		selfIP:         selfIP,
-		cdUID:          cdUID,
-		ptrNameservers: ns,
+		svcCfg:          cfg.Service,
+		quitCh:          make(chan struct{}),
+		selfIP:          selfIP,
+		cdUID:           cdUID,
+		ptrNameservers:  ns,
+		refreshInterval: refreshInterval,
 	}
 }
 
@@ -104,8 +110,9 @@ func (t *Table) AddLeaseFile(name string, format ctrld.LeaseFileFormat) {
 	clientInfoFiles[name] = format
 }
 
+// RefreshLoop runs all the refresher to update new client info data.
 func (t *Table) RefreshLoop(ctx context.Context) {
-	timer := time.NewTicker(time.Minute * 5)
+	timer := time.NewTicker(time.Second * time.Duration(t.refreshInterval))
 	defer timer.Stop()
 	for {
 		select {