Add package cluster :

- based on dragonboat lib (https://github.com/lni/dragonboat)
- add extended config with validate
- add backend managment to allow simple implementation for backend simple, cocurrent & disk
- has no backend implemented and must be a lib for a cluster mode of one backend

cluster/local.go

@@ -0,0 +1,53 @@
+/***********************************************************************************************************************
+ *
+ *   MIT License
+ *
+ *   Copyright (c) 2021 Nicolas JUHEL
+ *
+ *   Permission is hereby granted, free of charge, to any person obtaining a copy
+ *   of this software and associated documentation files (the "Software"), to deal
+ *   in the Software without restriction, including without limitation the rights
+ *   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *   copies of the Software, and to permit persons to whom the Software is
+ *   furnished to do so, subject to the following conditions:
+ *
+ *   The above copyright notice and this permission notice shall be included in all
+ *   copies or substantial portions of the Software.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *   SOFTWARE.
+ *
+ *
+ **********************************************************************************************************************/
+
+package cluster
+
+import (
+	dgbclt "github.com/lni/dragonboat/v3"
+	liberr "github.com/nabbar/golib/errors"
+)
+
+func (c *cRaft) LocalReadNode(rs *dgbclt.RequestState, query interface{}) (interface{}, liberr.Error) {
+	i, e := c.nodeHost.ReadLocalNode(rs, query)
+
+	if e != nil {
+		return i, ErrorCommandLocal.ErrorParent(c.getErrorCommand("ReadNode"), e)
+	}
+
+	return i, nil
+}
+
+func (c *cRaft) LocalNAReadNode(rs *dgbclt.RequestState, query []byte) ([]byte, liberr.Error) {
+	r, e := c.nodeHost.NAReadLocalNode(rs, query)
+
+	if e != nil {
+		return r, ErrorCommandLocal.ErrorParent(c.getErrorCommand("ReadNode"), e)
+	}
+
+	return r, nil
+}