clustermesh: Add helper functions to set/get cluster configuration

Add hepler functions to set/get cluster information on kvstore.

Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com>

pkg/clustermesh/clustermesh.go

@@ -5,13 +5,16 @@ package clustermesh
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"path"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 
 	"github.com/cilium/cilium/api/v1/models"
 	"github.com/cilium/cilium/pkg/allocator"
+	cmtypes "github.com/cilium/cilium/pkg/clustermesh/types"
 	"github.com/cilium/cilium/pkg/controller"
 	"github.com/cilium/cilium/pkg/ipcache"
 	"github.com/cilium/cilium/pkg/kvstore"
@@ -73,6 +76,43 @@ type Configuration struct {
 	NodesSharedKeyDeleteDelay *time.Duration
 }
 
+func SetClusterConfig(clusterName string, config *cmtypes.CiliumClusterConfig, backend kvstore.BackendOperations) error {
+	key := path.Join(kvstore.ClusterConfigPrefix, clusterName)
+
+	val, err := json.Marshal(config)
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	_, err = kvstore.Client().UpdateIfDifferent(ctx, key, val, true)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func GetClusterConfig(clusterName string, backend kvstore.BackendOperations) (*cmtypes.CiliumClusterConfig, error) {
+	var config cmtypes.CiliumClusterConfig
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+
+	val, err := backend.Get(ctx, path.Join(kvstore.ClusterConfigPrefix, clusterName))
+	if err != nil {
+		return nil, err
+	}
+
+	if err := json.Unmarshal(val, &config); err != nil {
+		return nil, err
+	}
+
+	return &config, nil
+}
+
 // RemoteIdentityWatcher is any type which provides identities that have been
 // allocated on a remote cluster.
 type RemoteIdentityWatcher interface {