Merge pull request #22575 from MikaelCluseau/wip-issue-20466

Automatic merge from submit-queue

Add subPath to mount a child dir or file of a volumeMount

Allow users to specify a subPath in Container.volumeMounts so they can use a single volume for many mounts instead of creating many volumes. For instance, a user can now use a single PersistentVolume to store the Mysql database and the document root of an Apache server of a LAMP stack pod by mapping them to different subPaths in this single volume.

Also solves https://github.com/kubernetes/kubernetes/issues/20466.

pkg/api/v1/deep_copy_generated.go

@@ -2916,6 +2916,7 @@ func DeepCopy_v1_VolumeMount(in VolumeMount, out *VolumeMount, c *conversion.Clo
 	out.Name = in.Name
 	out.ReadOnly = in.ReadOnly
 	out.MountPath = in.MountPath
+	out.SubPath = in.SubPath
 	return nil
 }