fix: Lazy load JWKS

[flaneur2020]

I hereby agree to the terms of the CLA available at: https://databend.rs/dev/policies/cla/

Summary

I runs an integration tests environment which runs a jwks endpoint and databend-query, but in the environment, it's hard to keep the start up order between databend-query and the jwks endpoint.

When databend-query started eariler than the jwks endpoint, it'd panic on start up with the following error:

Databend Query start failure, cause: Code: 1051, displayText = Could not download JWKS: error sending request for url (https://jwks.xxx.svc:8080/.well-known/jwks.json): error trying to connect: dns error: no record found for Query { name: Name("jwks.xxx.svc."), query_type: AAAA, query_class: IN }.

This PR makes the following changes:

• loading JWKS in a lazy manner, makes the JWKS endpoint not a hard requirement for the databend-query's start up
• implement the interval polling JWKS logic in the todo
• removes the async in try_create function and the related callers

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

1 Ignored Deployment

Name	Status	Preview	Updated
databend	⬜️ Ignored (Inspect)		Jan 3, 2023 at 5:06AM (UTC)

[flaneur2020]

@Xuanwo plz help take a look?

[Xuanwo]

Nice change!