From 810c08e6542aa58fe52ba187d99be5bb5a7eb3ce Mon Sep 17 00:00:00 2001
From: Roberto Bonafiglia <roberto.bonafiglia@suse.com>
Date: Wed, 31 Jul 2024 17:59:21 +0200
Subject: [PATCH] Fixed hns clean only in case of reboot

Signed-off-by: Roberto Bonafiglia <roberto.bonafiglia@suse.com>
---
 pkg/windows/calico.go | 51 +++++++++++++++++++++++++++++++++++++++++--
 pkg/windows/utils.go  |  6 +++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/pkg/windows/calico.go b/pkg/windows/calico.go
index 4892320fef..40a74c8711 100644
--- a/pkg/windows/calico.go
+++ b/pkg/windows/calico.go
@@ -21,6 +21,7 @@ import (
 	"github.com/rancher/rke2/pkg/logging"
 	"github.com/sirupsen/logrus"
 	opv1 "github.com/tigera/operator/api/v1"
+	"golang.org/x/sys/windows"
 	authv1 "k8s.io/api/authentication/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -302,8 +303,14 @@ func (c *Calico) Start(ctx context.Context) error {
 
 // generateCalicoNetworks creates the overlay networks for internode networking
 func (c *Calico) generateCalicoNetworks() error {
-	if err := deleteAllNetworks(); err != nil {
-		return errors.Wrapf(err, "failed to delete all networks before bootstrapping calico")
+	nodeRebooted, err := c.isNodeRebooted()
+	if err != nil {
+		return errors.Wrapf(err, "failed to check last node reboot time")
+	}
+	if nodeRebooted {
+		if err = deleteAllNetworks(); err != nil {
+			return errors.Wrapf(err, "failed to delete all networks before bootstrapping calico")
+		}
 	}
 
 	// There are four ways to select the vxlan interface. In order of priority:
@@ -528,3 +535,43 @@ func (c *Calico) ReserveSourceVip(ctx context.Context) (string, error) {
 
 	return vip, nil
 }
+
+//Get latest stored reboot
+func (c *Calico) getStoredLastBootTime() (string, error) {
+	lastRebootPath := filepath.Join(c.CNICfg.ConfigPath, "lastBootTime.txt")
+	lastStoredBoot, err := os.ReadFile(lastRebootPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return "", nil
+		} else {
+			return "", err
+		}
+	}
+	return string(lastStoredBoot), nil
+}
+
+//Set last boot time on the registry
+func (c *Calico) setStoredLastBootTime(lastBootTime string) error {
+	lastRebootPath := filepath.Join(c.CNICfg.ConfigPath, "lastBootTime.txt")
+	err := os.WriteFile(lastRebootPath, []byte(lastBootTime), 0644)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Check if the node was rebooted
+func (c *Calico) isNodeRebooted() (bool, error) {
+	tickCountSinceBoot := windows.DurationSinceBoot()
+	bootTime := time.Now().Add(-tickCountSinceBoot)
+	lastReboot := bootTime.Format(time.UnixDate)
+	prevLastReboot, err := c.getStoredLastBootTime()
+	if err != nil {
+		return true, err
+	}
+	if lastReboot == prevLastReboot {
+		return false, nil
+	}
+	err = c.setStoredLastBootTime(lastReboot)
+	return true, err
+}
diff --git a/pkg/windows/utils.go b/pkg/windows/utils.go
index 772de9f3f1..7721d9c302 100644
--- a/pkg/windows/utils.go
+++ b/pkg/windows/utils.go
@@ -34,6 +34,12 @@ var (
 // createHnsNetwork creates the network that will connect nodes and returns its managementIP
 func createHnsNetwork(backend string, networkAdapter string) (string, error) {
 	var network hcsshim.HNSNetwork
+        // Check if the interface already exists
+	hcsnetwork, err := hcsshim.GetHNSNetworkByName(CalicoHnsNetworkName)
+	if err == nil {
+		return hcsnetwork.ManagementIP, nil
+	}
+
 	if backend == "vxlan" {
 		// Ignoring the return because both true and false without an error represent that the firewall rule was created or already exists
 		if _, err := wapi.FirewallRuleAdd("OverlayTraffic4789UDP", "Overlay network traffic UDP", "", "4789", wapi.NET_FW_IP_PROTOCOL_UDP, wapi.NET_FW_PROFILE2_ALL); err != nil {