lot of new functionalities

core/utils/storage/etcd.go

@@ -0,0 +1,164 @@
+package storage
+
+import (
+	"bytes"
+	"context"
+	"encoding/gob"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/viper"
+	clientv3 "go.etcd.io/etcd/client/v3"
+	"go.etcd.io/etcd/client/v3/namespace"
+)
+
+type EtcdSerializer interface {
+	Deserialize(d []byte, m *any) error
+	Serialize(m any) ([]byte, error)
+}
+
+type JSONEtcdSerializer struct{}
+
+// Serialize to JSON. Will err if there are unmarshalable key values
+func (s JSONEtcdSerializer) Serialize(m any) ([]byte, error) {
+	return json.Marshal(m)
+}
+
+// Deserialize back to map[string]interface{}
+func (s JSONEtcdSerializer) Deserialize(d []byte, m *any) (err error) {
+	err = json.Unmarshal(d, &m)
+	if err != nil {
+		fmt.Printf("JSONSerializer.deserialize() Error: %v", err)
+		return err
+	}
+	return
+}
+
+// GobEtcdSerializer uses gob package to encode the session map
+type GobEtcdSerializer struct{}
+
+// Serialize using gob
+func (s GobEtcdSerializer) Serialize(m any) ([]byte, error) {
+	buf := new(bytes.Buffer)
+	enc := gob.NewEncoder(buf)
+	err := enc.Encode(m)
+	if err == nil {
+		return buf.Bytes(), nil
+	}
+	return nil, err
+}
+
+// Deserialize back to map[interface{}]interface{}
+func (s GobEtcdSerializer) Deserialize(d []byte, m any) error {
+	dec := gob.NewDecoder(bytes.NewBuffer(d))
+	return dec.Decode(&m)
+}
+
+type EtcdHandler struct {
+	*clientv3.Client
+	serializer EtcdSerializer
+}
+
+func NewEtcdHandler(cfg *viper.Viper) (*EtcdHandler, error) {
+	var (
+		endpoints = cfg.GetStringSlice("storage.kv.etcd.endpoints")
+		prefix    = cfg.GetString("storage.kv.etcd.prefix")
+		username  = cfg.GetString("storage.kv.etcd.username")
+		password  = cfg.GetString("storage.kv.etcd.password")
+	)
+
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   endpoints,
+		Username:    username,
+		Password:    password,
+		DialTimeout: 5 * time.Second,
+	})
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return nil, err
+	}
+
+	cli.KV = namespace.NewKV(cli.KV, prefix)
+	cli.Watcher = namespace.NewWatcher(cli.Watcher, prefix)
+	cli.Lease = namespace.NewLease(cli.Lease, prefix)
+
+	return &EtcdHandler{
+		Client:     cli,
+		serializer: JSONEtcdSerializer{},
+	}, nil
+}
+
+func (s *EtcdHandler) Put(k string, v any) error {
+	data, err := s.serializer.Serialize(v)
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+	// _, err = s.Client.KV.Put(context.TODO(), k, data.String())
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	_, err = s.Client.KV.Put(ctx, k, string(data))
+	cancel()
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+	return nil
+}
+
+func (s *EtcdHandler) PutWithTTL(k string, v any, duration time.Duration) error {
+	lease, err := s.Client.Lease.Grant(context.TODO(), int64(duration.Seconds()))
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+
+	data, err := s.serializer.Serialize(v)
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+	// _, err = s.Client.KV.Put(context.TODO(), k, data.String(), clientv3.WithLease(lease.ID))
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	_, err = s.Client.KV.Put(ctx, k, string(data), clientv3.WithLease(lease.ID))
+	cancel()
+
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+	return nil
+}
+
+func (s *EtcdHandler) Get(k string) (any, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	resp, err := s.Client.KV.Get(ctx, k)
+	cancel()
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return nil, err
+	}
+	for _, v := range resp.Kvs {
+		var data any
+		err := s.serializer.Deserialize([]byte(v.Value), &data)
+		if err != nil {
+			log.Error().Err(err).Msg("")
+			return nil, err
+		}
+		// We return directly as we want to last revision of value
+		return data, nil
+	}
+	return nil, fmt.Errorf("no value %v", k)
+}
+
+func (s *EtcdHandler) Delete(k string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	_, err := s.Client.KV.Delete(ctx, k)
+	cancel()
+	if err != nil {
+		log.Error().Err(err).Msg("")
+		return err
+	}
+	return nil
+}