From cbf9ed3308cee6042359615a38417a45459e15e6 Mon Sep 17 00:00:00 2001
From: Manuel Buil <mbuil@suse.com>
Date: Wed, 9 Nov 2022 18:05:10 +0100
Subject: [PATCH] Use nodeIP to decide the overlay network NIC in windows

Signed-off-by: Manuel Buil <mbuil@suse.com>
---
 pkg/windows/calico.go         | 37 +++++++++++++++++++++++++++++++++--
 tests/e2e/mixedos/Vagrantfile |  2 ++
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/pkg/windows/calico.go b/pkg/windows/calico.go
index 4cd1822817..6ec2636781 100644
--- a/pkg/windows/calico.go
+++ b/pkg/windows/calico.go
@@ -277,12 +277,23 @@ func (c *Calico) Start(ctx context.Context) error {
 	return nil
 }
 
+// generateCalicoNetworks creates the overlay networks for internode networking
 func (c *Calico) generateCalicoNetworks() error {
 	if err := deleteAllNetworksOnNodeRestart(); err != nil {
 		return err
 	}
 
-	mgmt, err := createHnsNetwork(c.CNICfg.Mode, os.Getenv("VXLAN_ADAPTER"))
+	vxlanAdapter := os.Getenv("VXLAN_ADAPTER")
+
+	if vxlanAdapter == "" && c.CNICfg.IP != "" {
+		iFace, err := findInterface(c.CNICfg.IP)
+		if err != nil {
+			return err
+		}
+		vxlanAdapter = iFace
+	}
+
+	mgmt, err := createHnsNetwork(c.CNICfg.Mode, vxlanAdapter)
 	if err != nil {
 		return err
 	}
@@ -293,7 +304,6 @@ func (c *Calico) generateCalicoNetworks() error {
 			return err
 		}
 	}
-
 	return nil
 }
 
@@ -606,3 +616,26 @@ func generateGeneralCalicoEnvs(config *CalicoConfig) []string {
 		fmt.Sprintf("VXLAN_VNI=%s", config.Felix.Vxlanvni),
 	}
 }
+
+// findInterface returns the name of the interface that contains the passed ip
+func findInterface(ip string) (string, error) {
+	iFaces, err := net.Interfaces()
+	if err != nil {
+		return "", err
+	}
+
+	for _, iFace := range iFaces {
+		addrs, err := iFace.Addrs()
+		if err != nil {
+			return "", err
+		}
+		logrus.Debugf("evaluating if the interface: %s with addresses %v, contains ip: %s", iFace.Name, addrs, ip)
+		for _, addr := range addrs {
+			if strings.Contains(addr.String(), ip) {
+				return iFace.Name, nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("no interface has the ip: %s", ip)
+}
diff --git a/tests/e2e/mixedos/Vagrantfile b/tests/e2e/mixedos/Vagrantfile
index 9970cf5912..0336988f14 100644
--- a/tests/e2e/mixedos/Vagrantfile
+++ b/tests/e2e/mixedos/Vagrantfile
@@ -77,6 +77,7 @@ def provision(vm, role, role_num, node_num)
       rke2.config = <<~YAML
         write-kubeconfig-mode: '0644'
         node-external-ip: #{node_ip}
+        node-ip: #{node_ip}
         server: https://#{NETWORK_PREFIX}.100:9345
         token: vagrant-rke2
       YAML
@@ -103,6 +104,7 @@ def provision(vm, role, role_num, node_num)
       # rke2.skip_start = true
       rke2.config = <<~YAML
         node-external-ip: #{node_ip}
+        node-ip: #{node_ip}
         server: https://#{NETWORK_PREFIX}.100:9345
         token: vagrant-rke2
       YAML