Unable to Connect Through Corporate Proxy- No User-Agent String Provided to Allow

[Darian-FRB]

Our developers are working behind a corporate proxy server. All user-agent strings are denied by default with only approved client browser applications approved to pass through the proxy.

When attempting to connect to Azure using the Azure Resources extension in Visual Studio Code, access beyond the proxy is denied. We are not able to allow the extension through our proxy because there is no user-agent string provided, it is blank.

Please update the extension so that when it makes web requests a user-agent string is provided to identify the client source of the traffic. Once there is a user-agent string we will be able to put in a request to allow the extension through our corporate proxy.

As a workaround, we are using the Fiddler Classic development proxy to impersonate allowed user-agent strings.

[alexweininger]

Hi @Darian-FRB, can you identify which requests don't have user-agent strings?

[Darian-FRB]

Hi @alexweininger, I am no longer able to reproduce the issue with Fiddler due to environmental circumstances.

At the time I was last able to reproduce the issue the proxy's web page error reported:
User Agent:
URL: tcp://vscode.dev:443/

When testing today, per our proxy logs, it appears to be with the destination default.exp-tas.com.

I discussed this with our proxy administrator. He can set the proxy to allow traffic to this destination if it is the culprit. I would need a brief explanation of what default.exp-tas.com is used for.

[alexweininger]

The default.exp-tas.com domain is likely some extensions accessing VS Code's A/B test API. https://default.exp-tas.com/vscode/ab

[Darian-FRB]

From a clean install of VS Code, the only extension is Azure Resources. VS Code may be using default.exp-tas.com itself. I am also seeing Google Analytics traffic, but that is another matter. May I ask which domains/APIs/protocols the extension is supposed to use for authentication?