[node operator] node image util functions

Signed-off-by: Malte Poll <mp@edgeless.systems>

operators/constellation-node-operator/internal/node/node.go

@@ -1,15 +1,48 @@
 package node
 
-import corev1 "k8s.io/api/core/v1"
+import (
+	"regexp"
 
+	updatev1alpha1 "github.com/edgelesssys/constellation/operators/constellation-node-operator/api/v1alpha1"
+	corev1 "k8s.io/api/core/v1"
+)
+
+var reservedHostRegex = regexp.MustCompile(`^(.+\.|)(kubernetes|k8s)\.io(/.*)?$`)
+
+// Ready checks if a kubernetes node has the `NodeReady` condition set to true.
 func Ready(node *corev1.Node) bool {
 	for _, cond := range node.Status.Conditions {
 		if cond.Type == corev1.NodeReady {
-			if cond.Status == corev1.ConditionTrue {
-				return true
-			}
-			return false
+			return cond.Status == corev1.ConditionTrue
 		}
 	}
 	return false
 }
+
+// FindPending searches for a pending node that matches a node.
+// The pending node has to have the goal to join the cluster and be reported as ready be the CSP.
+// if the node is not found, nil is returned.
+func FindPending(pendingNodes []updatev1alpha1.PendingNode, node *corev1.Node) *updatev1alpha1.PendingNode {
+	if node == nil {
+		return nil
+	}
+	for _, pendingNode := range pendingNodes {
+		if pendingNode.Spec.Goal == updatev1alpha1.NodeGoalJoin && pendingNode.Spec.NodeName == node.Name && pendingNode.Status.CSPNodeState == updatev1alpha1.NodeStateReady {
+			return &pendingNode
+		}
+	}
+	return nil
+}
+
+// FilterLabels removes reserved node labels from a map of labels.
+// reference: https://kubernetes.io/docs/reference/labels-annotations-taints/ .
+func FilterLabels(labels map[string]string) map[string]string {
+	result := make(map[string]string)
+	for key, val := range labels {
+		if reservedHostRegex.MatchString(key) {
+			continue
+		}
+		result[key] = val
+	}
+	return result
+}