func (cl *gatewayClient) monitorUplink() {
var retries int
newStream:
for {
ctx, cancel := context.WithCancel(cl.Context())
cl.uplink.Lock()
cl.uplink.cancel = cancel
cl.uplink.Unlock()
stream, err := cl.client.client.GatewayUplink(ctx)
if err != nil {
cl.Ctx.WithError(errors.FromGRPCError(err)).Warn("Failed to open new monitor uplink stream")
retries++
time.Sleep(backoff.Backoff(retries))
continue
}
retries = 0
cl.Ctx.Debug("Opened new monitor uplink stream")
// The actual stream
go func() {
for {
select {
case <-ctx.Done():
return
case uplink, ok := <-cl.uplink.ch:
if ok {
stream.Send(uplink)
cl.Ctx.Debug("Sent uplink to monitor")
}
}
}
}()
msg := new(empty.Empty)
for {
if err := stream.RecvMsg(&msg); err != nil {
cl.Ctx.WithError(errors.FromGRPCError(err)).Warn("Received error on monitor uplink stream, closing...")
stream.CloseSend()
cl.Ctx.Debug("Closed monitor uplink stream")
cl.uplink.Lock()
cl.uplink.cancel()
cl.uplink.cancel = nil
cl.uplink.Unlock()
retries++
time.Sleep(backoff.Backoff(retries))
continue newStream
}
}
}
}
// WithTTNDialer creates a dialer for TTN
func WithTTNDialer() grpc.DialOption {
return grpc.WithDialer(func(addr string, timeout time.Duration) (net.Conn, error) {
ctx := log.Get().WithField("Address", addr)
d := net.Dialer{Timeout: timeout, KeepAlive: KeepAlive}
var retries int
for {
conn, err := d.Dial("tcp", addr)
if err == nil {
ctx.Debug("Connected to gRPC server")
return conn, nil
}
if err, ok := err.(*net.OpError); ok && err.Op == "dial" && retries <= MaxRetries {
ctx.WithError(err).Debug("Could not connect to gRPC server, reconnecting...")
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
return nil, err
}
})
}
// NewMonitoredRouterStream starts and monitors a RouterStream
func NewMonitoredRouterStream(client BrokerClient, getContextFunc func() context.Context) RouterStream {
s := &routerStream{
up: make(chan *UplinkMessage, DefaultBufferSize),
down: make(chan *DownlinkMessage, DefaultBufferSize),
err: make(chan error),
}
s.setup.Add(1)
s.client = client
s.ctx = log.Get()
go func() {
var retries int
for {
// Session channels
up := make(chan *UplinkMessage)
errCh := make(chan error)
// Session client
var ctx context.Context
ctx, s.cancel = context.WithCancel(getContextFunc())
client, err := s.client.Associate(ctx)
s.setup.Done()
if err != nil {
s.ctx.WithError(err).Warn("Could not start Associate stream, retrying...")
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
retries = 0
s.ctx.Debug("Started Associate stream")
// Receive downlink errors
go func() {
for {
message, err := client.Recv()
if message != nil {
s.ctx.Debug("Receiving Downlink message")
select {
case s.down <- message:
default:
s.ctx.Warn("Dropping Downlink message, buffer full")
}
}
if err != nil {
errCh <- err
break
}
}
close(errCh)
}()
// Send uplink
go func() {
for message := range up {
s.ctx.Debug("Sending Uplink message")
if err := client.Send(message); err != nil {
s.ctx.WithError(err).Warn("Error sending Uplink message")
break
}
}
}()
// Monitoring
var mErr error
monitor:
for {
select {
case mErr = <-errCh:
break monitor
case msg, ok := <-s.up:
if !ok {
break monitor // channel closed
}
up <- msg
}
}
close(up)
client.CloseSend()
if mErr == nil || mErr == io.EOF || grpc.Code(mErr) == codes.Canceled {
s.ctx.Debug("Stopped Associate stream")
} else {
s.ctx.WithError(mErr).Warn("Error in Associate stream")
}
if s.closing {
break
}
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
}
}()
return s
}
// NewMonitoredHandlerSubscribeStream starts and monitors a HandlerSubscribeStream
func NewMonitoredHandlerSubscribeStream(client BrokerClient, getContextFunc func() context.Context) HandlerSubscribeStream {
s := &handlerSubscribeStream{
ch: make(chan *DeduplicatedUplinkMessage, DefaultBufferSize),
err: make(chan error),
}
s.setup.Add(1)
s.client = client
s.ctx = log.Get()
go func() {
var client Broker_SubscribeClient
var err error
var retries int
var message *DeduplicatedUplinkMessage
for {
// Session client
var ctx context.Context
ctx, s.cancel = context.WithCancel(getContextFunc())
client, err = s.client.Subscribe(ctx, &SubscribeRequest{})
s.setup.Done()
if err != nil {
if grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped Uplink stream")
break
}
s.ctx.WithError(err).Warn("Could not start Uplink stream, retrying...")
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
retries = 0
s.ctx.Info("Started Uplink stream")
for {
message, err = client.Recv()
if message != nil {
s.ctx.Debug("Receiving Uplink message")
select {
case s.ch <- message:
default:
s.ctx.Warn("Dropping Uplink message, buffer full")
}
}
if err != nil {
break
}
}
if err == nil || err == io.EOF || grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped Uplink stream")
} else {
s.ctx.WithError(err).Warn("Error in Uplink stream")
}
if s.closing {
break
}
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
}
close(s.ch)
}()
return s
}
// NewMonitoredHandlerPublishStream starts and monitors a HandlerPublishStream
func NewMonitoredHandlerPublishStream(client BrokerClient, getContextFunc func() context.Context) HandlerPublishStream {
s := &handlerPublishStream{
ch: make(chan *DownlinkMessage, DefaultBufferSize),
err: make(chan error),
}
s.setup.Add(1)
s.client = client
s.ctx = log.Get()
go func() {
var retries int
for {
// Session channels
ch := make(chan *DownlinkMessage)
errCh := make(chan error)
// Session client
client, err := s.client.Publish(getContextFunc())
s.setup.Done()
if err != nil {
if grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped Downlink stream")
break
}
s.ctx.WithError(err).Warn("Could not start Downlink stream, retrying...")
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
retries = 0
s.ctx.Info("Started Downlink stream")
// Receive errors
go func() {
empty := new(empty.Empty)
if err := client.RecvMsg(empty); err != nil {
errCh <- err
}
close(errCh)
}()
// Send
go func() {
for message := range ch {
s.ctx.Debug("Sending Downlink message")
if err := client.Send(message); err != nil {
s.ctx.WithError(err).Warn("Error sending Downlink message")
break
}
}
}()
// Monitoring
var mErr error
monitor:
for {
select {
case mErr = <-errCh:
break monitor
case msg, ok := <-s.ch:
if !ok {
break monitor // channel closed
}
ch <- msg
}
}
close(ch)
client.CloseAndRecv()
if mErr == nil || mErr == io.EOF || grpc.Code(mErr) == codes.Canceled {
s.ctx.Debug("Stopped Downlink stream")
} else {
s.ctx.WithError(mErr).Warn("Error in Downlink stream")
}
if s.closing {
break
}
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
}
}()
return s
}
// NewMonitoredGatewayStatusStream starts and monitors a GatewayStatusStream
func NewMonitoredGatewayStatusStream(client RouterClientForGateway) GatewayStatusStream {
s := &gatewayStatusStream{
ch: make(chan *gateway.Status, DefaultBufferSize),
err: make(chan error),
}
s.setup.Add(1)
s.client = client
s.ctx = client.GetLogger()
go func() {
var retries int
for {
// Session channels
ch := make(chan *gateway.Status)
errCh := make(chan error)
// Session client
client, err := s.client.GatewayStatus()
s.setup.Done()
if err != nil {
if grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped GatewayStatus stream")
break
}
s.ctx.WithError(err).Warn("Could not start GatewayStatus stream, retrying...")
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
s.ctx.Info("Started GatewayStatus stream")
// Receive errors
go func() {
empty := new(empty.Empty)
if err := client.RecvMsg(empty); err != nil {
errCh <- err
}
close(errCh)
}()
// Send
go func() {
for status := range ch {
s.ctx.Debug("Sending GatewayStatus message")
if err := client.Send(status); err != nil {
s.ctx.WithError(err).Warn("Error sending GatewayStatus message")
break
}
}
}()
// Monitoring
var mErr error
monitor:
for {
select {
case <-time.After(10 * time.Second):
retries = 0
case mErr = <-errCh:
break monitor
case msg, ok := <-s.ch:
if !ok {
break monitor // channel closed
}
ch <- msg
}
}
close(ch)
client.CloseAndRecv()
if mErr == nil || mErr == io.EOF || grpc.Code(mErr) == codes.Canceled {
s.ctx.Debug("Stopped GatewayStatus stream")
} else {
s.ctx.WithError(mErr).Warn("Error in GatewayStatus stream")
}
if s.closing {
break
}
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
}
}()
return s
}
// NewMonitoredDownlinkStream starts and monitors a DownlinkStream
func NewMonitoredDownlinkStream(client RouterClientForGateway) DownlinkStream {
s := &downlinkStream{
ch: make(chan *DownlinkMessage, DefaultBufferSize),
err: make(chan error),
}
s.setup.Add(1)
s.client = client
s.ctx = client.GetLogger()
go func() {
var client Router_SubscribeClient
var err error
var retries int
var message *DownlinkMessage
for {
client, s.cancel, err = s.client.Subscribe()
s.setup.Done()
if err != nil {
if grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped Downlink stream")
break
}
s.ctx.WithError(err).Warn("Could not start Downlink stream, retrying...")
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
continue
}
s.ctx.Info("Started Downlink stream")
for {
message, err = client.Recv()
if message != nil {
s.ctx.Debug("Receiving Downlink message")
select {
case s.ch <- message:
default:
s.ctx.Warn("Dropping Downlink message, buffer full")
}
}
if err != nil {
break
}
retries = 0
}
if err == nil || err == io.EOF || grpc.Code(err) == codes.Canceled {
s.ctx.Debug("Stopped Downlink stream")
} else {
s.ctx.WithError(err).Warn("Error in Downlink stream")
}
if s.closing {
break
}
s.setup.Add(1)
time.Sleep(backoff.Backoff(retries))
retries++
}
close(s.ch)
}()
return s
}
