feat: Implement reconcile logic

[yiannistri]

Fixes: weaveworks/weave-gitops-enterprise#487

• Set condition when secret/CAPI cluster is found/not found
• Add watches for secrets/CAPI clusters to ensure reconcile function is being called when they get updated

[foot]

Code lgtm! Will try and do a quick run..

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Maybe we could add a couple of examples too

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Ah here is one config/samples/gitops_v1alpha1_cluster_capi.yaml !

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I don't see the status getting updated on the cluster objects 🤔 .

kubectl apply -f config/samples/gitops_v1alpha1_cluster_secret.yaml
make run

ewq:~/weave/cluster-controller(controller-crd *=)$ kubectl get clusters
NAME   READY   STATUS
dev
ewq:~/weave/cluster-controller(controller-crd *=)$ kubectl create secret generic dev --from-literal foo=bar
secret/dev created
ewq:~/weave/cluster-controller(controller-crd *=)$ kubectl get clusters
NAME   READY   STATUS
dev

Though the controller does show stuff going on the logs:

...

1.6481100800010188e+09  ERROR   controller.cluster      Reconciler error        {"reconciler group": "gitops.weave.works", "reconciler kind": "Cluster", "name": "dev", "namespace": "default", "e
rror": "failed to get secret \"default/dev\": Secret \"dev\" not found"}

...

1.6481101753450072e+09  INFO    controller.cluster      Secret found    {"reconciler group": "gitops.weave.works", "reconciler kind": "Cluster", "name": "dev", "namespace": "default", "secret": {"namespace": "default", "name": "dev"}}

[foot]

Awesome :)

[bigkevmcd]

You don't necessarily need to implement it in this branch but I don't think that the secret not being available isn't an error...it's somewhat expected.

Use https://pkg.go.dev/k8s.io/apimachinery/pkg/api/errors#IsNotFound and if the secret isn't found, I'd use a time-based RequeueAfter result.

If you return errors, you will get backoff, this will top out at 6m, but, as you can imagine, the longer you wait, the more likely it is that the secret will be available (because you're waiting for it to be created) so letting it backoff 'til the maximum means you'll wait for the longest period.