Kubelet: only sync iptables on linux

pkg/kubelet/BUILD

@@ -14,6 +14,8 @@ go_library(
         "kubelet.go",
         "kubelet_getters.go",
         "kubelet_network.go",
+        "kubelet_network_linux.go",
+        "kubelet_network_others.go",
         "kubelet_node_status.go",
         "kubelet_pods.go",
         "kubelet_resources.go",

pkg/kubelet/kubelet_network.go

@@ -77,91 +77,6 @@ func (kl *Kubelet) updatePodCIDR(cidr string) error {
 	return nil
 }
 
-// syncNetworkUtil ensures the network utility are present on host.
-// Network util includes:
-// 1. 	In nat table, KUBE-MARK-DROP rule to mark connections for dropping
-// 	Marked connection will be drop on INPUT/OUTPUT Chain in filter table
-// 2. 	In nat table, KUBE-MARK-MASQ rule to mark connections for SNAT
-// 	Marked connection will get SNAT on POSTROUTING Chain in nat table
-func (kl *Kubelet) syncNetworkUtil() {
-	if kl.iptablesMasqueradeBit < 0 || kl.iptablesMasqueradeBit > 31 {
-		glog.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", kl.iptablesMasqueradeBit)
-		return
-	}
-
-	if kl.iptablesDropBit < 0 || kl.iptablesDropBit > 31 {
-		glog.Errorf("invalid iptables-drop-bit %v not in [0, 31]", kl.iptablesDropBit)
-		return
-	}
-
-	if kl.iptablesDropBit == kl.iptablesMasqueradeBit {
-		glog.Errorf("iptables-masquerade-bit %v and iptables-drop-bit %v must be different", kl.iptablesMasqueradeBit, kl.iptablesDropBit)
-		return
-	}
-
-	// Setup KUBE-MARK-DROP rules
-	dropMark := getIPTablesMark(kl.iptablesDropBit)
-	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkDropChain); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkDropChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkDropChain, "-j", "MARK", "--set-xmark", dropMark); err != nil {
-		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkDropChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureChain(utiliptables.TableFilter, KubeFirewallChain); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableFilter, KubeFirewallChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableFilter, KubeFirewallChain,
-		"-m", "comment", "--comment", "kubernetes firewall for dropping marked packets",
-		"-m", "mark", "--mark", dropMark,
-		"-j", "DROP"); err != nil {
-		glog.Errorf("Failed to ensure rule to drop packet marked by %v in %v chain %v: %v", KubeMarkDropChain, utiliptables.TableFilter, KubeFirewallChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainOutput, "-j", string(KubeFirewallChain)); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainOutput, KubeFirewallChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainInput, "-j", string(KubeFirewallChain)); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainInput, KubeFirewallChain, err)
-		return
-	}
-
-	// Setup KUBE-MARK-MASQ rules
-	masqueradeMark := getIPTablesMark(kl.iptablesMasqueradeBit)
-	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkMasqChain); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkMasqChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubePostroutingChain); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubePostroutingChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkMasqChain, "-j", "MARK", "--set-xmark", masqueradeMark); err != nil {
-		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkMasqChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting,
-		"-m", "comment", "--comment", "kubernetes postrouting rules", "-j", string(KubePostroutingChain)); err != nil {
-		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, KubePostroutingChain, err)
-		return
-	}
-	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubePostroutingChain,
-		"-m", "comment", "--comment", "kubernetes service traffic requiring SNAT",
-		"-m", "mark", "--mark", masqueradeMark, "-j", "MASQUERADE"); err != nil {
-		glog.Errorf("Failed to ensure SNAT rule for packets marked by %v in %v chain %v: %v", KubeMarkMasqChain, utiliptables.TableNAT, KubePostroutingChain, err)
-		return
-	}
-}
-
-// getIPTablesMark returns the fwmark given the bit
-func getIPTablesMark(bit int) string {
-	value := 1 << uint(bit)
-	return fmt.Sprintf("%#08x/%#08x", value, value)
-}
-
 // GetPodDNS returns DNS settings for the pod.
 // This function is defined in kubecontainer.RuntimeHelper interface so we
 // have to implement it.

pkg/kubelet/kubelet_network_linux.go

@@ -0,0 +1,111 @@
+// +build linux
+
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubelet
+
+import (
+	"fmt"
+
+	"github.com/golang/glog"
+	utiliptables "k8s.io/kubernetes/pkg/util/iptables"
+)
+
+// syncNetworkUtil ensures the network utility are present on host.
+// Network util includes:
+// 1. 	In nat table, KUBE-MARK-DROP rule to mark connections for dropping
+// 	Marked connection will be drop on INPUT/OUTPUT Chain in filter table
+// 2. 	In nat table, KUBE-MARK-MASQ rule to mark connections for SNAT
+// 	Marked connection will get SNAT on POSTROUTING Chain in nat table
+func (kl *Kubelet) syncNetworkUtil() {
+	if kl.iptablesMasqueradeBit < 0 || kl.iptablesMasqueradeBit > 31 {
+		glog.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", kl.iptablesMasqueradeBit)
+		return
+	}
+
+	if kl.iptablesDropBit < 0 || kl.iptablesDropBit > 31 {
+		glog.Errorf("invalid iptables-drop-bit %v not in [0, 31]", kl.iptablesDropBit)
+		return
+	}
+
+	if kl.iptablesDropBit == kl.iptablesMasqueradeBit {
+		glog.Errorf("iptables-masquerade-bit %v and iptables-drop-bit %v must be different", kl.iptablesMasqueradeBit, kl.iptablesDropBit)
+		return
+	}
+
+	// Setup KUBE-MARK-DROP rules
+	dropMark := getIPTablesMark(kl.iptablesDropBit)
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkDropChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkDropChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkDropChain, "-j", "MARK", "--set-xmark", dropMark); err != nil {
+		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkDropChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableFilter, KubeFirewallChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableFilter, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableFilter, KubeFirewallChain,
+		"-m", "comment", "--comment", "kubernetes firewall for dropping marked packets",
+		"-m", "mark", "--mark", dropMark,
+		"-j", "DROP"); err != nil {
+		glog.Errorf("Failed to ensure rule to drop packet marked by %v in %v chain %v: %v", KubeMarkDropChain, utiliptables.TableFilter, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainOutput, "-j", string(KubeFirewallChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainOutput, KubeFirewallChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableFilter, utiliptables.ChainInput, "-j", string(KubeFirewallChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableFilter, utiliptables.ChainInput, KubeFirewallChain, err)
+		return
+	}
+
+	// Setup KUBE-MARK-MASQ rules
+	masqueradeMark := getIPTablesMark(kl.iptablesMasqueradeBit)
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubeMarkMasqChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubeMarkMasqChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureChain(utiliptables.TableNAT, KubePostroutingChain); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s exists: %v", utiliptables.TableNAT, KubePostroutingChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubeMarkMasqChain, "-j", "MARK", "--set-xmark", masqueradeMark); err != nil {
+		glog.Errorf("Failed to ensure marking rule for %v: %v", KubeMarkMasqChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Prepend, utiliptables.TableNAT, utiliptables.ChainPostrouting,
+		"-m", "comment", "--comment", "kubernetes postrouting rules", "-j", string(KubePostroutingChain)); err != nil {
+		glog.Errorf("Failed to ensure that %s chain %s jumps to %s: %v", utiliptables.TableNAT, utiliptables.ChainPostrouting, KubePostroutingChain, err)
+		return
+	}
+	if _, err := kl.iptClient.EnsureRule(utiliptables.Append, utiliptables.TableNAT, KubePostroutingChain,
+		"-m", "comment", "--comment", "kubernetes service traffic requiring SNAT",
+		"-m", "mark", "--mark", masqueradeMark, "-j", "MASQUERADE"); err != nil {
+		glog.Errorf("Failed to ensure SNAT rule for packets marked by %v in %v chain %v: %v", KubeMarkMasqChain, utiliptables.TableNAT, KubePostroutingChain, err)
+		return
+	}
+}
+
+// getIPTablesMark returns the fwmark given the bit
+func getIPTablesMark(bit int) string {
+	value := 1 << uint(bit)
+	return fmt.Sprintf("%#08x/%#08x", value, value)
+}

pkg/kubelet/kubelet_network_others.go

@@ -0,0 +1,22 @@
+// +build !linux
+
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package kubelet
+
+// Do nothing.
+func (kl *Kubelet) syncNetworkUtil() {}

pkg/kubelet/kubelet_network_test.go

@@ -1,3 +1,5 @@
+// +build linux
+
 /*
 Copyright 2016 The Kubernetes Authors.