Use existing interface to request IP address during restore

libpod/container.go

@@ -128,6 +128,11 @@ type Container struct {
 
 	rootlessSlirpSyncR *os.File
 	rootlessSlirpSyncW *os.File
+
+	// A restored container should have the same IP address as before
+	// being checkpointed. If requestedIP is set it will be used instead
+	// of config.StaticIP.
+	requestedIP net.IP
 }
 
 // containerState contains the current state of the container

libpod/container_internal_linux.go

@@ -547,10 +547,8 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 			}
 		}
 		if IP != nil {
-			env := fmt.Sprintf("IP=%s", IP)
 			// Tell CNI which IP address we want.
-			os.Setenv("CNI_ARGS", env)
-			logrus.Debugf("Restoring container with %s", env)
+			c.requestedIP = IP
 		}
 	}
 
@@ -566,12 +564,6 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti
 		return err
 	}
 
-	// TODO: use existing way to request static IPs, once it is merged in ocicni
-	// https://github.com/cri-o/ocicni/pull/23/
-
-	// CNI_ARGS was used to request a certain IP address. Unconditionally remove it.
-	os.Unsetenv("CNI_ARGS")
-
 	// Read config
 	jsonPath := filepath.Join(c.bundlePath(), "config.json")
 	logrus.Debugf("generate.NewFromFile at %v", jsonPath)

libpod/networking_linux.go

@@ -50,7 +50,16 @@ func (r *Runtime) getPodNetwork(id, name, nsPath string, networks []string, port
 
 // Create and configure a new network namespace for a container
 func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Result, error) {
-	podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, ctr.config.StaticIP)
+	var requestedIP net.IP
+	if ctr.requestedIP != nil {
+		requestedIP = ctr.requestedIP
+		// cancel request for a specific IP in case the container is reused later
+		ctr.requestedIP = nil
+	} else {
+		requestedIP = ctr.config.StaticIP
+	}
+
+	podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, requestedIP)
 
 	results, err := r.netPlugin.SetUpPod(podNetwork)
 	if err != nil {
@@ -258,7 +267,16 @@ func (r *Runtime) teardownNetNS(ctr *Container) error {
 
 	logrus.Debugf("Tearing down network namespace at %s for container %s", ctr.state.NetNS.Path(), ctr.ID())
 
-	podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), ctr.config.Networks, ctr.config.PortMappings, ctr.config.StaticIP)
+	var requestedIP net.IP
+	if ctr.requestedIP != nil {
+		requestedIP = ctr.requestedIP
+		// cancel request for a specific IP in case the container is reused later
+		ctr.requestedIP = nil
+	} else {
+		requestedIP = ctr.config.StaticIP
+	}
+
+	podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctr.state.NetNS.Path(), ctr.config.Networks, ctr.config.PortMappings, requestedIP)
 
 	// The network may have already been torn down, so don't fail here, just log
 	if err := r.netPlugin.TearDownPod(podNetwork); err != nil {

test/e2e/checkpoint_test.go

@@ -199,14 +199,17 @@ var _ = Describe("Podman checkpoint", func() {
 	})
 
 	It("podman checkpoint container with established tcp connections", func() {
-		Skip("Seems to not work (yet) in CI")
 		podmanTest.RestoreArtifact(redis)
-		session := podmanTest.Podman([]string{"run", "-it", "--security-opt", "seccomp=unconfined", "--network", "host", "-d", redis})
+		session := podmanTest.Podman([]string{"run", "-it", "--security-opt", "seccomp=unconfined", "-d", redis})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
+		IP := podmanTest.Podman([]string{"inspect", "-l", "--format={{.NetworkSettings.IPAddress}}"})
+		IP.WaitWithDefaultTimeout()
+		Expect(IP.ExitCode()).To(Equal(0))
+
 		// Open a network connection to the redis server
-		conn, err := net.Dial("tcp", "127.0.0.1:6379")
+		conn, err := net.Dial("tcp", IP.OutputToString()+":6379")
 		if err != nil {
 			os.Exit(1)
 		}
@@ -287,4 +290,40 @@ var _ = Describe("Podman checkpoint", func() {
 		Expect(podmanTest.NumberOfContainersRunning()).To(Equal(0))
 	})
 
+	It("podman checkpoint and restore container with same IP", func() {
+		session := podmanTest.Podman([]string{"run", "-it", "--security-opt", "seccomp=unconfined", "--name", "test_name", "-d", ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		IPBefore := podmanTest.Podman([]string{"inspect", "-l", "--format={{.NetworkSettings.IPAddress}}"})
+		IPBefore.WaitWithDefaultTimeout()
+		Expect(IPBefore.ExitCode()).To(Equal(0))
+
+		result := podmanTest.Podman([]string{"container", "checkpoint", "test_name"})
+		result.WaitWithDefaultTimeout()
+
+		Expect(result.ExitCode()).To(Equal(0))
+		Expect(podmanTest.NumberOfContainersRunning()).To(Equal(0))
+		Expect(podmanTest.GetContainerStatus()).To(ContainSubstring("Exited"))
+
+		result = podmanTest.Podman([]string{"container", "restore", "test_name"})
+		result.WaitWithDefaultTimeout()
+
+		IPAfter := podmanTest.Podman([]string{"inspect", "-l", "--format={{.NetworkSettings.IPAddress}}"})
+		IPAfter.WaitWithDefaultTimeout()
+		Expect(IPAfter.ExitCode()).To(Equal(0))
+
+		// Check that IP address did not change between checkpointing and restoring
+		Expect(IPBefore.OutputToString()).To(Equal(IPAfter.OutputToString()))
+
+		Expect(result.ExitCode()).To(Equal(0))
+		Expect(podmanTest.NumberOfContainersRunning()).To(Equal(1))
+		Expect(podmanTest.GetContainerStatus()).To(ContainSubstring("Up"))
+
+		result = podmanTest.Podman([]string{"rm", "-fa"})
+		result.WaitWithDefaultTimeout()
+		Expect(result.ExitCode()).To(Equal(0))
+		Expect(podmanTest.NumberOfContainersRunning()).To(Equal(0))
+	})
+
 })