metis: implement CNI

go.work.sum

@@ -1,6 +1,7 @@
 cloud.google.com/go v0.115.1 h1:Jo0SM9cQnSkYfp44+v+NQXHpcHqlnRJk2qxh6yvxxxQ=
 cloud.google.com/go/compute v1.23.1 h1:V97tBoDaZHb6leicZ1G6DLK2BAaZLJ/7+9BB/En3hR0=
 github.com/google/pprof v0.0.0-20250403155104-27863c87afa6/go.mod h1:boTsfXsheKC2y+lKOCMpSfarhxDeIzfZG1jqGcPl3cA=
-github.com/google/pprof v0.0.0-20250820193118-f64d9cf942d6/go.mod h1:I6V7YzU0XDpsHqbsyrghnFZLO1gwK6NPTNvmetQIk9U=
-github.com/onsi/gomega v1.38.2/go.mod h1:W2MJcYxRGV63b418Ai34Ud0hEdTVXq9NW9+Sx6uXf3k=
 github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/vishvananda/netns v0.0.5 h1:DfiHV+j8bA32MFM7bfEunvT8IAqQ/NzSJHtcmW5zdEY=
+github.com/vishvananda/netns v0.0.5/go.mod h1:SpkAiCQRtJ6TvvxPnOSyH3BMl6unz3xZlaprSwhNNJM=
+golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

metis/cmd/cni.go

@@ -0,0 +1,215 @@
+/*
+Copyright 2026 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 main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net"
+	"path/filepath"
+	"time"
+
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/pkg/types"
+	current "github.com/containernetworking/cni/pkg/types/100"
+	"github.com/containernetworking/cni/pkg/version"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+
+	pb "k8s.io/metis/api/adaptiveipam/v1"
+)
+
+// NetConf extends standard CNI network configuration.
+type NetConf struct {
+	types.NetConf
+	DaemonSocket   string `json:"daemon_socket"`
+	InitialPodCIDR string `json:"initial_pod_cidr"`
+}
+
+// K8sArgs contains the standard Kubernetes CNI arguments.
+type K8sArgs struct {
+	types.CommonArgs
+	K8S_POD_NAME      types.UnmarshallableString `json:"K8S_POD_NAME"`
+	K8S_POD_NAMESPACE types.UnmarshallableString `json:"K8S_POD_NAMESPACE"`
+}
+
+const defaultDaemonSocket = "/var/run/metis.sock"
+
+var clientFactory = getGrpcClient
+
+func loadNetConf(bytes []byte) (*NetConf, error) {
+	conf := &NetConf{
+		DaemonSocket: defaultDaemonSocket,
+	}
+	if err := json.Unmarshal(bytes, conf); err != nil {
+		return nil, fmt.Errorf("failed to parse network configuration: %v", err)
+	}
+	return conf, nil
+}
+
+func loadK8sArgs(args string) (*K8sArgs, error) {
+	k8sArgs := &K8sArgs{}
+	if err := types.LoadArgs(args, k8sArgs); err != nil {
+		return nil, fmt.Errorf("failed to parse CNI args: %v", err)
+	}
+	return k8sArgs, nil
+}
+
+func getGrpcClient(socketPath string) (pb.AdaptiveIpamClient, *grpc.ClientConn, error) {
+	dialOption := grpc.WithTransportCredentials(insecure.NewCredentials())
+
+	absPath, err := filepath.Abs(socketPath)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get absolute path for socket %s: %v", socketPath, err)
+	}
+	dialTarget := fmt.Sprintf("unix://%s", absPath)
+
+	conn, err := grpc.NewClient(dialTarget, dialOption)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to connect to daemon: %v", err)
+	}
+
+	return pb.NewAdaptiveIpamClient(conn), conn, nil
+}
+
+func cmdAdd(args *skel.CmdArgs) error {
+	conf, err := loadNetConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	k8sArgs, err := loadK8sArgs(args.Args)
+	if err != nil {
+		return err
+	}
+
+	client, conn, err := clientFactory(conf.DaemonSocket)
+	if err != nil {
+		return err
+	}
+	if conn != nil {
+		defer conn.Close()
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	req := &pb.AllocatePodIPRequest{
+		Network: conf.Name,
+		Ipv4Config: &pb.IPConfig{
+			InterfaceName:  args.IfName,
+			ContainerId:    args.ContainerID,
+			InitialPodCidr: conf.InitialPodCIDR,
+		},
+		PodName:      string(k8sArgs.K8S_POD_NAME),
+		PodNamespace: string(k8sArgs.K8S_POD_NAMESPACE),
+	}
+
+	resp, err := client.AllocatePodIP(ctx, req)
+	if err != nil {
+		return fmt.Errorf("failed to allocate IP via daemon: %v", err)
+	}
+
+	result := &current.Result{
+		CNIVersion: conf.CNIVersion,
+	}
+
+	if resp.Ipv4 != nil {
+		_, ipNet, err := net.ParseCIDR(resp.Ipv4.Cidr)
+		if err != nil {
+			return fmt.Errorf("failed to parse allocated CIDR: %v", err)
+		}
+		ip := net.ParseIP(resp.Ipv4.IpAddress)
+
+		result.IPs = append(result.IPs, &current.IPConfig{
+			Address: net.IPNet{IP: ip, Mask: ipNet.Mask},
+		})
+	}
+
+	// TODO: Handle IPv6 if needed
+
+	return types.PrintResult(result, conf.CNIVersion)
+}
+
+func cmdDel(args *skel.CmdArgs) error {
+	conf, err := loadNetConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	k8sArgs, err := loadK8sArgs(args.Args)
+	if err != nil {
+		return err
+	}
+
+	client, conn, err := clientFactory(conf.DaemonSocket)
+	if err != nil {
+		return err
+	}
+	if conn != nil {
+		defer conn.Close()
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	req := &pb.DeallocatePodIPRequest{
+		Network:       conf.Name,
+		InterfaceName: args.IfName,
+		ContainerId:   args.ContainerID,
+		PodName:       string(k8sArgs.K8S_POD_NAME),
+		PodNamespace:  string(k8sArgs.K8S_POD_NAMESPACE),
+	}
+
+	_, err = client.DeallocatePodIP(ctx, req)
+	if err != nil {
+		return fmt.Errorf("failed to deallocate IP via daemon: %v", err)
+	}
+
+	return nil
+}
+
+func cmdCheck(args *skel.CmdArgs) error {
+	conf, err := loadNetConf(args.StdinData)
+	if err != nil {
+		return err
+	}
+
+	// For check, we just verify we can connect to the daemon
+	_, conn, err := clientFactory(conf.DaemonSocket)
+	if err != nil {
+		return err
+	}
+	if conn != nil {
+		defer conn.Close()
+	}
+
+	return nil
+}
+
+func RunCni() {
+	skel.PluginMainFuncs(
+		skel.CNIFuncs{
+			Add:   cmdAdd,
+			Check: cmdCheck,
+			Del:   cmdDel,
+		},
+		version.All,
+		"metis CNI plugin",
+	)
+}