fix: Disable the default timeout for requests on the LU build

[benbrown]

Description

This removes the timeout behavior on the /build endpoint, which can result in a network error when publishing a large language model. By default, Node's HTTP server class is set to timeout after 2 minutes.

https://nodejs.org/dist/latest-v6.x/docs/api/http.html#http_server_settimeout_msecs_callback

Task Item

fixes #4294

[a-b-r-o-w-n]

Although this addresses #4294, we should attempt to refactor this endpoint to better fit long processes, like polling or web socket.

[benbrown]

I agree @a-b-r-o-w-n and have a proposal that I will follow up with ASAP.

In short: we already implement a polling procedure for the publishing. I would like to formalize this so that publishing, provisioning, and building can take advantage of the same subsystem.

[a-b-r-o-w-n]

@benbrown that's good to hear.

[cwhitten]

Test environment is failing with:

TypeError: req.setTimeout is not a function

  325 | 
  326 |   // Disable Express' built in 2 minute timeout for requests. Otherwise, large models may fail to build.
> 327 |   req.setTimeout(0, () => {
      |       ^
  328 |     throw new Error('LUIS publish process timed out.');
  329 |   });
  330 | 

Maybe we need to shim this api in the test runner?

[cwhitten]

@benbrown i don't know why tests are failing but it seems specific to this change

[benbrown]

@cwhitten I think I found it. Just pushed a small change to the test.

[coveralls]

Coverage decreased (-0.0004%) to 54.465% when pulling ec026c7 on benbrown/fix4294 into 771af33 on main.