Teams Tab App Cannot Reach server

[George71]

Hi,

I’ve been trying to host my Teams tab app using Tomcat on the same PC where Teams is running (i.e. localhost) with TLS enabled but I can’t seem to get it to work. Teams cannot display a simple page with HTML.

I know Tomcat is working  because I can display a page using a web browser with “https”.  I also know Teams can display a page with “https” because I can use Tomcat without TLS enabled and then map the “https” requests to “http” using ngrok.

My Teams app is hosted on port 443. Is the right port for a Teams app? I also configured the the manifest file with:

"staticTabs":[{ . . . "contentUrl": "https://localhost/gctest/index2.html", . . .}],
"validDomains": ["localhost"]

I also tried replacing "localhost" and something else that was mapped to 127.0.0.1 in my Windows hosts file but that did not work either. Is there something I need to configure in the manifest.json file and/or Azure AD to get this to work?

I used the Wireshark application to capture the packets. I'm seeing the "Encrypted Alert" message:

Does this indicate a problem with my Teams app configuration?

Thanks!

George

[#2 · Accepted solution]

@George, Teams doesn't allow local hosting. You'll need to either publish your tab to a public URL, or use a proxy that will expose your local port to an internet-facing URL. Please use ngrok and try the same .

The content url would be like this contentUrl": "ngrokurl/index2.html".

Please refer the doc.

[#3]

Thanks! That would explain why I could not get it to work. :)