Stamp Specific endpoint changes

[kryalama]

Overview

• Ingestion endpoint redirects incoming requests where URL doesn’t match the IngestionEndpoint of a given ikey. For requests with a single ikey, Breeze sends back 308 (permanent redirect) response code with a Location header specifying the URL where the client should send the data instead. For requests with multiple ikeys, Breeze sends back 206 (partial content) response code with the redirection URLs embedded in the response body.(Partial redirects is not a valid scenario for Web JS SDK)
• SDKs will post requests to the new /v2.1/track query path to indicate support for redirects from Breeze. (work in progress from Ingestion side)
• SDKs will follow up to 10 redirects (to prevent circular redirects)

Internal Change spec

//TODO

1. Once we have the new api ' /v2.1/track' available , make necessary updates to SDK.
2. Add unit tests if possible
3. Once Breeze have the ability to accept query parameter 'redirect=false', update the beacon API code and the snippet code to call the new url with redirect=false parameter.

[MSNev]

Note: it looks like the test pass failed for the same issue I talked about in standup today.

My PR #1469 has the temporary fix for this -- it's a bit big though, but if you have a chance to review would be good.

[MSNev]

Probably should check that

• the responseURL is not empty and look valid (some XHR polyfill's might not set this etc)

Additional considerations.

• Do we want to retry the original URL if the redirected one also continues to fail
• Do we only want to update on a successful send (200-299 response status code)

[kryalama]

I think updating the url only after we get a successful xhr send is a better approach.

[MSNev]

Note: it looks like the test pass failed for the same issue I talked about in standup today.

Fixes for the test failures (dts generation) are now checked in, to rebasing should resolve the test issues

[MSNev]

What's the timeframe for this todo?