Add vxlanEnabled spec in FelixConfiguration

[devinjeon]

What type of PR is this?
/kind bug

What this PR does / why we need it:
Adding vxlanEnabled spec to FelixConfiguration CRD.

When using vxlan mode in Calico CNI, the entire Calico network stops working if we upgrade the cluster with the playbook upgrade-cluster.yml.

This is because vxlanEnabled disappeared in FelixConfiguration CRD spec. The related network settings(network interfaces, routing tables, etc.) are removed together and then the whole Pod network stops working.

More details(Why the spec vxlanEnabled is removed in FelixConfiguration CRD)

Currently, the spec vxlanEnabled: true is not configured in the task defining FelixConfiguration CRD

The reason VXLAN mode works well at the initial installation is that the spec vxlanEnabled: true is automatically(or dynamically) added to FelixConfiguration CRD when running the task configuring Calico network pool. It seems like the behavior of libcalico

However, the task for Calico network pool is not triggered if the IPPool is already exists(i.e. when upgrading cluster).

I added vxlanEnabled: true to the FelixConfiguration spec template in the task defining FelixConfiguration CRD so that it does not disappear even when the cluster is upgraded.

Reproduce:

Set up a new Kubernetes cluster with the following variables to set VXLAN mode in Calico:

calico_network_backend: vxlan
calico_ipip_mode: Never
calico_vxlan_mode: Always

After initial installation, we can see "vxlanEnabled: true" in the felixConfiguration object.

$ kubectl get felixConfiguration default -o yaml
...
spec:
  ...
  ipipEnabled: false
  vxlanEnabled: true  # this spec is removed after running `upgrade-cluster.yml`
  ...

Which issue(s) this PR fixes:

Special notes for your reviewer:

NONE

Does this PR introduce a user-facing change?:

[Calico] Add vxlanEnabled spec in FelixConfiguration to prevent calico network (when using vxlan) from crashing after upgrading the cluster

[k8s-ci-robot]

Welcome @devinjeon!

It looks like this is your first PR to kubernetes-sigs/kubespray 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/kubespray has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @devinjeon. 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[cristicalin]

Thank you for spotting this @devinjeon !

/ok-to-test
/lgtm

[floryut]

@devinjeon Wow, detail explanation is always a good thing, thanks for that and the fix

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: devinjeon, floryut

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [floryut]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment