Allow to configure the nftables name and implement defaulting in the config data structure

pkg/networkpolicy/controller.go

@@ -3,6 +3,7 @@ package networkpolicy
 import (
 	"context"
 	"fmt"
+	"os"
 	"time"
 
 	nfqueue "github.com/florianl/go-nfqueue"
@@ -67,6 +68,24 @@ type Config struct {
 	QueueID                    int
 	NodeName                   string
 	NetfilterBug1766Fix        bool
+	NFTableName                string // if other projects use this controllers they need to be able to use their own table name
+}
+
+func (c *Config) Defaults() error {
+	var err error
+	if c.QueueID == 0 {
+		c.QueueID = 100
+	}
+	if c.NodeName == "" {
+		c.NodeName, err = os.Hostname()
+		if err != nil {
+			return err
+		}
+	}
+	if c.NFTableName == "" {
+		c.NFTableName = "kube-network-policies"
+	}
+	return nil
 }
 
 // NewController returns a new *Controller.
@@ -80,8 +99,12 @@ func NewController(client clientset.Interface,
 	baselineAdminNetworkPolicyInformer policyinformers.BaselineAdminNetworkPolicyInformer,
 	config Config,
 ) (*Controller, error) {
+	err := config.Defaults()
+	if err != nil {
+		return nil, err
+	}
 	klog.V(2).Info("Initializing nftables")
-	nft, err := knftables.New(knftables.InetFamily, "kube-network-policies")
+	nft, err := knftables.New(knftables.InetFamily, config.NFTableName)
 	if err != nil {
 		return nil, err
 	}

pkg/networkpolicy/controller_test.go

@@ -1,6 +1,8 @@
 package networkpolicy
 
 import (
+	"testing"
+
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/informers"
@@ -125,3 +127,70 @@ func newTestController() *networkpolicyController {
 		informersFactory.Core().V1().Nodes().Informer().GetStore(),
 	}
 }
+
+func TestConfig_Defaults(t *testing.T) {
+	tests := []struct {
+		name     string
+		config   Config
+		expected Config
+	}{
+		{
+			name: "empty",
+			config: Config{
+				NodeName: "testnode", // nodename defaults to os.Hostname so we ignore for tests
+			},
+			expected: Config{
+				FailOpen:                   false,
+				AdminNetworkPolicy:         false,
+				BaselineAdminNetworkPolicy: false,
+				QueueID:                    100,
+				NodeName:                   "testnode", // nodename defaults to os.Hostname so we ignore for tests
+				NetfilterBug1766Fix:        false,
+				NFTableName:                "kube-network-policies",
+			},
+		}, {
+			name: "queue id",
+			config: Config{
+				NodeName: "testnode", // nodename defaults to os.Hostname so we ignore for tests
+				QueueID:  99,
+			},
+			expected: Config{
+				FailOpen:                   false,
+				AdminNetworkPolicy:         false,
+				BaselineAdminNetworkPolicy: false,
+				QueueID:                    99,
+				NodeName:                   "testnode", // nodename defaults to os.Hostname so we ignore for tests
+				NetfilterBug1766Fix:        false,
+				NFTableName:                "kube-network-policies",
+			},
+		}, {
+			name: "table name",
+			config: Config{
+				NodeName:    "testnode", // nodename defaults to os.Hostname so we ignore for tests
+				QueueID:     99,
+				NFTableName: "kindnet-network-policies",
+			},
+			expected: Config{
+				FailOpen:                   false,
+				AdminNetworkPolicy:         false,
+				BaselineAdminNetworkPolicy: false,
+				QueueID:                    99,
+				NodeName:                   "testnode", // nodename defaults to os.Hostname so we ignore for tests
+				NetfilterBug1766Fix:        false,
+				NFTableName:                "kindnet-network-policies",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := tt.config
+			if err := c.Defaults(); err != nil {
+				t.Errorf("Config.Defaults() error = %v", err)
+			}
+
+			if c != tt.expected {
+				t.Errorf("Config.Defaults() = %v, want %v", c, tt.expected)
+			}
+		})
+	}
+}