There are two important components that a cluster would need to enable CRD versioning:

• Cert manager to manage certificates. API and conversion webhook communicate over TLS, hence the need for certs.
• Storage version migrator to migrate existing CRs to desired storage version defined in the CRD.

Following the quickstart from kubebuilder, scaffolded the files. (you don't need to do this if you're cloning the repo)

• kubebuilder create api --group webapp --version v1 --kind Guestbook

• In the v1 branch, "webapp.example.com/v1" API will be the stored version and "webapp.example.com/v2" will be introduced to users. Additionally, we could add a deprecation warning on "webapp.example.com/v1" and start requesting users to move to "webapp.example.com/v2".
• In the v2 branch, "webapp.example.com/v2" will be set as the stored version. Users can still view objects in "webapp.example.com/v1" but they should start migrating objects to "webapp.example.com/v2" using Storage Version Migrator.
• In the v3, "webapp.example.com/v1" will no longer be a served version, therefore deprecating it. Users can no longer view objects in v1.

• Run make install
• Run make deploy IMG=harshthakur/guestbook-controller