Why doesn't #RolesAllowed of JAAS work i.e. why there is no exception when an unauthorized websocket request comes to the server. If the same request is an ajax request it works perfectly!
I am using grizzly websockets and glassfish server.
In Glassfish3 WebSocket requests come to user WebSocketApplication directly bypassing web container. I think this is the reason why #RolesAllowed is ignored. You can try Glassfish4 + standard WebSocket API, I think #RolesAllowed should work there.
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I'm trying to connect to a grpc-service from a Java client. The problem is that this service is currently supporting only grpc-web over http1.1, this is because of a limitation of supporting http2 in Azure App service where the service is deployed.
The grpc-java client liberary from io.grpc only supports grpc over http2 protocol, which maskes sense, and unfortenatly is not working for me.
I managed to consume a service using HTTP client from apache and okhttp3 but this works for unary calls and it didn't work for a server-side streaming service.
Is any one aware of a grpc-web java client liberary that I could use or a work arround using convenienal Http for reading grpc-web server-side streaming service.
If I understand your question correctly, you want a Java client for gRPC-Web so that your client can talk HTTP/1.1 through a gRPC-Web proxy (e.g. Envoy gRPC-Web) because you're unable to talk HTTP/2 directly to your service because of the Azure networking limitation?
In theory this should be possible. The JavaScript implementation is because, in-browser, there's no alternative except JSON transcoding. The JavaScript implementation does implement server-side streaming, which is another requirement and confirms that this should be possible over HTTP/1.1.
However, in a quick search I found no other (i.e non-JavaScript) client implementations of gRPC-Web.
I have an application running behind a Load Balancer in Google Cloud Platform.
When I use the HTTPS protocol in the backend, I'm able to connect with WebSockets and all WebSocket connections work fine. However, when I change the backend protocol to HTTP/2, I'm unable to connect from the application, and it returns a response of 502 Bad Gateway.
Can I use WebSockets with HTTP/2, or do I need to perform some configuration in order to use WebSockets with an HTTP2 backend?
As others have commented, WebSockets are not supported in HTTP/2 and this is the reason why you receive the 5XX error.
Having said that, the WebSocket functionality is achievable (and improved) with HTTP/2 ref.
If you have existing code working with WebSocket it might not be great to rewrite both backend and frontend.
However, if you are developing a new asynchronous service, it is a good idea to take a look at the HTTP/2 + Server Sent Event (SSE) scheme.
I'm newbie of grpc and have played with simple grpc clients of java, go, and python. I know basic http and https but not familiar with protocal details. So this question may be rediculous to you but I didn't find any explaination online.
I know grpc has insecure(go: grpc.WithInsecure(), python: grpc.insecure_channel, java: usePlaintext()) and secure mode(TLS). and grpc is based on httpv2, and http has security mode(https).
So what if use insecure grpc with https? Is the overall data transfer safe?
And what if use TLS grpc with https? Is there performance overhead(becuase I think the messages are encrypted twice)?
Thank you for any answer, any exsiting webpages explaining such topic that will be best!
Insecure implies http. And TLS implies https. So there's no way "to use insecure grpc with https", as at that point it is then http.
There is no double-encryption. The gRPC security mode is the same as the HTTP security mode.
Using gRPC over TLS is highly recommended if you gRPC server is serving requests coming from outside(external network). For example you're creating front end app in javascript serving user requests. Your javascript app make call to your gRPC server for APIs your server provide. Your javascript communicate to your gRPC server through stub created in javascript end. At the end of your gRPC server, you need to set tls mechanism to secure communication between your javascript app and your gRPC server(because requests coming from outside).
gRPC somehow mostly used for internal services communication inside internal network in microservice architecture. You don't need to set tls for internal network usage since requests coming from your own environment from within your watch.
If you want to apply something like "gRPC over HTTPS", then you need something like gateway to map your http call to your gRPC server. Check this out.
You need to compile your proto file as gateway service definitions as well using provided tools. Now you can create your normal http server with tls enabled through something like http.ListenAndServeTLS(...). Dont forget to register your grpc server to the http server using the service definitions compiled from the proto file. With this all your requests to are encrypted with tls to your http server like normal rest apis do, but get proxied to gRPC server you defined. There's no need to enable tls at your gRPC server since it has been enabled in your http server.
When an http connection is upgraded to a websocket connection can my javascript code still use http ajax GET requests for example? That is, I can do both normal http requests and websocket messages or does "upgraded to websocket" mean the http capabilities are gone?
If your server supports both normal web requests and WebSocket upgrades (some servers are either one or the other), then you can continue to make AJAX requests even while you have a WebSocket connection. AJAX (XMLHttpRequest) requests are just regular HTTP/HTTPS requests that are initiated by Javascript rather than by the browser when the page loads. Having an active WebSocket connection will not interfere with other HTTP/HTTPS (or AJAX) connections. Unless of course the server has a bug.
Web-servers work in response to incoming HTTP requests... process the request and return an HTTP response. Are there any common ways that a server can PUSH data to clients in this architecture... e.g a request comes in from client1 and the server wants to notify client2? It can obviously be done by a non-web server, using sockets, but what about a web-server app which has to support page requests AND allow PUSHing data..?
what about a web-server app which has to support page requests AND allow PUSHing data..?
Servlet 3.0 introduces Async support allowing to write Comet style applications (i.e. applications using Long-lived HTTP connections and either long polling or streaming).
If you can't wait for Servlet 3.0 Async support and don't want to use proprietary Comet or WebSocket support from containers (like GlassFish, Jetty), then have a look at Atmosphere.
See also
JavaOne 2008: Comet (AJAX, Grizzly and Cometd)
Asynchronous processing support in Servlet 3.0
Servlet 3.0 Async API or Atmosphere? A Simple Comparison
You can use web app containers like Jetty which support Web Sockets if you don't mind waiting for the web world to catch up to this up-and-coming standard. Then you'll have real bi-directional communications instead of HTTP + Polling or special plug-ins or the like.
No, not without some client side tech (Flash, Silverlight, Applets, etc.)
You could have the page poll the server with AJAX though.
Another possibility would be to abuse HTTP Keep Alive to achieve this. See http://en.wikipedia.org/wiki/HTTP_persistent_connection for some background. In your scenario you would have client2 initiate a connection to the server that then would stay open listening for notifications.
This is not a great solution, first off you need to keep lots of long lived TCP connections around, and if a connection is lost there is no way for the server to reconnect. It must wait for the client to come back.