feat: Add "Containers" propery in the "nerdctl network inspect" command.

cmd/nerdctl/network/network_inspect.go

@@ -22,6 +22,7 @@ import (
 	"github.com/containerd/nerdctl/v2/cmd/nerdctl/completion"
 	"github.com/containerd/nerdctl/v2/cmd/nerdctl/helpers"
 	"github.com/containerd/nerdctl/v2/pkg/api/types"
+	"github.com/containerd/nerdctl/v2/pkg/clientutil"
 	"github.com/containerd/nerdctl/v2/pkg/cmd/network"
 )
 
@@ -59,13 +60,22 @@ func inspectAction(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	return network.Inspect(cmd.Context(), types.NetworkInspectOptions{
+
+	options := types.NetworkInspectOptions{
 		GOptions: globalOptions,
 		Mode:     mode,
 		Format:   format,
 		Networks: args,
 		Stdout:   cmd.OutOrStdout(),
-	})
+	}
+
+	client, ctx, cancel, err := clientutil.NewClient(cmd.Context(), options.GOptions.Namespace, options.GOptions.Address)
+	if err != nil {
+		return err
+	}
+	defer cancel()
+
+	return network.Inspect(ctx, client, options)
 }
 
 func networkInspectShellComplete(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {

cmd/nerdctl/network/network_inspect_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/containerd/nerdctl/mod/tigron/test"
 
 	"github.com/containerd/nerdctl/v2/pkg/inspecttypes/dockercompat"
+	"github.com/containerd/nerdctl/v2/pkg/testutil"
 	"github.com/containerd/nerdctl/v2/pkg/testutil/nerdtest"
 )
 
@@ -278,6 +279,42 @@ func TestNetworkInspect(t *testing.T) {
 				}
 			},
 		},
+		{
+			Description: "Verify that only active containers appear in the network inspect output",
+			Setup: func(data test.Data, helpers test.Helpers) {
+				helpers.Ensure("network", "create", data.Identifier("nginx-network-1"))
+				helpers.Ensure("network", "create", data.Identifier("nginx-network-2"))
+				helpers.Ensure("create", "--name", data.Identifier("nginx-container-1"), "--network", data.Identifier("nginx-network-1"), testutil.NginxAlpineImage)
+				helpers.Ensure("create", "--name", data.Identifier("nginx-container-2"), "--network", data.Identifier("nginx-network-1"), testutil.NginxAlpineImage)
+				helpers.Ensure("create", "--name", data.Identifier("nginx-container-on-diff-network"), "--network", data.Identifier("nginx-network-2"), testutil.NginxAlpineImage)
+				helpers.Ensure("start", data.Identifier("nginx-container-1"), data.Identifier("nginx-container-on-diff-network"))
+				data.Set("nginx-container-1-id", strings.Trim(helpers.Capture("inspect", data.Identifier("nginx-container-1"), "--format", "{{.Id}}"), "\n"))
+			},
+			Cleanup: func(data test.Data, helpers test.Helpers) {
+				helpers.Anyhow("rm", "-f", data.Identifier("nginx-container-1"))
+				helpers.Anyhow("rm", "-f", data.Identifier("nginx-container-2"))
+				helpers.Anyhow("rm", "-f", data.Identifier("nginx-container-on-diff-network"))
+				helpers.Anyhow("network", "remove", data.Identifier("nginx-network-1"))
+				helpers.Anyhow("network", "remove", data.Identifier("nginx-network-2"))
+			},
+			Command: func(data test.Data, helpers test.Helpers) test.TestableCommand {
+				return helpers.Command("network", "inspect", data.Identifier("nginx-network-1"))
+			},
+			Expected: func(data test.Data, helpers test.Helpers) *test.Expected {
+				return &test.Expected{
+					Output: func(stdout string, info string, t *testing.T) {
+						var dc []dockercompat.Network
+						err := json.Unmarshal([]byte(stdout), &dc)
+						assert.NilError(t, err, "Unable to unmarshal output\n"+info)
+						assert.Equal(t, 1, len(dc), "Unexpectedly got multiple results\n"+info)
+						assert.Equal(t, dc[0].Name, data.Identifier("nginx-network-1"))
+						// Assert only the "running" containers on the same network are returned.
+						assert.Equal(t, 1, len(dc[0].Containers), "Expected a single container as per configuration, but got multiple.")
+						assert.Equal(t, data.Identifier("nginx-container-1"), dc[0].Containers[data.Get("nginx-container-1-id")].Name)
+					},
+				}
+			},
+		},
 	}
 
 	testCase.Run(t)

pkg/cmd/network/inspect.go

@@ -22,16 +22,19 @@ import (
 	"errors"
 	"fmt"
 
+	containerd "github.com/containerd/containerd/v2/client"
 	"github.com/containerd/log"
 
 	"github.com/containerd/nerdctl/v2/pkg/api/types"
+	"github.com/containerd/nerdctl/v2/pkg/containerinspector"
 	"github.com/containerd/nerdctl/v2/pkg/formatter"
 	"github.com/containerd/nerdctl/v2/pkg/inspecttypes/dockercompat"
 	"github.com/containerd/nerdctl/v2/pkg/inspecttypes/native"
+	"github.com/containerd/nerdctl/v2/pkg/labels"
 	"github.com/containerd/nerdctl/v2/pkg/netutil"
 )
 
-func Inspect(ctx context.Context, options types.NetworkInspectOptions) error {
+func Inspect(ctx context.Context, client *containerd.Client, options types.NetworkInspectOptions) error {
 	if options.Mode != "native" && options.Mode != "dockercompat" {
 		return fmt.Errorf("unknown mode %q", options.Mode)
 	}
@@ -53,12 +56,35 @@ func Inspect(ctx context.Context, options types.NetworkInspectOptions) error {
 			errs = append(errs, fmt.Errorf("no network found matching: %s", req))
 			continue
 		}
+
 		network := netList[0]
+		var filters = []string{fmt.Sprintf("labels.%q==%q", labels.Networks, []string{network.Name})}
+
+		filteredContainers, err := client.Containers(ctx, filters...)
+
+		if err != nil {
+			return err
+		}
+
+		var containers []*native.Container
+
+		for _, container := range filteredContainers {
+			nativeContainer, err := containerinspector.Inspect(ctx, container)
+			if err != nil {
+				continue
+			}
+			if nativeContainer.Process == nil || nativeContainer.Process.Status.Status != containerd.Running {
+				continue
+			}
+			containers = append(containers, nativeContainer)
+		}
+
 		r := &native.Network{
 			CNI:           json.RawMessage(network.Bytes),
 			NerdctlID:     network.NerdctlID,
 			NerdctlLabels: network.NerdctlLabels,
 			File:          network.File,
+			Containers:    containers,
 		}
 		switch options.Mode {
 		case "native":

pkg/inspecttypes/dockercompat/dockercompat.go

@@ -884,13 +884,22 @@ type IPAM struct {
 // Network mimics a `docker network inspect` object.
 // From https://github.com/moby/moby/blob/v20.10.7/api/types/types.go#L430-L448
 type Network struct {
-	Name   string            `json:"Name"`
-	ID     string            `json:"Id,omitempty"` // optional in nerdctl
-	IPAM   IPAM              `json:"IPAM,omitempty"`
-	Labels map[string]string `json:"Labels"`
+	Name       string                      `json:"Name"`
+	ID         string                      `json:"Id,omitempty"` // optional in nerdctl
+	IPAM       IPAM                        `json:"IPAM,omitempty"`
+	Labels     map[string]string           `json:"Labels"`
+	Containers map[string]EndpointResource `json:"Containers"` // Containers contains endpoints belonging to the network
 	// Scope, Driver, etc. are omitted
 }
 
+type EndpointResource struct {
+	Name        string
+	EndpointID  string
+	MacAddress  string
+	IPv4Address string
+	IPv6Address string
+}
+
 type structuredCNI struct {
 	Name    string `json:"name"`
 	Plugins []struct {
@@ -930,6 +939,17 @@ func NetworkFromNative(n *native.Network) (*Network, error) {
 		res.Labels = *n.NerdctlLabels
 	}
 
+	res.Containers = make(map[string]EndpointResource)
+	for _, container := range n.Containers {
+		res.Containers[container.ID] = EndpointResource{
+			Name: container.Labels[labels.Name],
+			// EndpointID:  container.EndpointID,
+			// MacAddress:  container.MacAddress,
+			// IPv4Address: container.IPv4Address,
+			// IPv6Address: container.IPv6Address,
+		}
+	}
+
 	return &res, nil
 }
 

pkg/inspecttypes/native/network.go

@@ -16,12 +16,15 @@
 
 package native
 
-import "encoding/json"
+import (
+	"encoding/json"
+)
 
-// Network corresponds to pkg/netutil.NetworkConfigList
+// Network corresponds to pkg/netutil.NetworkConfig
 type Network struct {
 	CNI           json.RawMessage    `json:"CNI,omitempty"`
 	NerdctlID     *string            `json:"NerdctlID"`
 	NerdctlLabels *map[string]string `json:"NerdctlLabels,omitempty"`
 	File          string             `json:"File,omitempty"`
+	Containers    []*Container       `json:"Containers"`
 }