feat: Add etcd database support

improve concurrent access and high availability of aptly with the help of the characteristics of etcd

database/etcddb/database.go

@@ -0,0 +1,45 @@
+package etcddb
+
+import (
+	"context"
+	"time"
+
+	"github.com/aptly-dev/aptly/database"
+	clientv3 "go.etcd.io/etcd/client/v3"
+)
+
+var Ctx = context.TODO()
+
+func internalOpen(url string) (*clientv3.Client, error) {
+	cfg := clientv3.Config{
+		Endpoints:            []string{url},
+		DialTimeout:          30 * time.Second,
+		MaxCallSendMsgSize:   2048 * 1024 * 1024,
+		MaxCallRecvMsgSize:   2048 * 1024 * 1024,
+		DialKeepAliveTimeout: 7200 * time.Second,
+	}
+
+	cli, err := clientv3.New(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return cli, nil
+}
+
+func NewDB(url string) (database.Storage, error) {
+	cli, err := internalOpen(url)
+	if err != nil {
+		return nil, err
+	}
+	return &EtcDStorage{url, cli}, nil
+}
+
+func NewOpenDB(url string) (database.Storage, error) {
+	db, err := NewDB(url)
+	if err != nil {
+		return nil, err
+	}
+
+	return db, nil
+}