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.

api/swagger-spec/apps_v1alpha1.json

@@ -2031,6 +2031,10 @@
      "mountPath": {
       "type": "string",
       "description": "Path within the container at which the volume should be mounted.  Must not contain ':'."
+     },
+     "subPath": {
+      "type": "string",
+      "description": "Path within the volume from which the container's volume should be mounted. Defaults to \"\" (volume's root)."
      }
     }
    },

api/swagger-spec/batch_v1.json

@@ -2036,6 +2036,10 @@
      "mountPath": {
       "type": "string",
       "description": "Path within the container at which the volume should be mounted.  Must not contain ':'."
+     },
+     "subPath": {
+      "type": "string",
+      "description": "Path within the volume from which the container's volume should be mounted. Defaults to \"\" (volume's root)."
      }
     }
    },

api/swagger-spec/extensions_v1beta1.json

@@ -7343,6 +7343,10 @@
      "mountPath": {
       "type": "string",
       "description": "Path within the container at which the volume should be mounted.  Must not contain ':'."
+     },
+     "subPath": {
+      "type": "string",
+      "description": "Path within the volume from which the container's volume should be mounted. Defaults to \"\" (volume's root)."
      }
     }
    },

api/swagger-spec/v1.json

@@ -17330,6 +17330,10 @@
      "mountPath": {
       "type": "string",
       "description": "Path within the container at which the volume should be mounted.  Must not contain ':'."
+     },
+     "subPath": {
+      "type": "string",
+      "description": "Path within the volume from which the container's volume should be mounted. Defaults to \"\" (volume's root)."
      }
     }
    },