podman stats: work with network connect/disconnect

libpod/networking_linux.go

@@ -930,6 +930,8 @@ func (r *Runtime) reloadContainerNetwork(ctr *Container) (map[string]types.Statu
 	return r.configureNetNS(ctr, ctr.state.NetNS)
 }
 
+// TODO (5.0): return the statistics per network interface
+// This would allow better compat with docker.
 func getContainerNetIO(ctr *Container) (*netlink.LinkStatistics, error) {
 	var netStats *netlink.LinkStatistics
 
@@ -943,21 +945,39 @@ func getContainerNetIO(ctr *Container) (*netlink.LinkStatistics, error) {
 		return nil, nil
 	}
 
-	// FIXME get the interface from the container netstatus
-	dev := "eth0"
 	netMode := ctr.config.NetMode
+	netStatus := ctr.getNetworkStatus()
 	if otherCtr != nil {
 		netMode = otherCtr.config.NetMode
+		netStatus = otherCtr.getNetworkStatus()
 	}
 	if netMode.IsSlirp4netns() {
-		dev = "tap0"
+		// create a fake status with correct interface name for the logic below
+		netStatus = map[string]types.StatusBlock{
+			"slirp4netns": {
+				Interfaces: map[string]types.NetInterface{"tap0": {}},
+			},
+		}
 	}
 	err := ns.WithNetNSPath(netNSPath, func(_ ns.NetNS) error {
-		link, err := netlink.LinkByName(dev)
-		if err != nil {
-			return err
+		for _, status := range netStatus {
+			for dev := range status.Interfaces {
+				link, err := netlink.LinkByName(dev)
+				if err != nil {
+					return err
+				}
+				if netStats == nil {
+					netStats = link.Attrs().Statistics
+					continue
+				}
+				// Currently only Tx/RxBytes are used.
+				// In the future we should return all stats per interface so that
+				// api users have a better options.
+				stats := link.Attrs().Statistics
+				netStats.TxBytes += stats.TxBytes
+				netStats.RxBytes += stats.RxBytes
+			}
 		}
-		netStats = link.Attrs().Statistics
 		return nil
 	})
 	return netStats, err

test/e2e/network_connect_disconnect_test.go

@@ -114,6 +114,11 @@ var _ = Describe("Podman network connect and disconnect", func() {
 		exec3.WaitWithDefaultTimeout()
 		Expect(exec3).Should(Exit(0))
 		Expect(strings.Contains(exec3.OutputToString(), ns)).To(BeFalse())
+
+		// make sure stats still works /~https://github.com/containers/podman/issues/13824
+		stats := podmanTest.Podman([]string{"stats", "test", "--no-stream"})
+		stats.WaitWithDefaultTimeout()
+		Expect(stats).Should(Exit(0))
 	})
 
 	It("bad network name in connect should result in error", func() {
@@ -237,6 +242,11 @@ var _ = Describe("Podman network connect and disconnect", func() {
 		Expect(exec3).Should(Exit(0))
 		Expect(strings.Contains(exec3.OutputToString(), ns)).To(BeTrue())
 
+		// make sure stats works /~https://github.com/containers/podman/issues/13824
+		stats := podmanTest.Podman([]string{"stats", "test", "--no-stream"})
+		stats.WaitWithDefaultTimeout()
+		Expect(stats).Should(Exit(0))
+
 		// make sure no logrus errors are shown /~https://github.com/containers/podman/issues/9602
 		rm := podmanTest.Podman([]string{"rm", "--time=0", "-f", "test"})
 		rm.WaitWithDefaultTimeout()