added the keepalive support from the client side

client.go

@@ -29,6 +29,7 @@ import "google.golang.org/grpc"
 import "google.golang.org/grpc/codes"
 import "google.golang.org/grpc/credentials"
 import "google.golang.org/grpc/credentials/insecure"
+import "google.golang.org/grpc/keepalive"
 import "google.golang.org/grpc/peer"
 import "google.golang.org/grpc/status"
 
@@ -58,11 +59,13 @@ type ClientRouteConfig struct {
 }
 
 type ClientConnConfig struct {
-	ServerAddrs []string
-	Routes      []ClientRouteConfig
+	ServerAddrs     []string
+	Routes          []ClientRouteConfig
+	ServerPingIntvl time.Duration
+	ServerPingTmout time.Duration
 	ServerSeedTmout time.Duration
 	ServerAuthority string // http2 :authority header
-	ClientToken string
+	ClientToken     string
 	CloseOnConnErrorEvent bool
 }
 
@@ -89,6 +92,11 @@ type ClientConfig struct {
 
 	Token string // to send to the server for identification
 
+	// default values
+	RpcPingIntvl time.Duration
+	RpcPingTmout time.Duration
+	RpcSeedTmout time.Duration
+
 	// default target for rpx
 	RpxTargetAddr string
 	RpxTargetTls *tls.Config
@@ -174,6 +182,9 @@ type Client struct {
 
 	pty_user string
 	pty_shell string
+	rpc_ping_intvl time.Duration
+	rpc_ping_tmout time.Duration
+	rpc_seed_tmout time.Duration
 	xterm_html string
 }
 
@@ -1310,6 +1321,9 @@ func (cts *ClientConn) RunTask(wg *sync.WaitGroup) {
 	var p *peer.Peer
 	var ok bool
 	var err error
+	var ping_intvl time.Duration
+	var ping_tmout time.Duration
+	var seed_tmout time.Duration
 	var opts []grpc.DialOption
 
 	defer wg.Done() // arrange to call at the end of this function
@@ -1319,9 +1333,29 @@ func (cts *ClientConn) RunTask(wg *sync.WaitGroup) {
 start_over:
 	cts.State.Store(CLIENT_CONN_CONNECTING)
 	cts.cfg.Index = (cts.cfg.Index + 1) % len(cts.cfg.ServerAddrs)
-	cts.C.log.Write(cts.Sid, LOG_INFO, "Connecting to server[%d] %s", cts.cfg.Index, cts.cfg.ServerAddrs[cts.cfg.Index])
 
-	opts = []grpc.DialOption{ }
+	ping_intvl = cts.cfg.ServerPingIntvl
+	if ping_intvl <= 0 {
+		ping_intvl = cts.C.rpc_ping_intvl
+		// the server's minimum policy defaults to 5 minutes.
+		// the client's default interval is 10s. i want it to be 10m instead.
+		if ping_intvl <= 0 { ping_intvl = 10 * time.Minute }
+	}
+	ping_tmout = cts.cfg.ServerPingTmout
+	if ping_tmout <= 0 { ping_tmout = cts.C.rpc_ping_tmout }
+	seed_tmout = cts.cfg.ServerSeedTmout
+	if seed_tmout <= 0 { seed_tmout = cts.C.rpc_seed_tmout }
+
+	cts.C.log.Write(cts.Sid, LOG_INFO, "Connecting to server[%d] %s ping_intvl[%v] ping_tmout[%v] seed_tmout[%v]", cts.cfg.Index, cts.cfg.ServerAddrs[cts.cfg.Index], ping_intvl, ping_tmout, seed_tmout)
+
+	opts = []grpc.DialOption{}
+
+	opts = append(opts, grpc.WithKeepaliveParams(keepalive.ClientParameters{
+		Time: ping_intvl,
+		Timeout: ping_tmout,
+		PermitWithoutStream: true,
+	}))
+
 	if cts.C.rpc_tls == nil {
 		opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()))
 		if cts.cfg.ServerAuthority != "" { opts = append(opts, grpc.WithAuthority(cts.cfg.ServerAuthority)) }
@@ -1334,8 +1368,8 @@ start_over:
 			opts = append(opts, grpc.WithAuthority(cts.C.rpc_tls.ServerName))
 		}
 	}
-	if cts.cfg.ServerSeedTmout > 0 {
-		opts = append(opts, grpc.WithUnaryInterceptor(timed_interceptor(cts.cfg.ServerSeedTmout)))
+	if seed_tmout > 0 {
+		opts = append(opts, grpc.WithUnaryInterceptor(timed_interceptor(seed_tmout)))
 	}
 
 	cts.conn, err = grpc.NewClient(cts.cfg.ServerAddrs[cts.cfg.Index], opts...)
@@ -2270,6 +2304,10 @@ func NewClient(ctx context.Context, name string, logger Logger, cfg *ClientConfi
 	c.stop_chan = make(chan bool, 8)
 	c.bulletin = NewBulletin[*ClientEvent](&c, 1024)
 
+	c.rpc_ping_intvl = cfg.RpcPingIntvl
+	c.rpc_ping_tmout = cfg.RpcPingTmout
+	c.rpc_seed_tmout = cfg.RpcSeedTmout
+
 	c.rpc_tls = cfg.RpcTls
 	c.rpx_target_addr = cfg.RpxTargetAddr
 	c.rpx_target_addr_org = cfg.RpxTargetAddr

cmd/config.go

@@ -92,9 +92,11 @@ type RPCServiceConfig struct { // rpc server-side configuration
 }
 
 type RPCEndpointConfig struct { // rpc client-side configuration
-	Authority   string        `yaml:"authority"`
-	Addrs       []string      `yaml:"addresses"`
-	SeedTmout   time.Duration `yaml:"seed-timeout"`
+	Authority    string        `yaml:"authority"`
+	Addrs        []string      `yaml:"addresses"`
+	PingIntvl    time.Duration `yaml:"ping-interval"`
+	PingTmout    time.Duration `yaml:"ping-timeout"`
+	SeedTmout    time.Duration `yaml:"seed-timeout"`
 }
 
 type ServerAppConfig  struct {
@@ -122,6 +124,9 @@ type ClientAppConfig  struct {
 	TokenFile     string        `yaml:"token-file"`
 	PtyUser       string        `yaml:"pty-user"`
 	PtyShell      string        `yaml:"pty-shell"`
+	RpcPingIntvl  time.Duration `yaml:"rpc-ping-interval"`
+	RpcPingTmout  time.Duration `yaml:"rpc-ping-timeout"`
+	RpcSeedTmout  time.Duration `yaml:"rpc-seed-timeout"`
 	XtermHtmlFile string        `yaml:"xterm-html-file"`
 }
 

cmd/main.go

@@ -297,6 +297,8 @@ func client_main(ctl_addrs []string, rpc_addrs []string, route_configs []string,
 	config.CtlAuth, err = make_http_auth_config(&cfg.CTL.Service.Auth)
 	if err != nil { return err }
 
+	cc.ServerPingIntvl = cfg.RPC.Endpoint.PingIntvl
+	cc.ServerPingTmout = cfg.RPC.Endpoint.PingTmout
 	cc.ServerSeedTmout = cfg.RPC.Endpoint.SeedTmout
 	cc.ServerAuthority = cfg.RPC.Endpoint.Authority
 	pty_user = cfg.APP.PtyUser
@@ -306,6 +308,10 @@ func client_main(ctl_addrs []string, rpc_addrs []string, route_configs []string,
 	config.PeerConnMax = cfg.APP.MaxPeers
 	config.PeerConnTmout = cfg.APP.PeerConnTmout
 
+	config.RpcPingIntvl = cfg.APP.RpcPingIntvl // app-level default
+	config.RpcPingTmout = cfg.APP.RpcPingTmout // app-level default
+	config.RpcSeedTmout = cfg.APP.RpcSeedTmout // app-level default
+
 	if cfg.APP.TokenText != "" {
 		config.Token = cfg.APP.TokenText
 	} else if cfg.APP.TokenFile != "" {