CODEWITHSUNDEEP
debuggingmicrosoft-teamsngrok
user3224132
user3224132

Reputation: 1

Debug MS Teams application without ngrok?

I am working on MS Teams development. I installed the MS Teams toolkit in VS Code, set up my subscription with Azure and sideloading is active in my tenant.

When I run the app, it tries to install ngrok. This step fails as my organization does not allow running ngrok or other words tunnelling from our company laptop. We can run this on a VM to go around this but VM is not always available.

I am looking for a resolution for below scenarios:

  1. Is there a way to debug MS Teams application without ngrok?
  2. If we need a https URL, is it possible to configure a web app to facilitate that?

I tried removing install ngrok step from: /.vscode/tasks.json, but there are subsequent steps it the file dependent on that

Upvotes: 0

Views: 822

Answers (2)

WerkmanW
WerkmanW

Reputation: 102

I've done quite a bit of research on this question myself as I'd been getting a lot of pushback from our IT department regarding the security threats that come with using a tunneling service like ngrok. It eventually led me to this video posted on the MS forums from a Microsoft engineer who explains it clearly.

What it comes down to is that the Teams client (browser/desktop) approaches webservices (configured in the manifest file) differently depending on the type of interaction. If you're testing configurable tabs, task modules or configuration pages, then you can easily route the app to those sites running on your localhost through the manifest. The Teams client will approach them directly. Problems start to arise when you want to debug what happens when you use a bot or message extension, outgoing webhook or MS Graph change notifications (just quoting the video here, there might be other scenarios).

Basically, what happens is that the Teams client goes through a Microsoft-hosted service first, called Microsoft Teams Services, which will then approach your bot framework cloud service (typically an Azure Bot resource). This then forwards any incoming messages to whatever endpoint you have configured. What happens in these separate stages isn't completely clear to me, but what I do know is that whatever is typed by the user in the Teams client is translated to a JSON structure that can be interpreted by your server-side bot code (for C# apps, this is typically your CloudAdapter-derived class working with your TeamsBot-derived class). These messages are then routed to the relevant TeamsBot class method based on properties in the JSON.

Now the issue that ngrok solves is that, when the Teams client goes onto the public internet to reach the MS Teams Services server and then the Azure Bot resource, it then needs a public address to route the traffic to. It doesn't know about your local network anymore. As ngrok sets up a TCP tunnel between their server and your local PC, it is able to route traffic coming to their server to your PC. The Azure Bot now has a public address to send the messages to.

To my knowledge, there is no way to circumvent this as long as Teams client inner workings always make it go outside of your local network. For chat scenarios, the Bot Framework Emulator might offer a solution for unit testing. As far as I can see it performs the translation of chat input to the JSON message model of the Bot Framework and routes it to a local address for your chatbot to process it. Unfortunately, this doesn't work for chat message extension type messages.

As for the question whether ngrok can be avoided, I think the answer is definitely yes but you would need an alternative. There's several alternatives around that you might be able to host yourself if you have the technical know-how. Depending on your IT department, being in control of the public-internet-facing server might be a more viable solution for them. Another option is to host ngrok on a VM or cloud machine with less access to your internal network's resources than your PC/laptop has and test the code there.

TL;DR: If the the feature you're testing is approached directly by the Teams client, you can enter localhost in the manifest and debug it. If you're testing a feature that the teams client approaches through Microsoft Teams Services and the Bot Framework, you need to find a way to expose your code to the public internet. You can use ngrok or host your own alternative depending on requirements.

Upvotes: 2

tauzN
tauzN

Reputation: 6931

  1. use mkcert to generate a certificate for ex. localhost.test
  2. add losthost.test to your host file
  3. use https://localhost.test for debugging

Upvotes: 0

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