cli: add kubernetes pkg to interface with cluster

Previously the content of files status and upgrade within the
cloudcmd pkg did not fit cloudcmd's pkg description.
This patch introduces a separate pkg to fix that.

cli/internal/kubernetes/status.go

@@ -0,0 +1,92 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package kubernetes
+
+import (
+	"context"
+	"fmt"
+
+	updatev1alpha1 "github.com/edgelesssys/constellation/v2/operators/constellation-node-operator/v2/api/v1alpha1"
+	corev1 "k8s.io/api/core/v1"
+)
+
+// TargetVersions bundles version information about the target versions of a cluster.
+type TargetVersions struct {
+	// image version
+	image string
+	// CSP specific path to the image
+	imageReference string
+	// kubernetes version
+	kubernetes string
+}
+
+// NewTargetVersions returns the target versions for the cluster.
+func NewTargetVersions(nodeVersion updatev1alpha1.NodeVersion) (TargetVersions, error) {
+	return TargetVersions{
+		image:          nodeVersion.Spec.ImageVersion,
+		imageReference: nodeVersion.Spec.ImageReference,
+		kubernetes:     nodeVersion.Spec.KubernetesClusterVersion,
+	}, nil
+}
+
+// Image return the image version.
+func (c *TargetVersions) Image() string {
+	return c.image
+}
+
+// ImagePath return the image path.
+func (c *TargetVersions) ImagePath() string {
+	return c.imageReference
+}
+
+// Kubernetes return the Kubernetes version.
+func (c *TargetVersions) Kubernetes() string {
+	return c.kubernetes
+}
+
+// ClusterStatus returns a map from node name to NodeStatus.
+func ClusterStatus(ctx context.Context, kubeclient kubeClient) (map[string]NodeStatus, error) {
+	nodes, err := kubeclient.GetNodes(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("getting nodes: %w", err)
+	}
+
+	clusterStatus := map[string]NodeStatus{}
+	for _, node := range nodes {
+		clusterStatus[node.ObjectMeta.Name] = NewNodeStatus(node)
+	}
+
+	return clusterStatus, nil
+}
+
+// NodeStatus bundles status information about a node.
+type NodeStatus struct {
+	kubeletVersion string
+	imageVersion   string
+}
+
+// NewNodeStatus returns a new NodeStatus.
+func NewNodeStatus(node corev1.Node) NodeStatus {
+	return NodeStatus{
+		kubeletVersion: node.Status.NodeInfo.KubeletVersion,
+		imageVersion:   node.ObjectMeta.Annotations["constellation.edgeless.systems/node-image"],
+	}
+}
+
+// KubeletVersion returns the kubelet version of the node.
+func (n *NodeStatus) KubeletVersion() string {
+	return n.kubeletVersion
+}
+
+// ImageVersion returns the node image of the node.
+func (n *NodeStatus) ImageVersion() string {
+	return n.imageVersion
+}
+
+type kubeClient interface {
+	GetNodes(ctx context.Context) ([]corev1.Node, error)
+}