Merge pull request #15473 from umohnani8/empty-dir

Add emptyDir volume support to kube play

docs/source/markdown/podman-kube-play.1.md.in

@@ -21,7 +21,7 @@ Currently, the supported Kubernetes kinds are:
 
 `Kubernetes Pods or Deployments`
 
-Only two volume types are supported by kube play, the *hostPath* and *persistentVolumeClaim* volume types. For the *hostPath* volume type, only the  *default (empty)*, *DirectoryOrCreate*, *Directory*, *FileOrCreate*, *File*, *Socket*, *CharDevice* and *BlockDevice* subtypes are supported. Podman interprets the value of *hostPath* *path* as a file path when it contains at least one forward slash, otherwise Podman treats the value as the name of a named volume. When using a *persistentVolumeClaim*, the value for *claimName* is the name for the Podman named volume.
+Only three volume types are supported by kube play, the *hostPath*, *emptyDir*, and *persistentVolumeClaim* volume types. For the *hostPath* volume type, only the  *default (empty)*, *DirectoryOrCreate*, *Directory*, *FileOrCreate*, *File*, *Socket*, *CharDevice* and *BlockDevice* subtypes are supported. Podman interprets the value of *hostPath* *path* as a file path when it contains at least one forward slash, otherwise Podman treats the value as the name of a named volume. When using a *persistentVolumeClaim*, the value for *claimName* is the name for the Podman named volume. When using an *emptyDir* volume, podman creates an anonymous volume that is attached the containers running inside the pod and is deleted once the pod is removed.
 
 Note: When playing a kube YAML with init containers, the init container will be created with init type value `once`. To change the default type, use the `io.podman.annotations.init.container.type` annotation to set the type to `always`.
 

libpod/container.go

@@ -237,6 +237,9 @@ type ContainerNamedVolume struct {
 	Dest string `json:"dest"`
 	// Options are fstab style mount options
 	Options []string `json:"options,omitempty"`
+	// IsAnonymous sets the named volume as anonymous even if it has a name
+	// This is used for emptyDir volumes from a kube yaml
+	IsAnonymous bool `json:"setAnonymous,omitempty"`
 }
 
 // ContainerOverlayVolume is a overlay volume that will be mounted into the

libpod/options.go

@@ -1416,6 +1416,7 @@ func WithNamedVolumes(volumes []*ContainerNamedVolume) CtrCreateOption {
 				Name:        vol.Name,
 				Dest:        vol.Dest,
 				Options:     mountOpts,
+				IsAnonymous: vol.IsAnonymous,
 			})
 		}
 

libpod/runtime_ctr.go

@@ -474,6 +474,11 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 				return nil, fmt.Errorf("error retrieving named volume %s for new container: %w", vol.Name, err)
 			}
 		}
+		if vol.IsAnonymous {
+			// If SetAnonymous is true, make this an anonymous volume
+			// this is needed for emptyDir volumes from kube yamls
+			isAnonymous = true
+		}
 
 		logrus.Debugf("Creating new volume %s for container", vol.Name)
 
@@ -814,11 +819,11 @@ func (r *Runtime) removeContainer(ctx context.Context, c *Container, force, remo
 					// Ignore error, since podman will report original error
 					volumesFrom, _ := c.volumesFrom()
 					if len(volumesFrom) > 0 {
-						logrus.Debugf("Cleaning up volume not possible since volume is in use (%s)", v)
+						logrus.Debugf("Cleaning up volume not possible since volume is in use (%s)", v.Name)
 						continue
 					}
 				}
-				logrus.Errorf("Cleaning up volume (%s): %v", v, err)
+				logrus.Errorf("Cleaning up volume (%s): %v", v.Name, err)
 			}
 		}
 	}
@@ -968,7 +973,7 @@ func (r *Runtime) evictContainer(ctx context.Context, idOrName string, removeVol
 				continue
 			}
 			if err := r.removeVolume(ctx, volume, false, timeout, false); err != nil && err != define.ErrNoSuchVolume && err != define.ErrVolumeBeingUsed {
-				logrus.Errorf("Cleaning up volume (%s): %v", v, err)
+				logrus.Errorf("Cleaning up volume (%s): %v", v.Name, err)
 			}
 		}
 	}

pkg/domain/infra/abi/play.go

@@ -436,7 +436,7 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 	}
 
 	// Go through the volumes and create a podman volume for all volumes that have been
-	// defined by a configmap
+	// defined by a configmap or secret
 	for _, v := range volumes {
 		if (v.Type == kube.KubeVolumeTypeConfigMap || v.Type == kube.KubeVolumeTypeSecret) && !v.Optional {
 			vol, err := ic.Libpod.NewVolume(ctx, libpod.WithVolumeName(v.Source))

pkg/k8s.io/api/core/v1/types.go

@@ -58,6 +58,10 @@ type VolumeSource struct {
 	ConfigMap *ConfigMapVolumeSource `json:"configMap,omitempty"`
 	// Secret represents a secret that should be mounted as a volume
 	Secret *SecretVolumeSource `json:"secret,omitempty"`
+	// emptyDir represents a temporary directory that shares a pod's lifetime.
+	// More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir
+	// +optional
+	EmptyDir *EmptyDirVolumeSource `json:"emptyDir,omitempty"`
 }
 
 // PersistentVolumeClaimVolumeSource references the user's PVC in the same namespace.

pkg/specgen/generate/container_create.go

@@ -390,6 +390,7 @@ func createContainerOptions(rt *libpod.Runtime, s *specgen.SpecGenerator, pod *l
 				Name:        v.Name,
 				Dest:        v.Dest,
 				Options:     v.Options,
+				IsAnonymous: v.IsAnonymous,
 			})
 		}
 		options = append(options, libpod.WithNamedVolumes(vols))

pkg/specgen/generate/kube/kube.go

@@ -406,8 +406,15 @@ func ToSpecGen(ctx context.Context, opts *CtrSpecGenOptions) (*specgen.SpecGener
 				Name:    volumeSource.Source,
 				Options: options,
 			}
-
 			s.Volumes = append(s.Volumes, &secretVolume)
+		case KubeVolumeTypeEmptyDir:
+			emptyDirVolume := specgen.NamedVolume{
+				Dest:        volume.MountPath,
+				Name:        volumeSource.Source,
+				Options:     options,
+				IsAnonymous: true,
+			}
+			s.Volumes = append(s.Volumes, &emptyDirVolume)
 		default:
 			return nil, errors.New("unsupported volume source type")
 		}

pkg/specgen/generate/kube/volume.go

@@ -32,6 +32,7 @@ const (
 	KubeVolumeTypeBlockDevice
 	KubeVolumeTypeCharDevice
 	KubeVolumeTypeSecret
+	KubeVolumeTypeEmptyDir
 )
 
 //nolint:revive
@@ -219,8 +220,13 @@ func VolumeFromConfigMap(configMapVolumeSource *v1.ConfigMapVolumeSource, config
 	return kv, nil
 }
 
+// Create a kubeVolume for an emptyDir volume
+func VolumeFromEmptyDir(emptyDirVolumeSource *v1.EmptyDirVolumeSource, name string) (*KubeVolume, error) {
+	return &KubeVolume{Type: KubeVolumeTypeEmptyDir, Source: name}, nil
+}
+
 // Create a KubeVolume from one of the supported VolumeSource
-func VolumeFromSource(volumeSource v1.VolumeSource, configMaps []v1.ConfigMap, secretsManager *secrets.SecretsManager) (*KubeVolume, error) {
+func VolumeFromSource(volumeSource v1.VolumeSource, configMaps []v1.ConfigMap, secretsManager *secrets.SecretsManager, volName string) (*KubeVolume, error) {
 	switch {
 	case volumeSource.HostPath != nil:
 		return VolumeFromHostPath(volumeSource.HostPath)
@@ -230,8 +236,10 @@ func VolumeFromSource(volumeSource v1.VolumeSource, configMaps []v1.ConfigMap, s
 		return VolumeFromConfigMap(volumeSource.ConfigMap, configMaps)
 	case volumeSource.Secret != nil:
 		return VolumeFromSecret(volumeSource.Secret, secretsManager)
+	case volumeSource.EmptyDir != nil:
+		return VolumeFromEmptyDir(volumeSource.EmptyDir, volName)
 	default:
-		return nil, errors.New("HostPath, ConfigMap, and PersistentVolumeClaim are currently the only supported VolumeSource")
+		return nil, errors.New("HostPath, ConfigMap, EmptyDir, and PersistentVolumeClaim are currently the only supported VolumeSource")
 	}
 }
 
@@ -240,7 +248,7 @@ func InitializeVolumes(specVolumes []v1.Volume, configMaps []v1.ConfigMap, secre
 	volumes := make(map[string]*KubeVolume)
 
 	for _, specVolume := range specVolumes {
-		volume, err := VolumeFromSource(specVolume.VolumeSource, configMaps, secretsManager)
+		volume, err := VolumeFromSource(specVolume.VolumeSource, configMaps, secretsManager, specVolume.Name)
 		if err != nil {
 			return nil, fmt.Errorf("failed to create volume %q: %w", specVolume.Name, err)
 		}

pkg/specgen/volumes.go

@@ -23,6 +23,9 @@ type NamedVolume struct {
 	Dest string
 	// Options are options that the named volume will be mounted with.
 	Options []string
+	// IsAnonymous sets the named volume as anonymous even if it has a name
+	// This is used for emptyDir volumes from a kube yaml
+	IsAnonymous bool
 }
 
 // OverlayVolume holds information about a overlay volume that will be mounted into

test/e2e/play_kube_test.go

@@ -509,6 +509,9 @@ spec:
   volumes:
   {{ range . }}
   - name: {{ .Name }}
+    {{- if (eq .VolumeType "EmptyDir") }}
+    emptyDir: {}
+    {{- end }}
     {{- if (eq .VolumeType "HostPath") }}
     hostPath:
       path: {{ .HostPath.Path }}
@@ -1242,12 +1245,15 @@ type ConfigMap struct {
 	Optional bool
 }
 
+type EmptyDir struct{}
+
 type Volume struct {
 	VolumeType string
 	Name       string
 	HostPath
 	PersistentVolumeClaim
 	ConfigMap
+	EmptyDir
 }
 
 // getHostPathVolume takes a type and a location for a HostPath
@@ -1289,6 +1295,14 @@ func getConfigMapVolume(vName string, items []map[string]string, optional bool)
 	}
 }
 
+func getEmptyDirVolume() *Volume {
+	return &Volume{
+		VolumeType: "EmptyDir",
+		Name:       defaultVolName,
+		EmptyDir:   EmptyDir{},
+	}
+}
+
 type Env struct {
 	Name      string
 	Value     string
@@ -2762,6 +2776,43 @@ VOLUME %s`, ALPINE, hostPathDir+"/")
 		Expect(kube).Should(Exit(0))
 	})
 
+	It("podman play kube with emptyDir volume", func() {
+		podName := "test-pod"
+		ctrName1 := "vol-test-ctr"
+		ctrName2 := "vol-test-ctr-2"
+		ctr1 := getCtr(withVolumeMount("/test-emptydir", false), withImage(BB), withName(ctrName1))
+		ctr2 := getCtr(withVolumeMount("/test-emptydir-2", false), withImage(BB), withName(ctrName2))
+		pod := getPod(withPodName(podName), withVolume(getEmptyDirVolume()), withCtr(ctr1), withCtr(ctr2))
+		err = generateKubeYaml("pod", pod, kubeYaml)
+		Expect(err).To(BeNil())
+
+		kube := podmanTest.Podman([]string{"play", "kube", kubeYaml})
+		kube.WaitWithDefaultTimeout()
+		Expect(kube).Should(Exit(0))
+
+		emptyDirCheck1 := podmanTest.Podman([]string{"exec", podName + "-" + ctrName1, "ls", "/test-emptydir"})
+		emptyDirCheck1.WaitWithDefaultTimeout()
+		Expect(emptyDirCheck1).Should(Exit(0))
+
+		emptyDirCheck2 := podmanTest.Podman([]string{"exec", podName + "-" + ctrName2, "ls", "/test-emptydir-2"})
+		emptyDirCheck2.WaitWithDefaultTimeout()
+		Expect(emptyDirCheck2).Should(Exit(0))
+
+		volList1 := podmanTest.Podman([]string{"volume", "ls", "-q"})
+		volList1.WaitWithDefaultTimeout()
+		Expect(volList1).Should(Exit(0))
+		Expect(volList1.OutputToString()).To(Equal(defaultVolName))
+
+		remove := podmanTest.Podman([]string{"pod", "rm", "-f", podName})
+		remove.WaitWithDefaultTimeout()
+		Expect(remove).Should(Exit(0))
+
+		volList2 := podmanTest.Podman([]string{"volume", "ls", "-q"})
+		volList2.WaitWithDefaultTimeout()
+		Expect(volList2).Should(Exit(0))
+		Expect(volList2.OutputToString()).To(Equal(""))
+	})
+
 	It("podman play kube applies labels to pods", func() {
 		var numReplicas int32 = 5
 		expectedLabelKey := "key1"