i try to trigger the websocket to push notification to client , but jhipster microservices doesn't support websocket in non-gateway service,
so i try to send the websocket message in a Gateway controller, and call this controller in other services with feignclient, but it seems doesn't work to call gateway controller in other service.
#PostMapping("/notify")
#Timed
public ResponseEntity<String> sendNotification(#RequestBody TodoDTO todoDTO) {
String dest = "/topic/notify/";
if (StringUtils.isNotEmpty(todoDTO.getTo())) {
dest += todoDTO.getTo();
} else if (StringUtils.isNotEmpty(todoDTO.getToShopId())) {
dest += todoDTO.getToShopId();
} else if (StringUtils.isNotEmpty(todoDTO.getToParentShopId())) {
dest += todoDTO.getToParentShopId();
}
messagingTemplate.convertAndSend(dest, todoDTO);
return ResponseEntity.ok("SUCCESS");
}
does anyone know the best practice when using websocket in jhipster microservices ?
Related
I am trying to write a program to pull messages from a message broker via Vert.x AMQP client. I want to make the program try to reconnect on broker down. Currently if I turn off the broker container, the program doesn't react. Below is my code.. What do I miss ?
public class BrokerConnector {
public void consumeEventsQueue() {
AmqpClientOptions options = new AmqpClientOptions()
.setHost("localhost")
.setPort(5672)
.setUsername("")
.setPassword("");
AmqpClient amqpClient = AmqpClient.create(options);
amqpClient.connect(con -> {
if (con.failed()) {
System.out.println("Unable to connect to the broker");
} else {
System.out.println("Connection succeeded");
}
});
amqpClient.createReceiver("MY_QUEUE",
done -> {
if (done.failed()) {
System.out.println("Unable to create receiver");
} else {
AmqpReceiver receiver = done.result();
receiver.handler(msg -> {
System.out.println("Received " + msg.bodyAsString());
});
}
}
);
}
}
To my knowledge (and from peeking at the source) the vertx AMQP client doesn't have automatic client reconnect so it seems quite normal that on loss of connection you application is failing. The client exposes an exception handler that you can hook and recreate your client resources from when the connection drops. There are some clients for AMQP that do have automatic reconnect built in like Qpid JMS or the Qpid protonj2 client.
I am using STOMP over websockets with spring boot. Is there a possibility to send a message to a specific subscription? I subscribe to the STOMP endpoints using a STOMP header containing an id field according to the stomp documentation I want this id to be used to determine the clients who should receive a message, but spring seems not to use this id. I can not just use sendToUser because two clients can have the same user id e.g. if a user has two opened browser windows. Only one specific window should receive the message.
In the following example I have two connected clients which are using the same user, but different ids in the STOMP header.
Client1-ID: a32d66bf-03c7-47a4-aea0-e464c0727842
Client2-ID: b3673d33-1bf2-461e-8df3-35b7af07371b
In spring I have executed the following Kotlin code:
val subscriptions = userRegistry.findSubscriptions {
it.destination == "/user/topic/operations/$operationId/runs"
}
subscriptions.forEach{
println("subscription id: ${it.id}");
println("session id: ${it.session.id}");
println("user id ${it.session.user.name}");
}
The output:
subscription id: sub-7
session id: mcjpgn2i
user id 4a27ef88-25eb-4175-a872-f46e7b9d0564
subscription id: sub-7
session id: 0dxuvjgp
user id 4a27ef88-25eb-4175-a872-f46e7b9d0564
There is no sign of the id I have passed to the stomp header.
Is it possible to send a message to one specific subscription determined by the id I have passed with the header?
I got it working.
First of all, there was something wrong with my client setup. I have set the subscription id in the connection header like this:
this.stompClient.webSocketFactory = (): WebSocket => new SockJS("/ws");
this.stompClient.connectHeaders = { id: subscriptionId };
this.stompClient.activate();
But the subscription header has to be set in the subscription header:
this.stompClient.subscribe(this.commonEndpoint,
this.onMessageReceived.bind(this),
{ id: subScriptionId });
If I do this, spring is correctly using this id as the subscription id, instead of using some default like sub-7.
According to that thread I can send messages to specific sessions instead of user.
With the following code I can send a message to a specific subscription:
val subscriptions = userRegistry.findSubscriptions {
it.destination == "/user/topic/operations/$operationId/runs"
}
subscriptions.forEach {
if(it.id === mySubscriptionId){
val headerAccessor =
SimpMessageHeaderAccessor.create(SimpMessageType.MESSAGE)
headerAccessor.sessionId = it.session.id
headerAccessor.setLeaveMutable(true)
simpMessagingTemplate.convertAndSendToUser(it.session.id,
"/topic/operations/runs", messageResponseEntity,
headerAccessor.getMessageHeaders())
}
}
I'm able to send message to a specific subscription using SimpMessagingTemplate.
#Autowired
private final SimpMessagingTemplate messagingTemplate;
public void sendMessage(String simpUserId, String destination, String message) {
try {
messagingTemplate.convertAndSendToUser(simpUserId, destination, message);
} catch (Exception ex) {
LOG.error("Exception occurred while sending message [message={}]", ex.getMessage(), ex);
}
}
You may refer SimpMessagingTemplate.convertAndSendToUser
The EndpointName property in a ConsumerDefinition file seems to be ignored by MassTransit. I know the ConsumerDefinition is being used because the retry logic works. How do I get different commands to go to a different queue? It seems that I can get them all to go through one central queue but I don't think this is best practice for commands.
Here is my app configuration that executes on startup when creating the MassTransit bus.
Bus.Factory.CreateUsingAzureServiceBus(cfg =>
{
cfg.Host(_config.ServiceBusUri, host => {
host.SharedAccessSignature(s =>
{
s.KeyName = _config.KeyName;
s.SharedAccessKey = _config.SharedAccessKey;
s.TokenTimeToLive = TimeSpan.FromDays(1);
s.TokenScope = TokenScope.Namespace;
});
});
cfg.ReceiveEndpoint("publish", ec =>
{
// this is done to register all consumers in the assembly and to use their definition files
ec.ConfigureConsumers(provider);
});
And my handler definition in the consumer (an azure worker service)
public class CreateAccessPointCommandHandlerDef : ConsumerDefinition<CreateAccessPointCommandHandler>
{
public CreateAccessPointCommandHandlerDef()
{
EndpointName = "specific";
ConcurrentMessageLimit = 4;
}
protected override void ConfigureConsumer(
IReceiveEndpointConfigurator endpointConfigurator,
IConsumerConfigurator<CreateAccessPointCommandHandler> consumerConfigurator
)
{
endpointConfigurator.UseMessageRetry(r =>
{
r.Immediate(2);
});
}
}
In my app that is sending the message I have to configure it to send to the "publish" queue, not "specific".
EndpointConvention.Map<CreateAccessPointsCommand>(new Uri($"queue:specific")); // does not work
EndpointConvention.Map<CreateAccessPointsCommand>(new Uri($"queue:publish")); // this does work
Because you are configuring the receive endpoint yourself, and giving it the name publish, that's the receive endpoint.
To configure the endpoints using the definitions, use:
cfg.ConfigureEndpoints(provider);
This will use the definitions that were registered in the container to configure the receive endpoints, using the consumer endpoint name defined.
This is also explained in the documentation.
I am having fun with using moleculer-runner instead of creating a ServiceBroker instance in a moleculer-web project I am working on. The Runner simplifies setting up services for moleculer-web, and all the services - including the api.service.js file - look and behave the same, using a module.exports = { blah } format.
I can cleanly define the REST endpoints in the api.service.js file, and create the connected functions in the appropriate service files. For example aliases: { 'GET sensors': 'sensors.list' } points to the list() action/function in sensors.service.js . It all works great using some dummy data in an array.
The next step is to get the service(s) to open up a socket and talk to a local program listening on an internal set address/port. The idea is to accept a REST call from the web, talk to a local program over a socket to get some data, then format and return the data back via REST to the client.
BUT When I want to use sockets with moleculer, I'm having trouble finding useful info and examples on integrating moleculer-io with a moleculer-runner-based setup. All the examples I find use the ServiceBroker model. I thought my Google-Fu was pretty good, but I'm at a loss as to where to look to next. Or, can i modify the ServiceBroker examples to work with moleculer-runner? Any insight or input is welcome.
If you want the following chain:
localhost:3000/sensor/list -> sensor.list() -> send message to local program:8071 -> get response -> send response as return message to the REST caller.
Then you need to add a socket io client to your sensor service (which has the list() action). Adding a client will allow it to communicate with "outside world" via sockets.
Check the image below. I think it has everything that you need.
As a skeleton I've used moleculer-demo project.
What I have:
API service api.service.js. That handles the HTTP requests and passes them to the sensor.service.js
The sensor.service.js will be responsible for communicating with remote socket.io server so it needs to have a socket.io client. Now, when the sensor.service.js service has started() I'm establishing a connection with a remote server located at port 8071. After this I can use this connection in my service actions to communicate with socket.io server. This is exactly what I'm doing in sensor.list action.
I've also created remote-server.service.js to mock your socket.io server. Despite being a moleculer service, the sensor.service.js communicates with it via socket.io protocol.
It doesn't matter if your services use (or not) socket.io. All the services are declared in the same way, i.e., module.exports = {}
Below is a working example with socket.io.
const { ServiceBroker } = require("moleculer");
const ApiGateway = require("moleculer-web");
const SocketIOService = require("moleculer-io");
const io = require("socket.io-client");
const IOService = {
name: "api",
// SocketIOService should be after moleculer-web
// Load the HTTP API Gateway to be able to reach "greeter" action via:
// http://localhost:3000/hello/greeter
mixins: [ApiGateway, SocketIOService]
};
const HelloService = {
name: "hello",
actions: {
greeter() {
return "Hello Via Socket";
}
}
};
const broker = new ServiceBroker();
broker.createService(IOService);
broker.createService(HelloService);
broker.start().then(async () => {
const socket = io("http://localhost:3000", {
reconnectionDelay: 300,
reconnectionDelayMax: 300
});
socket.on("connect", () => {
console.log("Connection with the Gateway established");
});
socket.emit("call", "hello.greeter", (error, res) => {
console.log(res);
});
});
To make it work with moleculer-runner just copy the service declarations into my-service.service.js. So for example, your api.service.js could look like:
// api.service.js
module.exports = {
name: "api",
// SocketIOService should be after moleculer-web
// Load the HTTP API Gateway to be able to reach "greeter" action via:
// http://localhost:3000/hello/greeter
mixins: [ApiGateway, SocketIOService]
}
and your greeter service:
// greeter.service.js
module.exports = {
name: "hello",
actions: {
greeter() {
return "Hello Via Socket";
}
}
}
And run npm run dev or moleculer-runner --repl --hot services
I have a question about WebSocket based on Jetty. Is there any way to capture the parameters companied with client side connect to Jetty Server side?
It looks like the following sample code:
Client :
javascript -
ws = new WebSocket("ws://localhost/events/member=12345");
Server :
#OnWebSocketConnect
public void onConnect(Session session, String member) {
// member will get "12345"
System.out.println(member);
}