instance metadata issue fix

[vdhanan]

Is this a bug fix or adding new feature?
bug fix (fixes #474)

What is this PR about? / Why do we need it?
alternative way to fetch instance metadata

What testing is done?
manual and unit testing

messed up my original PR #846 this is a replacement for that one

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[k8s-ci-robot]

Hi @vdhanan. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[coveralls]

Pull Request Test Coverage Report for Build 1916

• 42 of 56 (75.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.06%) to 79.188%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/cloud/metadata.go	42	56	75.0%

Totals
Change from base Build 1911:	-0.06%
Covered Lines:	1990
Relevant Lines:	2513

---

💛 - Coveralls

[AndyXiangLi]

/ok-to-test

[wongma7]

IMO we should wrap this error in something helpful. like: error getting information from metadata service or node object : err. Looking back at the issue where people reported that the driver couldnt run because of metadata being unavailable, some context would have helped, because otherwise the driver just crashes with weird error.

[vdhanan]

can you confirm that this is the idiomatic way to wrap errors?

func NewMetadata() (MetadataService, error) {
	sess := session.Must(session.NewSession(&aws.Config{}))
	svc := ec2metadata.New(sess)
	// creates the in-cluster config
	config, err := rest.InClusterConfig()
	if err != nil && !svc.Available() {
		return nil, err
	}
	// creates the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil && !svc.Available() {
		return nil, err
	}
	metadataService, err := NewMetadataService(svc, clientset)
	if err != nil {
		err = fmt.Errorf("error getting information from metadata service or node object: %w", err)
	}
	return metadataService, err
}

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: vdhanan, wongma7

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• OWNERS [wongma7]

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[wongma7]

/lgtm

feel free to squash, i think im going to have to manually merge anyway if coveralls keeps complaining

[wongma7]

/lgtm

[wongma7]

/lgtm

[wongma7]

I'm going to merge, because coveralls is still complaining, and the lates tcommit was just changing helm chart and there's no need to retest.