func CheckTargetsReady()

in clusterloader2/pkg/prometheus/util.go [61:106]
45 lines of code
10 McCabe index (conditional complexity)

func CheckTargetsReady(k8sClient kubernetes.Interface, selector func(Target) bool, minActiveTargets, minReadyTargets int) (bool, error) {
	raw, err := k8sClient.CoreV1().
		Services(namespace).
		ProxyGet("http", "prometheus-k8s", "9090", "api/v1/targets", nil /*params*/).
		DoRaw(context.TODO())
	if err != nil {
		response := "(empty)"
		if raw != nil {
			response = string(raw)
		}
		// This might happen if prometheus server is temporary down, log error but don't return it.
		klog.Warningf("error while calling prometheus api: %v, response: %v", err, response)
		return false, nil
	}
	var response targetsResponse
	if err := json.Unmarshal(raw, &response); err != nil {
		return false, err // This shouldn't happen, return error.
	}
	nReady, nTotal := 0, 0
	var exampleNotReadyTarget Target
	for _, t := range response.Data.ActiveTargets {
		if !selector(t) {
			continue
		}
		nTotal++
		if t.Health == "up" {
			nReady++
			continue
		}
		exampleNotReadyTarget = t
	}
	if nTotal < minActiveTargets {
		klog.V(2).Infof("Not enough active targets (%d), expected at least (%d), waiting for more to become active...",
			nTotal, minActiveTargets)
		return false, nil
	}
	if minReadyTargets == allTargets {
		minReadyTargets = nTotal
	}
	if nReady < minReadyTargets {
		klog.V(2).Infof("%d/%d targets are ready, example not ready target: %v", nReady, minReadyTargets, exampleNotReadyTarget)
		return false, nil
	}
	klog.V(2).Infof("All %d expected targets are ready", minReadyTargets)
	return true, nil
}