Sync the iptables/nftables usage with acl logic (#1017)

client/internal/routemanager/iptables_linux.go

@@ -49,6 +49,28 @@ type iptablesManager struct {
 	mux        sync.Mutex
 }
 
+func newIptablesManager(parentCtx context.Context) *iptablesManager {
+	ctx, cancel := context.WithCancel(parentCtx)
+	ipv4Client, _ := iptables.NewWithProtocol(iptables.ProtocolIPv4)
+	if !isIptablesClientAvailable(ipv4Client) {
+		log.Infof("iptables is missing for ipv4")
+		ipv4Client = nil
+	}
+	ipv6Client, _ := iptables.NewWithProtocol(iptables.ProtocolIPv6)
+	if !isIptablesClientAvailable(ipv6Client) {
+		log.Infof("iptables is missing for ipv6")
+		ipv6Client = nil
+	}
+
+	return &iptablesManager{
+		ctx:        ctx,
+		stop:       cancel,
+		ipv4Client: ipv4Client,
+		ipv6Client: ipv6Client,
+		rules:      make(map[string]map[string][]string),
+	}
+}
+
 // CleanRoutingRules cleans existing iptables resources that we created by the agent
 func (i *iptablesManager) CleanRoutingRules() {
 	i.mux.Lock()
@@ -453,3 +475,8 @@ func getIptablesRuleType(table string) string {
 	}
 	return ruleType
 }
+
+func isIptablesClientAvailable(client *iptables.IPTables) bool {
+	_, err := client.ListChains("filter")
+	return err == nil
+}