fix: restore update network settings for dockercompat (runfinch#286)

Signed-off-by: shubhranshu153 <shubhum@amazon.com>

Author: Shubhranshu153

internal/service/container/inspect.go

@@ -5,11 +5,18 @@ package container
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"strconv"
+	"strings"
 
+	"github.com/containerd/nerdctl/v2/pkg/inspecttypes/dockercompat"
+	"github.com/containerd/nerdctl/v2/pkg/labels"
 	"github.com/runfinch/finch-daemon/api/types"
 )
 
+const networkPrefix = "unknown-eth"
+
 func (s *service) Inspect(ctx context.Context, cid string, sizeFlag bool) (*types.Container, error) {
 	c, err := s.getContainer(ctx, cid)
 	if err != nil {
@@ -58,6 +65,12 @@ func (s *service) Inspect(ctx context.Context, cid string, sizeFlag bool) (*type
 		Labels:       inspect.Config.Labels,
 	}
 
+	l, err := c.Labels(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get container labels: %s", err)
+	}
+	updateNetworkSettings(ctx, cont.NetworkSettings, l)
+
 	// make sure it passes the default time value for time fields otherwise the goclient fails.
 	if inspect.Created == "" {
 		cont.Created = "0001-01-01T00:00:00Z"
@@ -69,3 +82,46 @@ func (s *service) Inspect(ctx context.Context, cid string, sizeFlag bool) (*type
 
 	return &cont, nil
 }
+
+// updateNetworkSettings updates the settings in the network to match that
+// of docker as docker identifies networks by their name in "NetworkSettings",
+// but nerdctl uses a sequential ordering "unknown-eth0", "unknown-eth1",...
+// we use container labels to find corresponding name for each network in "NetworkSettings".
+func updateNetworkSettings(ctx context.Context, ns *dockercompat.NetworkSettings, labels map[string]string) error {
+	if ns != nil && ns.Networks != nil {
+		networks := map[string]*dockercompat.NetworkEndpointSettings{}
+
+		for network, settings := range ns.Networks {
+			networkName := getNetworkName(labels, network)
+			networks[networkName] = settings
+		}
+		ns.Networks = networks
+	}
+	return nil
+}
+
+// getNetworkName gets network name from container labels using the index specified by the network prefix.
+// returns the default prefix if network name was not found.
+func getNetworkName(lab map[string]string, network string) string {
+	namesJSON, ok := lab[labels.Networks]
+	if !ok {
+		return network
+	}
+	var names []string
+	if err := json.Unmarshal([]byte(namesJSON), &names); err != nil {
+		return network
+	}
+
+	if strings.HasPrefix(network, networkPrefix) {
+		prefixLen := len(networkPrefix)
+		index, err := strconv.ParseUint(network[prefixLen:], 10, 64)
+		if err != nil {
+			return network
+		}
+		if int(index) < len(names) {
+			return names[index]
+		}
+	}
+
+	return network
+}

internal/service/container/inspect_test.go

@@ -86,8 +86,10 @@ var _ = Describe("Container Inspect API ", func() {
 
 			ncClient.EXPECT().InspectContainer(gomock.Any(), con, sizeFlag).Return(
 				&inspect, nil)
-
+			
+			con.EXPECT().Labels(gomock.Any()).Return(nil, nil)
 			result, err := service.Inspect(ctx, cid, sizeFlag)
+
 			Expect(*result).Should(Equal(ret))
 			Expect(err).Should(BeNil())
 		})
@@ -153,7 +155,8 @@ var _ = Describe("Container Inspect API ", func() {
 
 			ncClient.EXPECT().InspectContainer(gomock.Any(), con, sizeFlag).Return(
 				&inspectWithSize, nil)
-
+			
+			con.EXPECT().Labels(gomock.Any()).Return(nil, nil)
 			result, err := service.Inspect(ctx, cid, sizeFlag)
 			Expect(err).Should(BeNil())
 			Expect(result.SizeRw).ShouldNot(BeNil())
@@ -170,7 +173,8 @@ var _ = Describe("Container Inspect API ", func() {
 
 			ncClient.EXPECT().InspectContainer(gomock.Any(), con, sizeFlag).Return(
 				&inspect, nil)
-
+			
+			con.EXPECT().Labels(gomock.Any()).Return(nil, nil)
 			result, err := service.Inspect(ctx, cid, sizeFlag)
 			Expect(err).Should(BeNil())
 			Expect(result.SizeRw).Should(BeZero())

internal/service/container/list.go

@@ -42,6 +42,12 @@ func (s *service) List(ctx context.Context, listOpts ncTypes.ContainerListOption
 			Mounts:          ci.Mounts,
 		}
 
+		l, err := c.Labels(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get container labels: %s", err)
+		}
+		updateNetworkSettings(ctx, cli.NetworkSettings, l)
+
 		containers = append(containers, cli)
 	}
 	return containers, nil