Ability to wait for CRD Resources to be ready

[rmb938]

Describe the solution you'd like to see

The ability to give a json path (or something similar) to wait for a certain value before the resource is considered ready.

Describe alternatives you've considered

Local exec to use kubectl and make a dependency chain somehow?

Additional context

Some CRDs have things in their status to determine if they are ready or not. So for example a cert-manager certificate.

apiVersion: certmanager.k8s.io/v1alpha1
kind: Certificate
metadata:
  name: my-cert
spec:
  dnsNames:
  - example.com
  issuerRef:
    kind: ClusterIssuer
    name: aws-pca
  secretName: cert-thanos
status:
  conditions:
  - lastTransitionTime: "2019-11-26T17:22:36Z"
    message: Certificate is up to date and has not expired
    reason: Ready
    status: "True"
    type: Ready
  notAfter: "2020-06-23T17:22:41Z"

Having some sort of way to select the Ready condition and waiting for it to be true.

Making something universal to work with any crd may be a bit difficult.

[mcristina422]

Some CRDs don't have simple status attributes that can be checked with a single JSONPath ( Like Conditions on Cert-manager Certificates ). A higher level language may be needed to parse the correct status. Argo (a k8s CI/CD tool) uses lua https://argoproj.github.io/argo-cd/operator-manual/health/

[bonifaido]

I'm really open to integrate something like this into the provider, I have faced the issue several times, and we have built-in "wait for status" for the most common standard resources only.

What about using https://github.com/google/cel-go instead of Lua, it is much more embeddable and we won't need a full-blown VM here in a terraform provider :)

[rmb938]

I never personally used CEL but it looks like it could work.

[mcristina422]

Hopefully the community can converge on some common status like kubernetes/enhancements#1624

[mh013370]

Why not mimic the behavior in the kubernetes provider?

https://registry.terraform.io/providers/hashicorp/kubernetes/latest/docs/resources/manifest#wait_for