Feature/name k8s node

[adilyse]

Update of PR #103.

Changes proposed in this PR:

• Be able to configure the synthetic Consul node name where catalog sync registers services.

How I've tested this PR:
Using consul-helm #580, I deployed with catalog sync enabled by default.

How I expect reviewers to test this PR:
Similarly.

Checklist:
☑️ Tests added
☑️ CHANGELOG entry added (HashiCorp engineers only, community PRs should not add a changelog entry)
-> to be added when the PR exists to link to

[thisisnotashwin]

This looks great!! Had a few suggested changes, but LGTM with those addressed

[thisisnotashwin]

Re-approving for posterity 😉

[ishustava]

This mostly looks good and works in a non-secure installation; thanks for making these changes!

The one major issue I've found is that it doesn't work with ACLs enabled. That is because the ACL rules for the sync catalog process hard-code the node name to k8s-sync. Once that is fixed, we will also need to make sure that the token is updated when the node name changes. Currently, the behavior of the acl-init job is to not update the token if the Kubernetes secret for a component already exists.

Other than that, I had a question about adding ConsulNodeName to the Syncer interface. I don't think this is the pattern we've used here in the past, so I'm curious why you decided to implement it this way.

[adilyse]

Good catch on the ACLs! I've added support in the ACL system for configuring and updating the sync node name.

[ishustava]

The ACL changes look good! Everything works as expected from a functional perspective with ACLs enabled. Thank you for adding those validations checking that node names are valid DNS names too!

I have a couple of comments about the code. I'd like to address them before we merge if possible:

1. About the Syncer interface, I'd prefer that we used our existing pattern of passing the node name directly to the resource struct rather than changing the Syncer interface.
2. We don't have any tests in resource_test.go or syncer_test.go that check that changing the node name works. I left some comments about that in my first review.

I've also left a couple of suggestions.