Merge pull request #4385 from haytok/followup_of_issue_4027

fix: allow storing additional network info in network-config.json

Author: AkihiroSuda

docs/dir.md

@@ -35,7 +35,7 @@ Files:
 - `<CID>-json.log`: used by `nerdctl logs`
 - `oci-hook.*.log`: logs of the OCI hook
 - `lifecycle.json`: used to store stateful information about the container that can only be retrieved through OCI hooks
-- `network-config.json`: used to store port mapping information for containers run with the `-p` option.
+- `network-config.json`: used to store container-specific network configuration, such as port mappings.
 
 ### `<DATAROOT>/<ADDRHASH>/names/<NAMESPACE>`
 e.g. `/var/lib/nerdctl/1935db59/names/default`

pkg/cmd/container/create.go

@@ -59,6 +59,7 @@ import (
 	"github.com/containerd/nerdctl/v2/pkg/maputil"
 	"github.com/containerd/nerdctl/v2/pkg/mountutil"
 	"github.com/containerd/nerdctl/v2/pkg/namestore"
+	"github.com/containerd/nerdctl/v2/pkg/netutil/networkstore"
 	"github.com/containerd/nerdctl/v2/pkg/platformutil"
 	"github.com/containerd/nerdctl/v2/pkg/portutil"
 	"github.com/containerd/nerdctl/v2/pkg/referenceutil"
@@ -390,7 +391,10 @@ func Create(ctx context.Context, client *containerd.Client, args []string, netMa
 	}
 	cOpts = append(cOpts, ilOpt)
 
-	err = portutil.GeneratePortMappingsConfig(dataStore, options.GOptions.Namespace, id, netLabelOpts.PortMappings)
+	netConf := networkstore.NetworkConfig{
+		PortMappings: netLabelOpts.PortMappings,
+	}
+	err = portutil.StoreNetworkConfig(dataStore, options.GOptions.Namespace, id, netConf)
 	if err != nil {
 		return nil, generateRemoveOrphanedDirsFunc(ctx, id, dataStore, internalLabels), fmt.Errorf("Error writing to network-config.json: %v", err)
 	}

pkg/netutil/networkstore/networkstore.go

@@ -55,26 +55,30 @@ func New(dataStore, namespace, containerID string) (ns *NetworkStore, err error)
 	}, nil
 }
 
+type NetworkConfig struct {
+	PortMappings []cni.PortMapping `json:"portMappings,omitempty"`
+}
+
 type NetworkStore struct {
 	safeStore store.Store
 
-	PortMappings []cni.PortMapping
+	NetConf NetworkConfig
 }
 
-func (ns *NetworkStore) Acquire(portMappings []cni.PortMapping) (err error) {
+func (ns *NetworkStore) Acquire(netConf NetworkConfig) (err error) {
 	defer func() {
 		if err != nil {
 			err = errors.Join(ErrNetworkStore, err)
 		}
 	}()
 
-	portsJSON, err := json.Marshal(portMappings)
+	netConfJSON, err := json.Marshal(netConf)
 	if err != nil {
-		return fmt.Errorf("failed to marshal port mappings to JSON: %w", err)
+		return fmt.Errorf("failed to marshal network config to JSON: %w", err)
 	}
 
 	return ns.safeStore.WithLock(func() error {
-		return ns.safeStore.Set(portsJSON, networkConfigName)
+		return ns.safeStore.Set(netConfJSON, networkConfigName)
 	})
 }
 
@@ -99,11 +103,11 @@ func (ns *NetworkStore) Load() (err error) {
 			return err
 		}
 
-		var ports []cni.PortMapping
-		if err := json.Unmarshal(data, &ports); err != nil {
-			return fmt.Errorf("failed to parse port mappings %v: %w", ports, err)
+		var netConf NetworkConfig
+		if err := json.Unmarshal(data, &netConf); err != nil {
+			return fmt.Errorf("failed to parse network config %v: %w", netConf, err)
 		}
-		ns.PortMappings = ports
+		ns.NetConf = netConf
 
 		return err
 	})

pkg/portutil/portutil.go

@@ -140,12 +140,12 @@ func ParseFlagP(s string) ([]cni.PortMapping, error) {
 	return mr, nil
 }
 
-func GeneratePortMappingsConfig(dataStore, namespace, id string, portMappings []cni.PortMapping) error {
+func StoreNetworkConfig(dataStore, namespace, id string, netConf networkstore.NetworkConfig) error {
 	ns, err := networkstore.New(dataStore, namespace, id)
 	if err != nil {
 		return err
 	}
-	return ns.Acquire(portMappings)
+	return ns.Acquire(netConf)
 }
 
 func LoadPortMappings(dataStore, namespace, id string, containerLabels map[string]string) ([]cni.PortMapping, error) {
@@ -158,8 +158,8 @@ func LoadPortMappings(dataStore, namespace, id string, containerLabels map[strin
 	if err = ns.Load(); err != nil {
 		return ports, err
 	}
-	if len(ns.PortMappings) != 0 {
-		return ns.PortMappings, nil
+	if len(ns.NetConf.PortMappings) != 0 {
+		return ns.NetConf.PortMappings, nil
 	}
 
 	portsJSON := containerLabels[labels.Ports]