Expose network interfaces via runc events

The libcontainer network statistics are unreachable without manually
creating a libcontainer instance. To retrieve them via the CLI interface
of runc, we now expose them as well.

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

events.go

@@ -163,6 +163,7 @@ func convertLibcontainerStats(ls *libcontainer.Stats) *types.Stats {
 		}
 	}
 
+	s.NetworkInterfaces = ls.Interfaces
 	return &s
 }
 

libcontainer/network_linux.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/opencontainers/runc/libcontainer/configs"
+	"github.com/opencontainers/runc/types"
 	"github.com/vishvananda/netlink"
 )
 
@@ -37,8 +38,8 @@ func getStrategy(tpe string) (networkStrategy, error) {
 }
 
 // Returns the network statistics for the network interfaces represented by the NetworkRuntimeInfo.
-func getNetworkInterfaceStats(interfaceName string) (*NetworkInterface, error) {
-	out := &NetworkInterface{Name: interfaceName}
+func getNetworkInterfaceStats(interfaceName string) (*types.NetworkInterface, error) {
+	out := &types.NetworkInterface{Name: interfaceName}
 	// This can happen if the network runtime information is missing - possible if the
 	// container was created by an old version of libcontainer.
 	if interfaceName == "" {

libcontainer/stats.go

@@ -1,15 +0,0 @@
-package libcontainer
-
-type NetworkInterface struct {
-	// Name is the name of the network interface.
-	Name string
-
-	RxBytes   uint64
-	RxPackets uint64
-	RxErrors  uint64
-	RxDropped uint64
-	TxBytes   uint64
-	TxPackets uint64
-	TxErrors  uint64
-	TxDropped uint64
-}

libcontainer/stats_linux.go

@@ -1,10 +1,13 @@
 package libcontainer
 
-import "github.com/opencontainers/runc/libcontainer/cgroups"
-import "github.com/opencontainers/runc/libcontainer/intelrdt"
+import (
+	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/opencontainers/runc/libcontainer/intelrdt"
+	"github.com/opencontainers/runc/types"
+)
 
 type Stats struct {
-	Interfaces    []*NetworkInterface
+	Interfaces    []*types.NetworkInterface
 	CgroupStats   *cgroups.Stats
 	IntelRdtStats *intelrdt.Stats
 }

types/events.go

@@ -9,12 +9,13 @@ type Event struct {
 
 // stats is the runc specific stats structure for stability when encoding and decoding stats.
 type Stats struct {
-	CPU      Cpu                `json:"cpu"`
-	Memory   Memory             `json:"memory"`
-	Pids     Pids               `json:"pids"`
-	Blkio    Blkio              `json:"blkio"`
-	Hugetlb  map[string]Hugetlb `json:"hugetlb"`
-	IntelRdt IntelRdt           `json:"intel_rdt"`
+	CPU               Cpu                 `json:"cpu"`
+	Memory            Memory              `json:"memory"`
+	Pids              Pids                `json:"pids"`
+	Blkio             Blkio               `json:"blkio"`
+	Hugetlb           map[string]Hugetlb  `json:"hugetlb"`
+	IntelRdt          IntelRdt            `json:"intel_rdt"`
+	NetworkInterfaces []*NetworkInterface `json:"network_interfaces"`
 }
 
 type Hugetlb struct {
@@ -113,3 +114,17 @@ type IntelRdt struct {
 	// The memory bandwidth schema in 'container_id' group
 	MemBwSchema string `json:"mem_bw_schema,omitempty"`
 }
+
+type NetworkInterface struct {
+	// Name is the name of the network interface.
+	Name string
+
+	RxBytes   uint64
+	RxPackets uint64
+	RxErrors  uint64
+	RxDropped uint64
+	TxBytes   uint64
+	TxPackets uint64
+	TxErrors  uint64
+	TxDropped uint64
+}