Retrieve network inspect info from dependency container

When a container either joins a pod that shares the network
namespace or uses `--net=container:` to share the network
namespace of another container, it does not have its own copy of
the CNI results used to generate `podman inspect` output. As
such, to inspect these containers, we should be going to the
container we share the namespace with for network info.

Fixes containers#8073

Signed-off-by: Matthew Heon <[email protected]>

libpod/networking_linux.go

@@ -823,6 +823,20 @@ func getContainerNetIO(ctr *Container) (*netlink.LinkStatistics, error) {
 // Produce an InspectNetworkSettings containing information on the container
 // network.
 func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, error) {
+	if c.config.NetNsCtr != "" {
+		netNsCtr, err := c.runtime.GetContainer(c.config.NetNsCtr)
+		if err != nil {
+			return nil, err
+		}
+		// Have to sync to ensure that state is populated
+		if err := netNsCtr.syncContainer(); err != nil {
+			return nil, err
+		}
+		logrus.Debugf("Container %s shares network namespace, retrieving network info of container %s", c.ID(), c.config.NetNsCtr)
+
+		return netNsCtr.getContainerNetworkInfo()
+	}
+
 	settings := new(define.InspectNetworkSettings)
 	settings.Ports = makeInspectPortBindings(c.config.PortMappings)
 

test/e2e/pod_create_test.go

@@ -245,6 +245,24 @@ var _ = Describe("Podman pod create", func() {
 		}
 	})
 
+	It("podman container in pod with IP address shares IP address", func() {
+		SkipIfRootless("Rootless does not support --ip")
+		podName := "test"
+		ctrName := "testCtr"
+		ip := GetRandomIPAddress()
+		podCreate := podmanTest.Podman([]string{"pod", "create", "--ip", ip, "--name", podName})
+		podCreate.WaitWithDefaultTimeout()
+		Expect(podCreate.ExitCode()).To(Equal(0))
+		podCtr := podmanTest.Podman([]string{"run", "--name", ctrName, "--pod", podName, "-d", "-t", ALPINE, "top"})
+		podCtr.WaitWithDefaultTimeout()
+		Expect(podCtr.ExitCode()).To(Equal(0))
+		ctrInspect := podmanTest.Podman([]string{"inspect", ctrName})
+		ctrInspect.WaitWithDefaultTimeout()
+		Expect(ctrInspect.ExitCode()).To(Equal(0))
+		ctrJSON := ctrInspect.InspectContainerToJSON()
+		Expect(ctrJSON[0].NetworkSettings.IPAddress).To(Equal(ip))
+	})
+
 	It("podman create pod with IP address and no infra should fail", func() {
 		name := "test"
 		ip := GetRandomIPAddress()