use system props when creating the RestTransport

[fer-marino]

this is a simple pull request that enable the usage of system properties when creating a RestTransport client. This is particularly useful when you need to configure the HTTP client for edge cases, eg. using an http proxy:

-Dhttp.proxyHost=10.250.0.1 -Dhttp.proxyPort=33128

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

[weaviate-git-bot]

To avoid any confusion in the future about your contribution to Weaviate, we work with a Contributor License Agreement. If you agree, you can simply add a comment to this PR that you agree with the CLA so that we can merge.

beep boop - the Weaviate bot 👋🤖

PS:
Are you already a member of the Weaviate Forum?

[bevzzz]

Nice addition, thank you @fer-marino

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Warning	SAST	1   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca

🛡️ The following SAST misconfigurations have been detected

	NAME	FILE
	Prevent Server-Side Request Forgery (SSRF) via User Input in URLs	...ltGrpcTransport.java	View in code

Note: The scan should have failed if no policies were configured in warn-only mode.

[fer-marino]

oh sorry. I've added a lot more stuff. Using an http proxy proved much more difficult than I thought, so here is the implementation. I've also added an extra method for the OIDC authentication to use resourceOwnerPassword providing also a client secret id (needed if anon login is disabled)

[bevzzz]

@fer-marino it's been a busy week, but I'm going to get back to this PR first thing Monday. Appreciate you taking time to contribute!

Using an http proxy proved much more difficult than I thought

Could you please elaborate on the difficulties you ran into with configuring http proxy via system properties? I guess one limitation of that approach would be that it doesn't allow using a different proxy per client. Was there something else you encountered?