Don't register instance to LB target groups unless instance is running

[r4f4]

/kind bug

What steps did you take and what happened:

In the AWS docs, it's stated that registering an instance with LB target groups is only possible if the instance is running.

Currently CAPA just tries to register it anyway, resulting in the following error in the log output:

E0314 22:24:18.512176  701419 awsmachine_controller.go:605] "failed to reconcile LB attachment" err=<
    [could not register machine to load balancer: could not register control plane instance "i-039bb22b1e8df7c99" with load balancer: failed to register instance with target group 'mrb-capa-67-d2pfx-int-22623': InvalidTarget: The following targets are not in a running state and cannot be registered: 'i-039bb22b1e8df7c99'
        status code: 400, request id: 17514354-77ac-42b1-a882-489760563bbd, could not register machine to load balancer: could not register control plane instance "i-039bb22b1e8df7c99" with load balancer: failed to register instance with target group 'mrb-capa-67-d2pfx-ext-6443': InvalidTarget: The following targets are not in a running state and cannot be registered: 'i-039bb22b1e8df7c99'
        status code: 400, request id: 84e1849c-abb7-4af9-9220-8791fdc1a3fb]
 >
I0314 22:24:18.512325  701419 recorder.go:104] "events: Failed to register control plane instance \"i-039bb22b1e8df7c99\" with load balancer: failed to register instance with target group 'mrb-capa-67-d2pfx-ext-6443': InvalidTarget: The following targets are not in a running state and cannot be registered: 'i-039bb22b1e8df7c99'\n\tstatus code: 400, request id: 84e1849c-abb7-4af9-9220-8791fdc1a3fb" type="Warning" object={"kind":"AWSMachine","namespace":"openshift-cluster-api-guests","name":"mrb-capa-67-d2pfx-bootstrap","uid":"58af1162-380b-4f3e-93fe-c0e81401070e","apiVersion":"infrastructure.cluster.x-k8s.io/v1beta2","resourceVersion":"562"} reason="FailedAttachControlPlaneELB"

What did you expect to happen:

Even though this doesn't stop the install from succeeding, waiting for the instance to be running before registering it to target groups not only avoids the red herring error message but it also avoids unnecessary AWS API calls.

Anything else you would like to add:

Environment:

• Cluster-api-provider-aws version: master @ 1313226
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[k8s-ci-robot]

This issue is currently awaiting triage.

If CAPA/CAPI contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[r4f4]

/cc @mtulio