Make nfs version for nova ephemeral storage configurable

New parameter ``NovaNfsVersion`` allow configuring the NFS version
used for nova storage (when NovaNfsEnabled is true). Since NFSv3
does not support full locking a NFSv4 version need to be used. To
not break current installations the default is the previous hard
coded version 4.

Change-Id: I810478ed82ee6dc056d9652be91dc45b123e78cf

deployment/nova/nova-compute-container-puppet.yaml

@@ -97,6 +97,16 @@ parameters:
     default: 'context=system_u:object_r:nfs_t:s0'
     description: NFS mount options for nova storage (when NovaNfsEnabled is true)
     type: string
+  NovaNfsVersion:
+    default: '4'
+    description: >
+      NFS version used for nova storage (when NovaNfsEnabled is true). Since
+      NFSv3 does not support full locking a NFSv4 version need to be used.
+      To not break current installations the default is the previous hard
+      coded version 4.
+    type: string
+    constraints:
+      - allowed_pattern: "^4.?[0-9]?"
   CinderEnableRbdBackend:
     default: false
     description: Whether to enable or not the Rbd backend for Cinder
@@ -582,7 +592,8 @@ outputs:
               nfs_backend_enable: {get_param: NovaNfsEnabled}
               nfs_share: {get_param: NovaNfsShare}
               nfs_options: {get_param: NovaNfsOptions}
-            mount: name=/var/lib/nova/instances src="{{nfs_share}}" fstype=nfs4 opts="_netdev,bg,{{nfs_options}},vers=4,nfsvers=4" state=mounted
+              nfs_vers: {get_param: NovaNfsVersion}
+            mount: name=/var/lib/nova/instances src="{{nfs_share}}" fstype=nfs4 opts="_netdev,bg,{{nfs_options}},vers={{nfs_vers}},nfsvers={{nfs_vers}}" state=mounted
             when: nfs_backend_enable|bool
           - name: is Nova Resume Guests State On Host Boot enabled
             set_fact:

environments/storage-environment.yaml

@@ -60,6 +60,8 @@ parameter_defaults:
   # NovaNfsShare: ''
   ## Mount options for the NFS instance file storage mount point
   # NovaNfsOptions: 'context=system_u:object_r:nfs_t:s0'
+  ## NFS version to be used to mount the NovaNfsShare. Default 4
+  # NovaNfsVersion: '4.2'
 
 
   #### CEPH SETTINGS ####

releasenotes/notes/nova_add_nfs_vers_parameter-62b9e9d6150358d1.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    New parameter ``NovaNfsVersion`` allow configuring the NFS version
+    used for nova storage (when NovaNfsEnabled is true). Since NFSv3
+    does not support full locking a NFSv4 version need to be used. To
+    not break current installations the default is the previous hard
+    coded version 4.

sample-env-generator/storage.yaml

@@ -50,8 +50,10 @@ environments:
           - NovaNfsEnabled
           - NovaNfsShare
           - NovaNfsOptions
+          - NovaNfsVersion
     sample_values:
       NovaNfsEnabled: True
+      NovaNfsVersion: '4.2'
     static:
       - NovaNfsEnabled
     description: |