I have an express js client app and an express server app with almost the same istio configuration. Client cannot be accessed through its host URL while the server is working well. Curl client host URL just gives me infinite waiting. And I cannot find any related traffic log in the istio-proxy of client pod. This is very confusing. What could be the possible reason for this problem?
istioctl analyse on live cluster dose not give any helpful information
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For network gurus out there, I'll like to ask some questions regarding some unique setup where the server will be sending a request to a client on localhost on a certain port.
I have a cloudy understanding of some network fundamentals that I hope you'll be able to help me out.
Kindly check the image below:
Basically, there's a static website hosted in AWS s3 and at some point this website will send a request to https://localhost:8001.
I was expecting that it will connect to the nginx container listening on port 8001 in my local machine, but it results in 504 gateway error.
My questions are:
Is it possible for a remote server to directly send data to a client at a particular port by addressing it as localhost?
How is it possible for the static website to communicate to my local docker container?
Thanks in advance.
In the setup you show, in the context of a Web site, localhost isn't in your picture at all. It's the desktop machine running the end user's Web browser.
More generally, you show several boxes in your diagram – "local machine", "Docker VM", "individual container", "server in Amazon's data center" – and within each of these boxes, if they make an outbound request to localhost, it reaches back to itself.
You have two basic options here:
(1) Set up a separate (Route 53) DNS name for your back-end service, and use that https://backend.example.com/... host name in your front-end application.
(2) Set up an HTTP reverse proxy that forwards /, /assets, ... to S3, and /api to the back-end service. In your front-end application use only the HTTP path with no host name at all.
The second option is more work to set up, but once you've set it up, it's much easier to develop code for. Webpack has a similar "proxy the backend" option for day-to-day development. This setup means the front-end application itself doesn't care where it's running, and you don't need to rebuild the application if the URL changes (or an individual developer needs to run it on their local system).
Have created a chatbot and I am trying to connect it to my local host using ngrok....the localjost is running via my computer and is showing active...however dialogflow webhook is not able to send any request to the ngrok portal...
I have tried multiple time to host a server via ngrok and pasted the link in webhook section in Dialogflow..but dialogflow diagnostic shows
Webhook call failed. Error: PERMISSION_DENIED.
fulfillment status ngrok cmd prompt ngrok server
Any help would be appreciated...not sure what I am missing....
Without seeing the actual configuration, there are a few things I would look at:
Make sure you're actually using the right ngrok URL from your console. Many times I was using an older URL in the Dialogflow configuration.
Make sure you're using the HTTPS URL.
Make sure your server is actually running on your computer, and that it is listening at the same port that ngrok is using on your computer.
Check the ngrok console to see if it is getting the request at all and what the response might be.
Go to http://localhost:4040/ which will give you details of each connection through ngrok.
I'm trying to create a web app on AWS and I'm running into port issues. I would like to have multiple apps providing different services on different ports. I've created a website (on the same instance) to receive a text query and pass it to my app on port 3000. The app listening on 3000 is written in CherryPy.
We are using a VPN to provide security for the AWS instance. When logged into the VPN, everything works fine. The web page loads, the query returns the correct data. When I disconnect from the VPN, or someone else goes to the page, the page still loads, but queries to the service time out.
I've used netstat to make sure the service is listening but I'm not sure what could be blocking traffic. I've worked through the CORS issues as evident by the fact it works when I'm signed into the VPN.
What can I check now?
When I disconnect from the VPN, or someone else goes to the page, the page still loads, but queries to the service time out.
My assumption is that the web server and the app are on the same server.
It sounds very much like the connection from web server to app is happening via a routed IP address rather than localhost. In addition to being slower, it's also hitting your firewall rules.
Configure the web server to access your app on localhost:3000 and the issue should clear up.
I actually got it working. I have an AWS instance with nginix and CherryPy. When the user goes to a web address, the nginix page loads with a form for a query string. When they submit a string, the string is POSTed to a CherryPy service running on port 3000. The CherryPy service does some computations and returns a result via JSON.
I thought I had opened up everything completely for testing, but I was having so many issues. It turned out that having CherryPy set
"Access-Control-Allow-Origin" = "*"
wasn't working, instead I needed to specifically set the origin of the calling page.
We are upgrading from 10.0 to 10.3.6. Our web app is running in a DMZ and uses .jar files created with clientgen to invoke JAX-RPC web service operations deployed on our internal network by going through an XML firewall. My problem is that the XML firewall is behaving as though the HTTP request to invoke the web service operation was sent twice, when as near as I can tell it was only sent once. I set the following properties to view the soap traffic:
-Dweblogic.wsee.verbose=*
-Dweblogic.log.RedirectStdoutToServerLogEnabled=true
Unfortunately I don't have access to the XML firewall but I have been able to get the log entires for my service endpoints. I can see that it reports receiving duplicate requests but for the life of me I don't know how this can be happening. This does not happen when the web service clients are running on version 10.0.
I've tried everything I can think of to troubleshoot this problem. I'm hoping somebody here can offer up some suggestions or perhaps tell me if this is a known issue.
You could use TCP Monitor to intercept the SOAP traffic between your server and the firewall.
This way you can tell if the requests are being sent twice or if there is some internal issue with the firewall.
Also, after you intercept the requests, you can use again TCP Monitor or SOAP UI to re-send the request to emulate the webserver and debug the firewall.
I've a simple jax-ws web service that on localhost works fine with the clients, but now I want to publish the web service on a public ip, so the clients can interact with it through wan network instead lan network.
I signed to no-ip dns service provider and defined my host like "myname.no-ip.info".
In my code i start the service in this way:
Endpoint.publish("http://localhost:8080/baseStationProvider", new BaseStationProvider());
and the browser at http://myname.no-ip.info:8080/baseStationProvider#wsdl doesn't show the wsdl.
If i start the service in this way:
Endpoint.publish("http://myname.no-ip.info/baseStationProvider", new BaseStationProvider());
compiling the code, it raise this exception:
Server Runtime Error: java.net.SocketException: Unresolved address
Any idea to problem and/or how to do what i need?
thanks in advance
This seems likely to do with routing and firewalls as opposed to web service publication etc. Ignoring the web-service aspect, can you even reach your server when you use this in your browser:
http://myname.no-ip.info:8080/
?
Which should look the same as
http://localhost:8080/
If not, then it is probably DNS/Routing/Firewalls that you need to check. Diagnostics that will help there are:
1) can the machine you are testing on resolve the DNS name mynam.no-ip.info? nslookup, ping, traceroute/tracert
2) is there a firewall blocking port 8080 from reaching local host? If the route from the internet to your host hits a firewall (which it will) that firewall will have to forward the request.
Good luck.