endpoint expiry: keep endpoints alive to smooth out reconnects

README.md

@@ -213,6 +213,9 @@ tokens-file = "path/to/client/tokens" # file that contains a list of client auth
 tokens = ["client-token-1", "client-token-n"] # set of recognized client auth tokens
 # one of tokens or tokens-file is required
 
+endpoint-expiry-disable = false # disable keeping endpoint registrations alive after client disconnect (default false)
+endpoint-expiry-timeout = "30s" # how long to keep endpoint registrations after client disconnect (default '30s')
+
 status-addr = "127.0.0.1:19180" # address to listen for incoming status connections (TCP/HTTP, [host]:port) (disabled by default)
 store-dir = "path/to/server-store" # directory for this server to persist runtime information, see Storage section for more info
 
@@ -247,6 +250,9 @@ clients-tokens-file = "path/to/client/tokens" # file containing a list of client
 clients-tokens = ["client-token-1", "client-token-n"] # list of recognized client auth tokens
 # one of client-tokens-file or client-tokens is required
 
+endpoint-expiry-disable = false # disable keeping endpoint registrations alive after client disconnect (default false)
+endpoint-expiry-timeout = "30s" # how long to keep endpoint registrations after client disconnect (default '30s')
+
 relays-tokens-file = "path/to/relay/token" # file containing a list of relay auth tokens, one token per line
 relays-tokens = ["relay-token-1", "relay-token-n"] # list of recognized relay auth tokens
 # one of relay-tokens or relay-tokens-file is required if connecting relays
@@ -587,7 +593,6 @@ by adding account management and it is one of the easiest ways to start.
 ## Planlog
 
 ### Next
- - [ ] do not discard client/peer/endpoint info immediately 
  - [ ] controlled server shutdown
  - [ ] peer identity and support for options in p2p
  - [ ] raw endpoint protocols
@@ -607,6 +612,9 @@ by adding account management and it is one of the easiest ways to start.
 
 ## Changelog
 
+### v0.15.0
+ - [x] endpoint expiry: keep endpoint registrations alive for a grace period after client disconnect to smooth out reconnects
+
 ### v0.14.0
  - [x] rewrite relay to not depend on control connection
  - [x] complete migration to relay v2

cmd/connet/control.go

@@ -19,6 +19,9 @@ type ControlConfig struct {
 	ClientsTokens            []string           `toml:"clients-tokens"`
 	ClientsTokenRestrictions []TokenRestriction `toml:"clients-token-restriction"`
 
+	EndpointExpiryDisable bool          `toml:"endpoint-expiry-disable"`
+	EndpointExpiryTimeout durationValue `toml:"endpoint-expiry-timeout"`
+
 	RelaysIngresses         []ControlIngress `toml:"relays-ingress"`
 	RelaysTokensFile        string           `toml:"relays-tokens-file"`
 	RelaysTokens            []string         `toml:"relays-tokens"`
@@ -72,6 +75,9 @@ func controlCmd() *cobra.Command {
 	cmd.Flags().StringArrayVar(&clientIngress.AllowCIDRs, "clients-allow-cidr", nil, "list of allowed networks for client connections (CIDR format)")
 	cmd.Flags().StringArrayVar(&clientIngress.DenyCIDRs, "clients-deny-cidr", nil, "list of denied networks for client connections (CIDR format)")
 
+	cmd.Flags().BoolVar(&flagsConfig.Control.EndpointExpiryDisable, "endpoint-expiry-disable", false, "disable keeping endpoint registrations alive after client disconnect (default false)")
+	cmd.Flags().Var(&flagsConfig.Control.EndpointExpiryTimeout, "endpoint-expiry-timeout", "how long to keep endpoint registrations after client disconnect (default '30s')")
+
 	cmd.Flags().StringVar(&flagsConfig.Control.RelaysTokensFile, "relays-tokens-file", "", "file containing a list of relay auth tokens (token per line)")
 	cmd.Flags().StringArrayVar(&flagsConfig.Control.RelaysTokens, "relays-tokens", nil, "list of relay auth tokens (fallback when 'relay-tokens-file' is not specified)")
 
@@ -146,6 +152,8 @@ func controlRun(ctx context.Context, cfg ControlConfig, logger *slog.Logger) err
 		return err
 	}
 
+	controlCfg.ClientsEndpointExpiry = resolveEndpointExpiry(cfg.EndpointExpiryDisable, cfg.EndpointExpiryTimeout)
+
 	var usedRelaysDefault bool
 	for ix, ingressCfg := range cfg.RelaysIngresses {
 		if ingressCfg.Addr == "" && !usedRelaysDefault {
@@ -268,6 +276,9 @@ func (c *ControlConfig) merge(o ControlConfig) {
 	}
 	c.ClientsTokenRestrictions = mergeSlices(c.ClientsTokenRestrictions, o.ClientsTokenRestrictions)
 
+	c.EndpointExpiryDisable = c.EndpointExpiryDisable || o.EndpointExpiryDisable
+	c.EndpointExpiryTimeout = override(c.EndpointExpiryTimeout, o.EndpointExpiryTimeout)
+
 	c.RelaysIngresses = mergeSlices(c.RelaysIngresses, o.RelaysIngresses)
 	if len(o.RelaysTokens) > 0 || o.RelaysTokensFile != "" { // new config completely overrides tokens
 		c.RelaysTokens = o.RelaysTokens

cmd/connet/main.go

@@ -307,3 +307,13 @@ func (d *durationValue) String() string { return (*time.Duration)(d).String() }
 func (d *durationValue) get() time.Duration {
 	return time.Duration(*d)
 }
+
+func resolveEndpointExpiry(disabled bool, timeout durationValue) time.Duration {
+	if disabled {
+		return 0
+	}
+	if d := timeout.get(); d > 0 {
+		return d
+	}
+	return 30 * time.Second
+}

cmd/connet/server.go

@@ -17,6 +17,9 @@ type ServerConfig struct {
 	Tokens            []string           `toml:"tokens"`
 	TokenRestrictions []TokenRestriction `toml:"token-restriction"`
 
+	EndpointExpiryDisable bool          `toml:"endpoint-expiry-disable"`
+	EndpointExpiryTimeout durationValue `toml:"endpoint-expiry-timeout"`
+
 	RelayIngresses []RelayIngress `toml:"relay-ingress"`
 
 	StatusAddr string `toml:"status-addr"`
@@ -45,6 +48,9 @@ func serverCmd() *cobra.Command {
 	cmd.Flags().StringArrayVar(&clientIngress.AllowCIDRs, "allow-cidr", nil, "list of allowed networks for client connections (CIDR format)")
 	cmd.Flags().StringArrayVar(&clientIngress.DenyCIDRs, "deny-cidr", nil, "list of denied networks for client connections (CIDR format)")
 
+	cmd.Flags().BoolVar(&flagsConfig.Server.EndpointExpiryDisable, "endpoint-expiry-disable", false, "disable keeping endpoint registrations alive after client disconnect (default false)")
+	cmd.Flags().Var(&flagsConfig.Server.EndpointExpiryTimeout, "endpoint-expiry-timeout", "how long to keep endpoint registrations after client disconnect (default '30s')")
+
 	var relayIngress RelayIngress
 	cmd.Flags().StringVar(&relayIngress.Addr, "relay-addr", "", "relay clients server address (UDP/QUIC, [host]:port) (defaults to ':19191')")
 	cmd.Flags().StringArrayVar(&relayIngress.Hostports, "relay-hostport", nil, `list of host[:port]s advertised by the control server for clients to connect to this relay
@@ -64,9 +70,11 @@ func serverCmd() *cobra.Command {
 		if !clientIngress.isZero() {
 			flagsConfig.Server.Ingresses = append(flagsConfig.Server.Ingresses, clientIngress)
 		}
+
 		if !relayIngress.isZero() {
 			flagsConfig.Server.RelayIngresses = append(flagsConfig.Server.RelayIngresses, relayIngress)
 		}
+
 		cfg.merge(flagsConfig)
 
 		logger, err := logger(cfg)
@@ -116,6 +124,9 @@ func serverRun(ctx context.Context, cfg ServerConfig, logger *slog.Logger) error
 	}
 	opts = append(opts, server.ClientsAuthenticator(clientAuth))
 
+	endpointExpiry := resolveEndpointExpiry(cfg.EndpointExpiryDisable, cfg.EndpointExpiryTimeout)
+	opts = append(opts, server.ClientsEndpointExpiry(endpointExpiry))
+
 	var usedRelayDefault bool
 	for ix, ingressCfg := range cfg.RelayIngresses {
 		if ingressCfg.Addr == "" && !usedRelayDefault {
@@ -159,6 +170,9 @@ func (c *ServerConfig) merge(o ServerConfig) {
 	}
 	c.TokenRestrictions = mergeSlices(c.TokenRestrictions, o.TokenRestrictions)
 
+	c.EndpointExpiryDisable = c.EndpointExpiryDisable || o.EndpointExpiryDisable
+	c.EndpointExpiryTimeout = override(c.EndpointExpiryTimeout, o.EndpointExpiryTimeout)
+
 	c.RelayIngresses = mergeSlices(c.RelayIngresses, o.RelayIngresses)
 
 	c.StatusAddr = override(c.StatusAddr, o.StatusAddr)

server/config.go

@@ -5,6 +5,7 @@ import (
 	"log/slog"
 	"net"
 	"os"
+	"time"
 
 	"github.com/connet-dev/connet/model"
 	"github.com/connet-dev/connet/server/control"
@@ -13,8 +14,9 @@ import (
 )
 
 type serverConfig struct {
-	clientsIngresses []control.Ingress
-	clientsAuth      control.ClientAuthenticator
+	clientsIngresses      []control.Ingress
+	clientsAuth           control.ClientAuthenticator
+	clientsEndpointExpiry time.Duration
 
 	relayIngresses []relay.Ingress
 
@@ -24,7 +26,8 @@ type serverConfig struct {
 
 func newServerConfig(opts []Option) (*serverConfig, error) {
 	cfg := &serverConfig{
-		logger: slog.Default(),
+		clientsEndpointExpiry: 30 * time.Second,
+		logger:                slog.Default(),
 	}
 	for _, opt := range opts {
 		if err := opt(cfg); err != nil {
@@ -100,6 +103,13 @@ func ClientsAuthenticator(clientsAuth control.ClientAuthenticator) Option {
 	}
 }
 
+func ClientsEndpointExpiry(d time.Duration) Option {
+	return func(cfg *serverConfig) error {
+		cfg.clientsEndpointExpiry = d
+		return nil
+	}
+}
+
 func RelayIngress(icfg relay.Ingress) Option {
 	return func(cfg *serverConfig) error {
 		cfg.relayIngresses = append(cfg.relayIngresses, icfg)