I do not have a choice of installing a network traffic analyzer.
How would I go about looking at the response from chrome to a websocket's ping frame.
In chrome dev tools, it seems we can only see the incoming frames.
Background: I am trying to develop a websocket java client, but the server sends a close soon after a ping, I am assuming this is because of lack of response from the client. I have tried responding with a "pong" and 0xA byte, but still the connection is closed.
Related
I am writing a web server, specifically, a server that handles HTTP/1.0 and HTTP/1.1 protocols. I implemented HTTP/1.0 features in my server and wanted to look at persistent HTTP connections (Connection: Keep-Alive). I also implemented that feature and tested the server via telnet. Everything works fine for telnet, the server does not close the client socket after every request, waits for 15 seconds, and closes the socket if it is inactive.
To ensure that it works correctly, I re-tested the server with Postman. Here is the screenshot:
As you can see from the logs, the socket connection is not dropped after sending the response. After 15 seconds of inactivity, the server closes the socket. This is the desired behavior
However, when I used the Google Chrome web browser, it turns out that it does not work correctly (not the same with the desired behavior). Here is the screenshot:
I speculate that Google Chrome creates a new socket connection for every request even though Connection: Keep-Alive is present in both HTTP request/response messages. However, I am not sure whether this is true or not. By the way, I also used Safari and the output is the same.
Is this the reason why persistent HTTP connection does not work in Google, yet it works with telnet and Postman?
Thanks
I'm looking for a way to forward websocket traffic that is received by a standard Chrome instance on Windows.
Eg. On a website that establishes a WS session. As the frames come in from the server, I want to relay / forward them to a service on my local network. I'd also want the browser to receive as normal.
Is there a way to do this within Chrome or via an extension? If not, I am assuming best option to to set up a proxy server?
Any other ideas /suggestions appreciated
Thanks
How to revive HttpClient and make it see that the network is available again without fully restarting the application?
In case when a Xamarin.Forms app was launched with no network connection available and then later network connection is enabled, HttpClient.SendAsync(request) throws NameResolutionFailure and it does not recover, no matter how many times the request is repeated.
It seems, HttpClient does not know how to recover when network connection appears.
To reproduce the issue in Android emulator:
ensure your app is completely closed
turn network off (set Data status to Roaming in emulator settings or use the status bar to toggle the data or LTE switch).
launch your app, run a web request to verify that it does not work (obviously, you will need try/catch around the web request to avoid crashing)
while the app is still open, enable the network
run a web request - will get NameResolutionFailure
only full application restart will revive HttpClient
The issue does not happen if I use domain names specified in etc/hosts file.
I tried to fully recreate HttpClient and resend a new request when the issue occurs, but that does not help. Only full restart of the app helps.
Obviously, I cannot ask user to fully kill my app and start it again every time when user has turned on his network connection after launching my app.
This is a known issue. See:
Mono: https://bugzilla.xamarin.com/show_bug.cgi?id=45761
iOS: https://bugzilla.xamarin.com/show_bug.cgi?id=45763
Android: https://bugzilla.xamarin.com/show_bug.cgi?id=45383
The workaround is to manually set the DNS refresh:
System.Net.ServicePointManager.DnsRefreshTimeout = 0;
In the context of a unit test I need to send some code to the console of a chrome app I am developing. It's clear that I can do that from the chrome.debug API, but is there a way to do that from outside the browser?
Yes, there is a way; if you can do something with chrome.debug you can do so with remote debugging.
You need to enable remote debugging with command line switches; you can then connect to Chrome with a debugger client instance.
Google lists some existing debugger clients, and you can implement your own by following the debugger protocol (which works over HTTP+WebSockets).
The procedure for a debugger client is to request /json from the debugger port over HTTP, which lists all possible debug targets; the client then connects to the WebSocket associated with that target to work with it.
I am trying to get a simple web page server from within a Google Chrome Packaged App. There is already a UDP server running within the app and working without any problems.
I am starting the socket.listen on 0.0.0.0:8080 and copying most of the code from
https://github.com/GoogleChrome/chrome-app-samples/tree/master/webserver
. The same issue is replicated in the sample app.
What I am doing is accepting the request and sending a single HTML file to all requests which have some data in the request (request.data.length > 0). The flow of the app is similar to the sample app with near-equivalent functions.
To test this I am using Socket Test 3.0 (from SourceForge). Creating a socket to 127.0.0.1:8080 and sending it GET / HTTP/1.1 as the content. As intended the Chrome App responds with the html file and correct headers. I can repeat this multiple times without restarting the App. The problem arises when the App is sent a request through Chrome. On first look it works as intended, but then it Time Out on refresh. This is also replicated in the sample app.
On debugging I found that every thing was being handles. The write socket being destroyed and a socket.accept(serverSocket, ...) being issued. I also made sure that it was done inside the callback function of the socket.write. The first request as intended is for the page requested (GET / HTTP/1.1 for localhost:8080). Second was for favicon.ico as GET /favicon.ico HTTP/1.1. And then a third connection with none in data (which is then ignored and socket destroyed). Unlike in the SocketTest where every request was answered back.
I have created a video showing the screencast while reproducing the error on YouTube. Also the repo for the project that I'm working on is at GitHub.
I had the same issues with Google's sample web server. I wrote a more robust socket server app that does not hang. The source is on GitHub at https://github.com/kzahel/web-server-chrome and you can install it from the Chrome web store at https://chrome.google.com/webstore/detail/web-server-for-chrome/ofhbbkphhbklhfoeikjpcbhemlocgigb