[Internal] Thin Client Integration: Adds HTTP Client Sharing between Gateway and Thin Client

[aavasthy]

Pull Request Template

Description

Adding HttpClient sharing logic between Gateway and Thinclient model. HttpClient is capable of handling both Http1.1 and Http2.0 protocol. The request will decide which protocol to use based on the connection mode.

Therefore, ideally it should be possible to share the same client with both the (Gateway and Thin Client) store models.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Closing issues

To automatically close an issue: closes #4579

[FabianMeiswinkel]

LGTM - I was initially sceptical whether sharing HttpClient between normal Gateway (possibly HTTP 1.1) and ThinClient is a good idea. But trying to poke holes in that idea I don't see any obvious problem. If customer configures HttpClient to not allow HTTP/2 seeing failures for ThinClient is expected i guess. You could mess-up the normal Gateway HttpClient if something goes wrong with ThinClient - but this is something we can properly test.

[aavasthy]

LGTM - I was initially sceptical whether sharing HttpClient between normal Gateway (possibly HTTP 1.1) and ThinClient is a good idea. But trying to poke holes in that idea I don't see any obvious problem. If customer configures HttpClient to not allow HTTP/2 seeing failures for ThinClient is expected i guess. You could mess-up the normal Gateway HttpClient if something goes wrong with ThinClient - but this is something we can properly test.

Tested these changes with both gateway mode and thinclient mode by enabling and disabling thinclient flag. For regression, I am relying on existing pipeline tests we have. Is there anything else we should cover as part of testing this change?