Merge pull request #8203 from Luap99/fix-8194

Fix dnsname when joining a different network namespace in a pod

libpod/networking_linux.go

@@ -102,17 +102,7 @@ func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Re
 		requestedMAC = ctr.config.StaticMAC
 	}
 
-	// If we are in a pod use the pod name for the network, otherwise the container name
-	var podName string
-	if ctr.PodID() != "" {
-		pod, err := r.GetPod(ctr.PodID())
-		if err == nil {
-			podName = pod.Name()
-		}
-	}
-	if podName == "" {
-		podName = ctr.Name()
-	}
+	podName := getCNIPodName(ctr)
 
 	podNetwork := r.getPodNetwork(ctr.ID(), podName, ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, requestedIP, requestedMAC)
 

libpod/rootless_cni_linux.go

@@ -53,7 +53,7 @@ func AllocRootlessCNI(ctx context.Context, c *Container) (ns.NetNS, []*cnitypes.
 	if err != nil {
 		return nil, nil, err
 	}
-	k8sPodName := getPodOrContainerName(c) // passed to CNI as K8S_POD_NAME
+	k8sPodName := getCNIPodName(c) // passed to CNI as K8S_POD_NAME
 	cniResults := make([]*cnitypes.Result, len(c.config.Networks))
 	for i, nw := range c.config.Networks {
 		cniRes, err := rootlessCNIInfraCallAlloc(infra, c.ID(), nw, k8sPodName)
@@ -115,12 +115,16 @@ func getRootlessCNIInfraLock(r *Runtime) (lockfile.Locker, error) {
 	return lockfile.GetLockfile(fname)
 }
 
-func getPodOrContainerName(c *Container) string {
-	pod, err := c.runtime.GetPod(c.PodID())
-	if err != nil || pod.config.Name == "" {
-		return c.Name()
+// getCNIPodName return the pod name (hostname) used by CNI and the dnsname plugin.
+// If we are in the pod network namespace use the pod name otherwise the container name
+func getCNIPodName(c *Container) string {
+	if c.config.NetMode.IsPod() || c.IsInfra() {
+		pod, err := c.runtime.GetPod(c.PodID())
+		if err == nil {
+			return pod.Name()
+		}
 	}
-	return pod.config.Name
+	return c.Name()
 }
 
 func rootlessCNIInfraCallAlloc(infra *Container, id, nw, k8sPodName string) (*cnitypes.Result, error) {

test/e2e/run_networking_test.go

@@ -594,4 +594,39 @@ var _ = Describe("Podman run networking", func() {
 		Expect(run.ExitCode()).To(BeZero())
 		Expect(strings.Contains(run.OutputToString(), hostname)).To(BeTrue())
 	})
+
+	It("podman run check dnsname plugin", func() {
+		pod := "testpod"
+		session := podmanTest.Podman([]string{"pod", "create", "--name", pod})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+
+		net := "dnsNetTest"
+		session = podmanTest.Podman([]string{"network", "create", net})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+		defer podmanTest.removeCNINetwork(net)
+
+		pod2 := "testpod2"
+		session = podmanTest.Podman([]string{"pod", "create", "--network", net, "--name", pod2})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+
+		session = podmanTest.Podman([]string{"run", "--name", "con1", "--network", net, ALPINE, "nslookup", "con1"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+
+		session = podmanTest.Podman([]string{"run", "--name", "con2", "--pod", pod, "--network", net, ALPINE, "nslookup", "con2"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+
+		session = podmanTest.Podman([]string{"run", "--name", "con3", "--pod", pod2, ALPINE, "nslookup", "con3"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(1))
+		Expect(session.ErrorToString()).To(ContainSubstring("can't resolve 'con3'"))
+
+		session = podmanTest.Podman([]string{"run", "--name", "con4", "--network", net, ALPINE, "nslookup", pod2})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(BeZero())
+	})
 })