Merge pull request #8497 from AlbanBedel/kube-volume

Add support for persistent volume claims in kube files 

1 files changed, 124 insertions, 0 deletions

diff --git a/pkg/specgen/generate/kube/volume.go b/pkg/specgen/generate/kube/volume.go
new file mode 100644
index 000000000..2ef0f4c23
--- /dev/null
+++ b/pkg/specgen/generate/kube/volume.go
@@ -0,0 +1,124 @@
+package kube
+
+import (
+	"os"
+
+	"github.com/containers/buildah/pkg/parse"
+	"github.com/containers/podman/v2/libpod"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	v1 "k8s.io/api/core/v1"
+)
+
+const (
+	// https://kubernetes.io/docs/concepts/storage/volumes/#hostpath
+	kubeDirectoryPermission = 0755
+	// https://kubernetes.io/docs/concepts/storage/volumes/#hostpath
+	kubeFilePermission = 0644
+)
+
+type KubeVolumeType int
+
+const (
+	KubeVolumeTypeBindMount KubeVolumeType = iota
+	KubeVolumeTypeNamed     KubeVolumeType = iota
+)
+
+type KubeVolume struct {
+	// Type of volume to create
+	Type KubeVolumeType
+	// Path for bind mount or volume name for named volume
+	Source string
+}
+
+// Create a KubeVolume from an HostPathVolumeSource
+func VolumeFromHostPath(hostPath *v1.HostPathVolumeSource) (*KubeVolume, error) {
+	if hostPath.Type != nil {
+		switch *hostPath.Type {
+		case v1.HostPathDirectoryOrCreate:
+			if _, err := os.Stat(hostPath.Path); os.IsNotExist(err) {
+				if err := os.Mkdir(hostPath.Path, kubeDirectoryPermission); err != nil {
+					return nil, err
+				}
+			}
+			// Label a newly created volume
+			if err := libpod.LabelVolumePath(hostPath.Path); err != nil {
+				return nil, errors.Wrapf(err, "error giving %s a label", hostPath.Path)
+			}
+		case v1.HostPathFileOrCreate:
+			if _, err := os.Stat(hostPath.Path); os.IsNotExist(err) {
+				f, err := os.OpenFile(hostPath.Path, os.O_RDONLY|os.O_CREATE, kubeFilePermission)
+				if err != nil {
+					return nil, errors.Wrap(err, "error creating HostPath")
+				}
+				if err := f.Close(); err != nil {
+					logrus.Warnf("Error in closing newly created HostPath file: %v", err)
+				}
+			}
+			// unconditionally label a newly created volume
+			if err := libpod.LabelVolumePath(hostPath.Path); err != nil {
+				return nil, errors.Wrapf(err, "error giving %s a label", hostPath.Path)
+			}
+		case v1.HostPathSocket:
+			st, err := os.Stat(hostPath.Path)
+			if err != nil {
+				return nil, errors.Wrap(err, "error checking HostPathSocket")
+			}
+			if st.Mode()&os.ModeSocket != os.ModeSocket {
+				return nil, errors.Errorf("error checking HostPathSocket: path %s is not a socket", hostPath.Path)
+			}
+
+		case v1.HostPathDirectory:
+		case v1.HostPathFile:
+		case v1.HostPathUnset:
+			// do nothing here because we will verify the path exists in validateVolumeHostDir
+			break
+		default:
+			return nil, errors.Errorf("Invalid HostPath type %v", hostPath.Type)
+		}
+	}
+
+	if err := parse.ValidateVolumeHostDir(hostPath.Path); err != nil {
+		return nil, errors.Wrapf(err, "error in parsing HostPath in YAML")
+	}
+
+	return &KubeVolume{
+		Type:   KubeVolumeTypeBindMount,
+		Source: hostPath.Path,
+	}, nil
+}
+
+// Create a KubeVolume from a PersistentVolumeClaimVolumeSource
+func VolumeFromPersistentVolumeClaim(claim *v1.PersistentVolumeClaimVolumeSource) (*KubeVolume, error) {
+	return &KubeVolume{
+		Type:   KubeVolumeTypeNamed,
+		Source: claim.ClaimName,
+	}, nil
+}
+
+// Create a KubeVolume from one of the supported VolumeSource
+func VolumeFromSource(volumeSource v1.VolumeSource) (*KubeVolume, error) {
+	if volumeSource.HostPath != nil {
+		return VolumeFromHostPath(volumeSource.HostPath)
+	} else if volumeSource.PersistentVolumeClaim != nil {
+		return VolumeFromPersistentVolumeClaim(volumeSource.PersistentVolumeClaim)
+	} else {
+		return nil, errors.Errorf("HostPath and PersistentVolumeClaim are currently the conly supported VolumeSource")
+	}
+}
+
+// Create a map of volume name to KubeVolume
+func InitializeVolumes(specVolumes []v1.Volume) (map[string]*KubeVolume, error) {
+	volumes := make(map[string]*KubeVolume)
+
+	for _, specVolume := range specVolumes {
+		volume, err := VolumeFromSource(specVolume.VolumeSource)
+		if err != nil {
+			return nil, err
+		}
+
+		volumes[specVolume.Name] = volume
+	}
+
+	return volumes, nil
+}