Azure: Retry getting network metadata during nic attach for all non-timeout errors

[aswinrajamannar]

Proposed Commit Message

Azure: Retry getting network metadata during nic attach for all non-timeout errors.

Summary

When network interfaces are hot-attached to the VM, attempting to get network metadata might return 410 (or 500, 503 etc) because the info is not yet available. In those cases, we retry getting the metadata before giving up. The only case where we can move on to wait for more nic attach events is if the call times out despite retries, which means the interface is not likely a primary interface, and we should try for more nic attach events.

Test Steps

• Deploy Pre-provisioned VM in Azure of type "savable" (internal to Azure)
• Reuse the VM with one or more network interfaces
• When repeating this multiple times, some of them might fail if the platform is not ready to serve the network metadata

Checklist:

• My code follows the process laid out in the documentation
• I have updated or added any unit tests accordingly
• I have updated or added any documentation accordingly

[TheRealFalcon]

Thanks!