From cce7e30aebba1a9bc16856d830a19a5f8570d667 Mon Sep 17 00:00:00 2001
From: "Matthew R. Kasun" <mkasun@nusak.ca>
Date: Mon, 13 Jun 2022 15:19:25 -0400
Subject: [PATCH] only check for zombies on same network

---
 logic/nodes.go  |  3 +-
 logic/zombie.go | 96 +++++++++++++++++++++++++++++++++++++++++++++++++
 main.go         |  2 ++
 3 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 logic/zombie.go

diff --git a/logic/nodes.go b/logic/nodes.go
index 1377951a..218a7f23 100644
--- a/logic/nodes.go
+++ b/logic/nodes.go
@@ -213,7 +213,7 @@ func DeleteNodeByID(node *models.Node, exterminate bool) error {
 		// ignoring for now, could hit a nil pointer if delete called twice
 		logger.Log(2, "attempted to remove node ACL for node", node.Name, node.ID)
 	}
-
+	removeZombie <- node.ID
 	return removeLocalServer(node)
 }
 
@@ -313,6 +313,7 @@ func CreateNode(node *models.Node) error {
 	if err != nil {
 		return err
 	}
+	CheckZombies(node)
 
 	nodebytes, err := json.Marshal(&node)
 	if err != nil {
diff --git a/logic/zombie.go b/logic/zombie.go
new file mode 100644
index 00000000..badd7d1d
--- /dev/null
+++ b/logic/zombie.go
@@ -0,0 +1,96 @@
+package logic
+
+import (
+	"context"
+	"time"
+
+	"github.com/gravitl/netmaker/logger"
+	"github.com/gravitl/netmaker/models"
+)
+
+const (
+	ZOMBIE_TIMEOUT     = 60 // timeout in seconds
+	ZOMBIE_DELETE_TIME = 10 // minutes
+)
+
+var (
+	zombies      []string
+	removeZombie chan string = make(chan (string))
+	newZombie    chan string = make(chan (string))
+)
+
+// CheckZombies - checks if new node has same macaddress as existing node
+// if so, existing node is added to zombie node quarantine list
+func CheckZombies(newnode *models.Node) {
+	nodes, err := GetNetworkNodes(newnode.Network)
+	if err != nil {
+		logger.Log(1, "Failed to retrieve network nodes", newnode.Network, err.Error())
+		return
+	}
+	for _, node := range nodes {
+		if node.MacAddress == newnode.MacAddress {
+			newZombie <- node.ID
+		}
+	}
+}
+
+// ManageZombies - goroutine which adds/removes/deletes nodes from the zombie node quarantine list
+func ManageZombies(ctx context.Context) {
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case id := <-newZombie:
+			logger.Log(1, "adding", id, "to zombie quaratine list")
+			zombies = append(zombies, id)
+		case id := <-removeZombie:
+			for i, zombie := range zombies {
+				if zombie == id {
+					logger.Log(1, "removing zombie from quaratine list", zombie)
+					zombies = append(zombies[:i], zombies[i+1:]...)
+				}
+			}
+			logger.Log(3, "no zombies found")
+		case <-time.After(time.Second * ZOMBIE_TIMEOUT):
+			for i, zombie := range zombies {
+				node, err := GetNodeByID(zombie)
+				if err != nil {
+					logger.Log(1, "error retrieving zombie node", zombie, err.Error())
+					continue
+				}
+				if time.Since(time.Unix(node.LastCheckIn, 0)) > time.Minute*ZOMBIE_DELETE_TIME {
+					if err := DeleteNodeByID(&node, true); err != nil {
+						logger.Log(1, "error deleting zombie node", zombie, err.Error())
+					}
+					logger.Log(1, "deleting zombie node", node.Name)
+					zombies = append(zombies[:i], zombies[i+1:]...)
+				}
+			}
+		}
+	}
+}
+
+//InitializeZombies - populates the zombie quarantine list (should be called from initialization)
+func InitalizeZombies() {
+	nodes, err := GetAllNodes()
+	if err != nil {
+		logger.Log(1, "failed to retrieve nodes", err.Error())
+		return
+	}
+	for _, node := range nodes {
+		othernodes, err := GetNetworkNodes(node.Network)
+		if err != nil {
+			logger.Log(1, "failled to retrieve nodes for network", node.Network, err.Error())
+			continue
+		}
+		for _, othernode := range othernodes {
+			if node.MacAddress == othernode.MacAddress {
+				if node.LastCheckIn > othernode.LastCheckIn {
+					zombies = append(zombies, othernode.ID)
+				} else {
+					zombies = append(zombies, node.ID)
+				}
+			}
+		}
+	}
+}
diff --git a/main.go b/main.go
index 6eb7dc93..bb4a500b 100644
--- a/main.go
+++ b/main.go
@@ -127,6 +127,7 @@ func initialize() { // Client Mode Prereq Check
 			logger.Log(0, "error occurred when notifying nodes of startup", err.Error())
 		}
 	}
+	logic.InitalizeZombies()
 }
 
 func startControllers() {
@@ -169,6 +170,7 @@ func runMessageQueue(wg *sync.WaitGroup) {
 	var client = mq.SetupMQTT(false) // Set up the subscription listener
 	ctx, cancel := context.WithCancel(context.Background())
 	go mq.Keepalive(ctx)
+	go logic.ManageZombies(ctx)
 	quit := make(chan os.Signal, 1)
 	signal.Notify(quit, syscall.SIGTERM, os.Interrupt)
 	<-quit