I have .net core API inside the web app and that web app is backend pool for azure application gateway. while trying to access the web app got below error.
"502 - Web server received an invalid response while acting as a gateway or proxy server."
On app GW, health prob for that web app in unhealthy but while access the API as a https://abc.azurewebsites.net/api/values then it works.
When we deploy API in Web App Service then apiname.azurewebsites.net does not work give any probes to application gateway and treat unhealthy. API works like xxx.azurewebsites.net/api/values and Application Gateway also know this path. We have to put /api/values in override backend path of http settings. Same have to do in health probes.
Yes, you can first verify if the backend API could access directly without app gateway. Then this error may happen due to the following main reasons:
NSG, UDR or Custom DNS is blocking access to backend pool members.
Back-end VMs or instances of virtual machine scale set are not responding to the default health probe.
Invalid or improper configuration of custom health probes.
Azure Application Gateway's back-end pool is not configured or empty.
None of the VMs or instances in virtual machine scale set are healthy.
Request time-out or connectivity issues with user requests.
Generally, the Backend healthy status and details could point it out and show some clues. You could also verify all of the above reasons one by one according to this DOC.
Related
In my AWS remote Desktop, I have hosted my web application and API service application using IIS(internet information service). In that, Application pools stopped my API service in remote desktop IIS at every midnight of lesser usage time. In the morning always I restart my API services in IIS then it works fine. I need a permanent solution to fix this problem always API service will be in Up. Please suggest your solution.Attachment for reference
I am working on a Blazor(PWA) standalone app. Is deploying to a hosting provider required for standalone Blazor webassembly PWA? Or is it possible to serve the app from a network location for users to download and run it locally in their browser? I looked for documentation but can't find any. Please let me know. Thanks!
You'll need to host the app from an HTTP server that provides secure hosting (HTTPS). For example, you could set up an HTTP server on your local network, or use a hosting provider on the internet.
It cannot be shared from a network drive, or anything like that because it's not considered secure, and thus the service worker won't be registered.
I'm having an issue with a project I'm working on. I have a Vue client which does API calls to my backend which is written in .NET Core 3.1. Both these applications are deployed on diffent servers.
Now the problem is that my backend server does not allow me to do API calls straight from the browser. So I have to do some kind of 'redirect' on the client server to reach my API.
So for example:
If I call backend_server/api/values I get an error (Firewall).
I think I should make like a second API or something, but I'm not sure how to handle this issue.
Does anybody have any experience on this? Any help is welcome!
Kind regards
You can have multiple options here
Remove the firewall rule -
This will allow your API to get hit from browser. If firewall is not managed by you you can't do this
Add IP or Port exception rule in firewall -
Instead of deactivating the entire inbound rule on server, you can allow specific ports or IP on firewall. Again if you have control on firewall
Create Proxy API -
Another way is you can create a middleware API that forwards your request and acts as a proxy. This will suffice performance, resource, time and compromise security. I recommend not to do this, But it's easily possible in .NET Core
Specify CORS policy -
If your Vue.js and API originates from same origin (IP), You can configure CORS in server which will restrict access to API only from same origin. That means only www.google.com can access GoogleAPI, Likewise. This will protect the API from other origins
Tunnel via VPN -
If security is a concern, Use a VPN service to tunnel your API requests. This can't be possible for every client using your web service.
The best way is to open a specific rule on server for your application if possible. Writing a proxy in between will have lot of disadvantages although can be accomplished.
I am accessing a third party web api from my WCF application. While development I was able to access those APIs but when I deployed my WCF to IIS, its not able to connect to the web API and throwing me the following error:
"System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it X.X.X.X:443"
Just to make sure that my server is fine where I deployed my WCF. I tried accessing those web api from a simple console application. It accessed those apis from my development machine and from the server machine as well. Now I feel the culprit is not the third party web api server, but something goes wrong when a WCF service access' a web-api hosted in IIS.
Please help!!!
Finally I found the issue. IIS runs my WCF under user 'network service' or 'application pool identity'. These are nothing but window built-in users which has limited access. When I tried accessing third party API from the console application it worked because it was running under my user credential which has admin credential. So I concluded that when an application making cross-domain call then it should be running under a user with enough credential to make such calls.
Solution was to change my application pool identity to a admin user identity (I changed it to my logged in user). It worked and making calls to third party API from WCF service
I have two separate projects
MVC Web App
MVC Web API
I have published both on my IIS 7.5
My Web App is hosted on 7172 port
and Web API is hosted on 7171 port
Strangely iam not able to call jquery.ajax() from my web app (7172) to web api (7171) port. It gives me 405 Method not found error code.
But if i write the same jquery.ajax() in my web api project (7171) and call web api method then it work fine and returns data.
I want to call web api from my web app.
Any suggestion would be appreciated.
Thanks in advance.
This has to do with the Same Origin Policy. By default, you can't execute an AJAX call to another domain (both on name, port and protocol).
If you want to enable this you should use Cross-origin resource sharing (CORS). CORS can be used with Web API by installing a (prerelase) NuGet package: Microsoft ASP.NET Web API Cross-Origin Support
This package allows you to configure which domains can call your service. You can find a walk trough here Enabling Cross-Origin Requests in ASP.NET Web API. In essence it comes down to adding attributes to your controllers like this:
[EnableCors(origins: "http://myclient.azurewebsites.net", headers: "*", methods: "*")]
You're running into the same-origin/cross-domain security policy. The port used is part of the origin calculation. A bit of Javascript loaded from (say) localhost:80 cannot make an AJAX request to localhost:8080, because the port numbers don't match. The 405 error you're getting is almost certainly coming from your Web App, not the API - check the server logs for the app, and you'll see the ajax hit in there.