PLT-6080 moving clustering to memberlist (#6499)

* PLT-6080 adding cluster discovery service

* Adding memberlist lib

* Adding memberlist lib

* WIP

* WIP

* WIP

* WIP

* Rolling back config changes

* Fixing make file

* Fixing config for cluster

* WIP

* Fixing system console for clustering

* Fixing default config

* Fixing config

* Fixing system console for clustering

* Tweaking hub setting

* Bumping up time

* merging vendor dir

* Updating vendor dir

* Fixing unit test

* Fixing bad merge

* Remove some testing code

* Moving comment

* PLT-6868 adding db ping retry

* Removing unused loc strings

* Adding defer to cancel

model/cluster_discovery_test.go

@@ -0,0 +1,59 @@
+// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestClusterDiscovery(t *testing.T) {
+	o := ClusterDiscovery{
+		Type:        "test_type",
+		ClusterName: "cluster_name",
+		Hostname:    "test_hostname",
+	}
+
+	json := o.ToJson()
+	result1 := ClusterDiscoveryFromJson(strings.NewReader(json))
+
+	if result1.ClusterName != "cluster_name" {
+		t.Fatal("should be set")
+	}
+
+	result2 := ClusterDiscoveryFromJson(strings.NewReader(json))
+	result3 := ClusterDiscoveryFromJson(strings.NewReader(json))
+
+	o.Id = "0"
+	result1.Id = "1"
+	result2.Id = "2"
+	result3.Id = "3"
+	result3.Hostname = "something_diff"
+
+	if !o.IsEqual(result1) {
+		t.Fatal("Should be equal")
+	}
+
+	list := make([]*ClusterDiscovery, 0)
+	list = append(list, &o)
+	list = append(list, result1)
+	list = append(list, result2)
+	list = append(list, result3)
+
+	rlist := FilterClusterDiscovery(list, func(in *ClusterDiscovery) bool {
+		return !o.IsEqual(in)
+	})
+
+	if len(rlist) != 1 {
+		t.Fatal("should only have 1 result")
+	}
+
+	o.AutoFillHostname()
+	o.Hostname = ""
+	o.AutoFillHostname()
+
+	o.AutoFillIpAddress()
+	o.Hostname = ""
+	o.AutoFillIpAddress()
+}