Add e2e tests

[richardcase]

To give confidence that the providers work as expected we need to implement e2e tests.

[nasusoba]

Hi, to help improve the quality of capi-k3s and drive the production to be production-ready, I would love to init some work for e2e. I did some research and find that capi has released their e2e test-framework, so I am considering reusing it for our e2e test.

The plan is to use CAPD as the infrastructure provider, so that we could run the test easily (CAPI also used CAPD for e2e). The plan by steps:

1. Integrate with e2e test-framework
   • can run e2e test locally with make e2e-test
   • can run basic e2e test flow (i.e., creating a k3s cluster and verify it is provisioned). CAPI has a released test spec for this scenario, so we might also reuse it: QuickStartSpec
2. Add more test specs
   • I am not quite sure what other scenarios capi-k3s could support, need some support from the community. May try adding some scenarios that kubeadm controller supported.
3. More improvements
   • Integrate it as a PR blocker, so that broken change will not be merged to main
4. Maintainance work
   • like updating the test framework version

Please comment if there is already any work done for e2e, or any concerns and suggestions!

[mogliang]

assign to @nasusoba
Thanks for contributing on this project, Let's try to integrate with capi e2e test framework, and add first test.

@richardcase @zawachte please let me know if other guys are working on the same.

[zawachte]

sgtm