Issue 3159: Added support for AzureStackHub and Azure private cloud identification

[schaafito]

Thank you for contributing to Velero!

Please add a summary of your change

Added support for AzureStackHub and private Azure cloud environments by updating the getCloudConfiguration() logic to fall-through to the kubernetes cloud-provider-azure module logic for identifying private cloud environments. This fall-through supports both AZURE_RESOURCE_MANAGER_ENDPOINT cloud discovery as well as AZURE_ENVIRONMENT_FILEPATH discovery.

The private cloud logic can (partially) be tested on any Azure environment by setting the AZURE_CLOUD_NAME to AZURESTACKCLOUD and providing a valid azurestackcloud.json configuration file as documented here. You can set the cloud endpoints to valid endpoints for a public cloud offering to test fallthrough logic.

The bulk of the documentation updates will need to be done on the velero-plugin-for-microsoft-azure project which I plan during the PR cycle to recompile the plugin with these changes. The proposed documentation changes can be seen on my branch

I provided unit tests for both endpoint and filepath cloud discovery, as well as tested in my own Azure environments to confirm functionality.

Note: This feature requires golang1.23 support so I bumped those as well. I see an open PR #8717 which I suspect will need to be merged before this.

Does your change fix a particular issue?

Fixes #3159

Please indicate you've done the following:

• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file (make new-changelog) or comment /kind changelog-not-required on this PR.
• Updated the corresponding documentation in site/content/docs/main.

[anshulahuja98]

@ywk253100 do you have any additional thoughts on this PR?
Overall looks okay to me. I don't have a test environment ready to test this right now.
But I don't anticipate this breaking existing scenarios.

[ywk253100]

Let's rename it as CredentialKeyResourceManagerEndpoint to follow the same pattern with other variables.

[schaafito]

Done!

[ywk253100]

@ywk253100 do you have any additional thoughts on this PR? Overall looks okay to me. I don't have a test environment ready to test this right now. But I don't anticipate this breaking existing scenarios.

I'm OK to the changes.
But let's merge it after 1.16 if it's not a high priority.

[kaovilai]

This is coming from kubernetes-sigs/cloud-provider-azure@5548c42 ("sigs.k8s.io/cloud-provider-azure/pkg/azclient")

Filed issue there to hopefully starve off future unnecessary bumps.

[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.58%. Comparing base (d086cb2) to head (6bfb6ae).
⚠️ Report is 261 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/util/azure/util.go	83.33%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8738      +/-   ##
==========================================
+ Coverage   59.56%   59.58%   +0.01%     
==========================================
  Files         370      370              
  Lines       40229    40246      +17     
==========================================
+ Hits        23964    23981      +17     
  Misses      14766    14766              
  Partials     1499     1499              

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[schaafito]

@anshulahuja98 - I was able to take this branch to an AzureStackHub environment and unfortunately the APIVersion flag didn't work as expected due to the microsoft golang SDK. I opened an issue but until they fix that in the upstream for this to be portable to those disconnected environments we would need a small policy_api_version.go esque implementation. Any concerns if I basically take my sample posted in that issue and implement it within velero until the upstream SDK is updated?

[anshulahuja98]

@schaafito can we consider using an older SDK version? Or do we need to the latest SDK with older API version.