Change coredns testing to fix failing tests

[pascalgn]

Fixes #4240

[k8s-ci-robot]

Hi @pascalgn. Thanks for your PR.

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[mloiseleur]

/ok-to-test

[mloiseleur]

Suggested change

	err := coredns.ApplyChanges(context.Background(), changes1)
	if err != nil {
	t.Fatal(err)
	}
	err := coredns.ApplyChanges(context.Background(), changes1)
	require.NoError(t, err)

[pascalgn]

Fixed!

[mloiseleur]

Suggested change

	err = applyServiceChanges(coredns, changes2)
	if err != nil {
	t.Fatal(err)
	}
	err = applyServiceChanges(coredns, changes2)
	require.NoError(t, err)

[pascalgn]

Fixed!

[mloiseleur]

Suggested change

	if err != nil {
	t.Fatal(err)
	}
	require.NoError(t, err)

[pascalgn]

Fixed!

[mloiseleur]

@pascalgn Many thanks for this PR !

Wdyt about keeping :

1. services map[string]*Service ? You can see here another way to do it.
2. Use a more golang to check error in test case with require.NoError(...) ?

[szuecs]

You can also use strings.Clone to copy a string

[pascalgn]

Regarding services map[string]*Service, I thought about it like this:

someService.Host = "1.1.1.1"
client.SaveService(&someService)

someService.Host = "2.2.2.2"

Now, from what I understand, fakeETCDClient.services[0].Host == "2.2.2.2". But that should not happen, as then fakeETCDClient would be different from the real etcd implementation, because that one calls json.Marshal().

Therefore I thought it's not bad to change it to services map[string]Service, because then testing is a bit more similar to the real etcd. But I'm not sure, we can also keep it as *Service

[mloiseleur]

Ok, I understand.
/lgtm

[szuecs]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: szuecs

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