Merge pull request #9150 from baude/playkubedns

Honor custom DNS in play|generate kube

libpod/kube.go

@@ -171,9 +171,10 @@ func (p *Pod) podWithContainers(containers []*Container, ports []v1.ContainerPor
 	deDupPodVolumes := make(map[string]*v1.Volume)
 	first := true
 	podContainers := make([]v1.Container, 0, len(containers))
+	dnsInfo := v1.PodDNSConfig{}
 	for _, ctr := range containers {
 		if !ctr.IsInfra() {
-			ctr, volumes, err := containerToV1Container(ctr)
+			ctr, volumes, _, err := containerToV1Container(ctr)
 			if err != nil {
 				return nil, err
 			}
@@ -196,6 +197,22 @@ func (p *Pod) podWithContainers(containers []*Container, ports []v1.ContainerPor
 				vol := vol
 				deDupPodVolumes[vol.Name] = &vol
 			}
+		} else {
+			_, _, infraDNS, err := containerToV1Container(ctr)
+			if err != nil {
+				return nil, err
+			}
+			if infraDNS != nil {
+				if servers := infraDNS.Nameservers; len(servers) > 0 {
+					dnsInfo.Nameservers = servers
+				}
+				if searches := infraDNS.Searches; len(searches) > 0 {
+					dnsInfo.Searches = searches
+				}
+				if options := infraDNS.Options; len(options) > 0 {
+					dnsInfo.Options = options
+				}
+			}
 		}
 	}
 	podVolumes := make([]v1.Volume, 0, len(deDupPodVolumes))
@@ -203,10 +220,10 @@ func (p *Pod) podWithContainers(containers []*Container, ports []v1.ContainerPor
 		podVolumes = append(podVolumes, *vol)
 	}
 
-	return addContainersAndVolumesToPodObject(podContainers, podVolumes, p.Name()), nil
+	return addContainersAndVolumesToPodObject(podContainers, podVolumes, p.Name(), &dnsInfo), nil
 }
 
-func addContainersAndVolumesToPodObject(containers []v1.Container, volumes []v1.Volume, podName string) *v1.Pod {
+func addContainersAndVolumesToPodObject(containers []v1.Container, volumes []v1.Volume, podName string, dnsOptions *v1.PodDNSConfig) *v1.Pod {
 	tm := v12.TypeMeta{
 		Kind:       "Pod",
 		APIVersion: "v1",
@@ -228,6 +245,9 @@ func addContainersAndVolumesToPodObject(containers []v1.Container, volumes []v1.
 		Containers: containers,
 		Volumes:    volumes,
 	}
+	if dnsOptions != nil {
+		ps.DNSConfig = dnsOptions
+	}
 	p := v1.Pod{
 		TypeMeta:   tm,
 		ObjectMeta: om,
@@ -241,32 +261,65 @@ func addContainersAndVolumesToPodObject(containers []v1.Container, volumes []v1.
 func simplePodWithV1Containers(ctrs []*Container) (*v1.Pod, error) {
 	kubeCtrs := make([]v1.Container, 0, len(ctrs))
 	kubeVolumes := make([]v1.Volume, 0)
+	podDNS := v1.PodDNSConfig{}
 	for _, ctr := range ctrs {
-		kubeCtr, kubeVols, err := containerToV1Container(ctr)
+		kubeCtr, kubeVols, ctrDNS, err := containerToV1Container(ctr)
 		if err != nil {
 			return nil, err
 		}
 		kubeCtrs = append(kubeCtrs, kubeCtr)
 		kubeVolumes = append(kubeVolumes, kubeVols...)
-	}
-	return addContainersAndVolumesToPodObject(kubeCtrs, kubeVolumes, strings.ReplaceAll(ctrs[0].Name(), "_", "")), nil
 
+		// Combine DNS information in sum'd structure
+		if ctrDNS != nil {
+			// nameservers
+			if servers := ctrDNS.Nameservers; servers != nil {
+				if podDNS.Nameservers == nil {
+					podDNS.Nameservers = make([]string, 0)
+				}
+				for _, s := range servers {
+					if !util.StringInSlice(s, podDNS.Nameservers) { // only append if it does not exist
+						podDNS.Nameservers = append(podDNS.Nameservers, s)
+					}
+				}
+			}
+			// search domains
+			if domains := ctrDNS.Searches; domains != nil {
+				if podDNS.Searches == nil {
+					podDNS.Searches = make([]string, 0)
+				}
+				for _, d := range domains {
+					if !util.StringInSlice(d, podDNS.Searches) { // only append if it does not exist
+						podDNS.Searches = append(podDNS.Searches, d)
+					}
+				}
+			}
+			// dns options
+			if options := ctrDNS.Options; options != nil {
+				if podDNS.Options == nil {
+					podDNS.Options = make([]v1.PodDNSConfigOption, 0)
+				}
+				podDNS.Options = append(podDNS.Options, options...)
+			}
+		} // end if ctrDNS
+	}
+	return addContainersAndVolumesToPodObject(kubeCtrs, kubeVolumes, strings.ReplaceAll(ctrs[0].Name(), "_", ""), &podDNS), nil
 }
 
 // containerToV1Container converts information we know about a libpod container
 // to a V1.Container specification.
-func containerToV1Container(c *Container) (v1.Container, []v1.Volume, error) {
+func containerToV1Container(c *Container) (v1.Container, []v1.Volume, *v1.PodDNSConfig, error) {
 	kubeContainer := v1.Container{}
 	kubeVolumes := []v1.Volume{}
 	kubeSec, err := generateKubeSecurityContext(c)
 	if err != nil {
-		return kubeContainer, kubeVolumes, err
+		return kubeContainer, kubeVolumes, nil, err
 	}
 
 	if len(c.config.Spec.Linux.Devices) > 0 {
 		// TODO Enable when we can support devices and their names
 		kubeContainer.VolumeDevices = generateKubeVolumeDeviceFromLinuxDevice(c.Spec().Linux.Devices)
-		return kubeContainer, kubeVolumes, errors.Wrapf(define.ErrNotImplemented, "linux devices")
+		return kubeContainer, kubeVolumes, nil, errors.Wrapf(define.ErrNotImplemented, "linux devices")
 	}
 
 	if len(c.config.UserVolumes) > 0 {
@@ -274,7 +327,7 @@ func containerToV1Container(c *Container) (v1.Container, []v1.Volume, error) {
 		// Volume names need to be coordinated "globally" in the kube files.
 		volumeMounts, volumes, err := libpodMountsToKubeVolumeMounts(c)
 		if err != nil {
-			return kubeContainer, kubeVolumes, err
+			return kubeContainer, kubeVolumes, nil, err
 		}
 		kubeContainer.VolumeMounts = volumeMounts
 		kubeVolumes = append(kubeVolumes, volumes...)
@@ -282,16 +335,16 @@ func containerToV1Container(c *Container) (v1.Container, []v1.Volume, error) {
 
 	envVariables, err := libpodEnvVarsToKubeEnvVars(c.config.Spec.Process.Env)
 	if err != nil {
-		return kubeContainer, kubeVolumes, err
+		return kubeContainer, kubeVolumes, nil, err
 	}
 
 	portmappings, err := c.PortMappings()
 	if err != nil {
-		return kubeContainer, kubeVolumes, err
+		return kubeContainer, kubeVolumes, nil, err
 	}
 	ports, err := ocicniPortMappingToContainerPort(portmappings)
 	if err != nil {
-		return kubeContainer, kubeVolumes, err
+		return kubeContainer, kubeVolumes, nil, err
 	}
 
 	containerCommands := c.Command()
@@ -355,7 +408,38 @@ func containerToV1Container(c *Container) (v1.Container, []v1.Volume, error) {
 		}
 	}
 
-	return kubeContainer, kubeVolumes, nil
+	// Obtain the DNS entries from the container
+	dns := v1.PodDNSConfig{}
+
+	// DNS servers
+	if servers := c.config.DNSServer; len(servers) > 0 {
+		dnsServers := make([]string, 0)
+		for _, server := range servers {
+			dnsServers = append(dnsServers, server.String())
+		}
+		dns.Nameservers = dnsServers
+	}
+
+	// DNS search domains
+	if searches := c.config.DNSSearch; len(searches) > 0 {
+		dns.Searches = searches
+	}
+
+	// DNS options
+	if options := c.config.DNSOption; len(options) > 0 {
+		dnsOptions := make([]v1.PodDNSConfigOption, 0)
+		for _, option := range options {
+			// the option can be "k:v" or just "k", no delimiter is required
+			opts := strings.SplitN(option, ":", 2)
+			dnsOpt := v1.PodDNSConfigOption{
+				Name:  opts[0],
+				Value: &opts[1],
+			}
+			dnsOptions = append(dnsOptions, dnsOpt)
+		}
+		dns.Options = dnsOptions
+	}
+	return kubeContainer, kubeVolumes, &dns, nil
 }
 
 // ocicniPortMappingToContainerPort takes an ocicni portmapping and converts

pkg/specgen/generate/kube/kube.go

@@ -3,6 +3,7 @@ package kube
 import (
 	"context"
 	"fmt"
+	"net"
 	"strings"
 
 	"github.com/containers/common/pkg/parse"
@@ -44,6 +45,31 @@ func ToPodGen(ctx context.Context, podName string, podYAML *v1.PodTemplateSpec)
 	podPorts := getPodPorts(podYAML.Spec.Containers)
 	p.PortMappings = podPorts
 
+	if dnsConfig := podYAML.Spec.DNSConfig; dnsConfig != nil {
+		// name servers
+		if dnsServers := dnsConfig.Nameservers; len(dnsServers) > 0 {
+			servers := make([]net.IP, 0)
+			for _, server := range dnsServers {
+				servers = append(servers, net.ParseIP(server))
+			}
+			p.DNSServer = servers
+		}
+		// search domans
+		if domains := dnsConfig.Searches; len(domains) > 0 {
+			p.DNSSearch = domains
+		}
+		// dns options
+		if options := dnsConfig.Options; len(options) > 0 {
+			dnsOptions := make([]string, 0)
+			for _, opts := range options {
+				d := opts.Name
+				if opts.Value != nil {
+					d += ":" + *opts.Value
+				}
+				dnsOptions = append(dnsOptions, d)
+			}
+		}
+	}
 	return p, nil
 }
 

test/e2e/generate_kube_test.go

@@ -540,4 +540,67 @@ var _ = Describe("Podman generate kube", func() {
 		kube.WaitWithDefaultTimeout()
 		Expect(kube.ExitCode()).ToNot(Equal(0))
 	})
+
+	It("podman generate kube on a container with dns options", func() {
+		top := podmanTest.Podman([]string{"run", "-dt", "--name", "top", "--dns", "8.8.8.8", "--dns-search", "foobar.com", "--dns-opt", "color:blue", ALPINE, "top"})
+		top.WaitWithDefaultTimeout()
+		Expect(top.ExitCode()).To(BeZero())
+
+		kube := podmanTest.Podman([]string{"generate", "kube", "top"})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube.ExitCode()).To(Equal(0))
+
+		pod := new(v1.Pod)
+		err := yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+
+		Expect(StringInSlice("8.8.8.8", pod.Spec.DNSConfig.Nameservers)).To(BeTrue())
+		Expect(StringInSlice("foobar.com", pod.Spec.DNSConfig.Searches)).To(BeTrue())
+		Expect(len(pod.Spec.DNSConfig.Options)).To(BeNumerically(">", 0))
+		Expect(pod.Spec.DNSConfig.Options[0].Name).To(Equal("color"))
+		Expect(*pod.Spec.DNSConfig.Options[0].Value).To(Equal("blue"))
+	})
+
+	It("podman generate kube multiple contianer dns servers and options are cumulative", func() {
+		top1 := podmanTest.Podman([]string{"run", "-dt", "--name", "top1", "--dns", "8.8.8.8", "--dns-search", "foobar.com", ALPINE, "top"})
+		top1.WaitWithDefaultTimeout()
+		Expect(top1.ExitCode()).To(BeZero())
+
+		top2 := podmanTest.Podman([]string{"run", "-dt", "--name", "top2", "--dns", "8.7.7.7", "--dns-search", "homer.com", ALPINE, "top"})
+		top2.WaitWithDefaultTimeout()
+		Expect(top2.ExitCode()).To(BeZero())
+
+		kube := podmanTest.Podman([]string{"generate", "kube", "top1", "top2"})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube.ExitCode()).To(Equal(0))
+
+		pod := new(v1.Pod)
+		err := yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+
+		Expect(StringInSlice("8.8.8.8", pod.Spec.DNSConfig.Nameservers)).To(BeTrue())
+		Expect(StringInSlice("8.7.7.7", pod.Spec.DNSConfig.Nameservers)).To(BeTrue())
+		Expect(StringInSlice("foobar.com", pod.Spec.DNSConfig.Searches)).To(BeTrue())
+		Expect(StringInSlice("homer.com", pod.Spec.DNSConfig.Searches)).To(BeTrue())
+	})
+
+	It("podman generate kube on a pod with dns options", func() {
+		top := podmanTest.Podman([]string{"run", "--pod", "new:pod1", "-dt", "--name", "top", "--dns", "8.8.8.8", "--dns-search", "foobar.com", "--dns-opt", "color:blue", ALPINE, "top"})
+		top.WaitWithDefaultTimeout()
+		Expect(top.ExitCode()).To(BeZero())
+
+		kube := podmanTest.Podman([]string{"generate", "kube", "pod1"})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube.ExitCode()).To(Equal(0))
+
+		pod := new(v1.Pod)
+		err := yaml.Unmarshal(kube.Out.Contents(), pod)
+		Expect(err).To(BeNil())
+
+		Expect(StringInSlice("8.8.8.8", pod.Spec.DNSConfig.Nameservers)).To(BeTrue())
+		Expect(StringInSlice("foobar.com", pod.Spec.DNSConfig.Searches)).To(BeTrue())
+		Expect(len(pod.Spec.DNSConfig.Options)).To(BeNumerically(">", 0))
+		Expect(pod.Spec.DNSConfig.Options[0].Name).To(Equal("color"))
+		Expect(*pod.Spec.DNSConfig.Options[0].Value).To(Equal("blue"))
+	})
 })