[fix] : fix internal ip ordering

[rahulait]

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Node's internal ip is set based on whatever ip is returned as first internal ip. In case of VPC, we always want that ip to be node's internal ip. We do that ordering when returning node's ip-addresses. However, we were storing things in map and re-generating which was changing the order. Instead, we can just rely on map to tell if its unique or not and then append to the slice. This PR fixes that by making sure node's actual ip's are listed first and then the ones set by kubelet.

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[rahulait]

Adding ips first here as the ordering is already done in getInstanceAddresses() https://github.com/linode/linode-cloud-controller-manager/blob/main/cloud/linode/instances.go#L41-L63

[rosskirkpat]

thanks for clarifying this, I was about to leave a comment asking about that 😄

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 56.08%. Comparing base (9212805) to head (aaaf170).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
cloud/linode/instances.go	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #247      +/-   ##
==========================================
+ Coverage   56.06%   56.08%   +0.01%     
==========================================
  Files          12       12              
  Lines        2349     2350       +1     
==========================================
+ Hits         1317     1318       +1     
  Misses        881      881              
  Partials      151      151              

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[rosskirkpat]

overall, LGTM. Requested a new test to cover the specific scenario where this bug was observed

[rosskirkpat]

I noticed that there is no test covering the node scenario where we found this bug. Would you be able to add a test for it?

Here are the details:

Nodes have four IPs

• VPC Internal IP
• Private Internal IP
• ipv4 External IP
• ipv6 External IP

We need the VPC internal IP listed first in InternalIP and the ipv4 external IP listed first in ExternalIP

[rahulait]

Not sure about first externalIP as ipv4 only as we never did that before, but let me see if we can add such logic easily to the code. Maybe remove external ipv6's from slice and add it to the end of slice.

[dthorsen]

I believe the code is already doing that here:

linode-cloud-controller-manager/cloud/linode/instances.go

Lines 58 to 60 in 9212805

	if instance.IPv6 != "" {
	ips = append(ips, nodeIP{ip: strings.TrimSuffix(instance.IPv6, "/128"), ipType: v1.NodeExternalIP})
	}

[rahulait]

Yeah, true. Added test to make sure vpc ip is first and ipv6 at the end. external ipv4 and other internal ip's can be in any order.