This commit implements a reconciler for the new `ProxyGroupPolicy`
custom resource. When created, all `ProxyGroupPolicy` resources
within the same namespace are merged into two `ValidatingAdmissionPolicy`
resources, one for egress and one for ingress.
These policies use CEL expressions to limit the usage of the
"tailscale.com/proxy-group" annotation on `Service` and `Ingress`
resources on create & update.
Included here is also a new e2e test that ensures that resources that
violate the policy return an error on creation, and that once the
policy is changed to allow them they can be created.
Closes: https://github.com/tailscale/corp/issues/36830
Signed-off-by: David Bond <davidsbond93@gmail.com>
This commit adds a new custom resource definition to the kubernetes
operator named `ProxyGroupPolicy`. This resource is namespace scoped
and is used as an allow list for which `ProxyGroup` resources can be
used within its namespace.
The `spec` contains two fields, `ingress` and `egress`. These should
contain the names of `ProxyGroup` resources to denote which can be
used as values in the `tailscale.com/proxy-group` annotation within
`Service` and `Ingress` resources.
The intention is for these policies to be merged within a namespace and
produce a `ValidatingAdmissionPolicy` and `ValidatingAdmissionPolicyBinding`
for both ingress and egress that prevents users from using names of
`ProxyGroup` resources in those annotations.
Closes: https://github.com/tailscale/corp/issues/36829
Signed-off-by: David Bond <davidsbond93@gmail.com>
David Bond