joinservice: use configmap for k8s components

joinservice/internal/kubernetes/kubernetes.go

@@ -0,0 +1,85 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package kubernetes
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/edgelesssys/constellation/v2/internal/constants"
+	"github.com/edgelesssys/constellation/v2/internal/versions"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+)
+
+// Client is a kubernetes client.
+type Client struct {
+	client *kubernetes.Clientset
+}
+
+// New creates a new kubernetes client.
+func New() (*Client, error) {
+	// creates the in-cluster config
+	config, err := rest.InClusterConfig()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create in-cluster config: %w", err)
+	}
+	// creates the clientset
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create clientset: %w", err)
+	}
+	return &Client{client: clientset}, nil
+}
+
+// GetComponents returns the components of the cluster.
+func (c *Client) GetComponents(ctx context.Context, configMapName string) (versions.ComponentVersions, error) {
+	componentsRaw, err := c.getConfigMapData(ctx, configMapName, constants.ComponentsListKey)
+	if err != nil {
+		return versions.ComponentVersions{}, fmt.Errorf("failed to get components: %w", err)
+	}
+	var components versions.ComponentVersions
+	if err := json.Unmarshal([]byte(componentsRaw), &components); err != nil {
+		return versions.ComponentVersions{}, fmt.Errorf("failed to unmarshal components %s: %w", componentsRaw, err)
+	}
+	return components, nil
+}
+
+func (c *Client) getConfigMapData(ctx context.Context, name, key string) (string, error) {
+	cm, err := c.client.CoreV1().ConfigMaps("kube-system").Get(ctx, name, metav1.GetOptions{})
+	if err != nil {
+		return "", fmt.Errorf("failed to get configmap: %w", err)
+	}
+
+	return cm.Data[key], nil
+}
+
+// CreateConfigMap creates the provided configmap.
+func (c *Client) CreateConfigMap(ctx context.Context, configMap corev1.ConfigMap) error {
+	_, err := c.client.CoreV1().ConfigMaps(configMap.ObjectMeta.Namespace).Create(ctx, &configMap, metav1.CreateOptions{})
+	if err != nil {
+		return fmt.Errorf("failed to create configmap: %w", err)
+	}
+	return nil
+}
+
+// AddReferenceToK8sVersionConfigMap adds a reference to the provided configmap to the k8s version configmap.
+func (c *Client) AddReferenceToK8sVersionConfigMap(ctx context.Context, k8sVersionsConfigMapName string, componentsConfigMapName string) error {
+	cm, err := c.client.CoreV1().ConfigMaps("kube-system").Get(ctx, k8sVersionsConfigMapName, metav1.GetOptions{})
+	if err != nil {
+		return fmt.Errorf("failed to get configmap: %w", err)
+	}
+	cm.Data[constants.K8sComponentsFieldName] = componentsConfigMapName
+	_, err = c.client.CoreV1().ConfigMaps("kube-system").Update(ctx, cm, metav1.UpdateOptions{})
+	if err != nil {
+		return fmt.Errorf("failed to update configmap: %w", err)
+	}
+	return nil
+}