add --lvsize option to atomic storage modify

Signed-off-by: Shishir Mahajan <shishir.mahajan@redhat.com>

Closes: #900
Approved by: rhatdan

Atomic/storage.py

@@ -66,6 +66,7 @@ def cli(subparser):
     modifyp.add_argument('--rootfs', dest="rootfs", default=None,
                          help='Mountpath where logical volume for container storage would be mounted. e.g. /var/lib/containers')
     modifyp.add_argument('--lvname', dest="lvname", default=None, help='logical volume name for container storage. e.g container-root-lv')
+    modifyp.add_argument('--lvsize', dest="lvsize", default=None, help='logical volume size for container storage.')
     modifyp.add_argument('--driver', dest="driver", default=None, help='The storage backend driver', choices=['devicemapper', 'overlay', 'overlay2'])
     modifyp.add_argument('--vgroup', dest="vgroup", default=None, help='The storage volume group')
     modifyp.add_argument("--graph", dest="graph",
@@ -172,6 +173,13 @@ class Storage(Atomic):
             if self.args.driver:
                 self._driver(self.args.driver)
             if self.args.rootfs and self.args.lvname:
+                if self.args.lvsize:
+                    try:
+                        cmd = 'bash -c ". /usr/lib/docker-storage-setup/libdss.sh; check_data_size_syntax {0}"'.format(self.args.lvsize)
+                        util.check_call(cmd)
+                    except subprocess.CalledProcessError:
+                        raise ValueError("Invalid format for --lvsize")
+                    self._lvsize(self.args.lvsize)
                 self._rootfs(self.args.rootfs)
                 self._lvname(self.args.lvname)
             else:
@@ -254,6 +262,9 @@ class Storage(Atomic):
     def _lvname(self, lvname):
         util.sh_modify_var_in_file(self.dss_conf, "CONTAINER_ROOT_LV_NAME",
                                    lambda old: lvname)
+    def _lvsize(self, lvsize):
+        util.sh_modify_var_in_file(self.dss_conf, "CONTAINER_ROOT_LV_SIZE",
+                                   lambda old: lvsize)
 
     def _vgroup(self, vgroup):
         util.sh_modify_var_in_file(self.dss_conf, "VG",

bash/atomic

@@ -1289,6 +1289,7 @@ _atomic_storage_modify() {
 		--add-device
 		--rootfs
 		--lvname
+		--lvsize
 	"
 	local all_options="$options_with_args
 		--help

docs/atomic-storage.1.md

@@ -98,6 +98,16 @@ E.g. --rootfs="/var/lib/containers". This will mount "container-root-lv"
 on "/var/lib/containers".
 Note: You must set --lvname when setting --rootfs.
 
+**--lvsize**
+Logical volume size for container storage.
+E.g. --lvsize="20%FREE". It defaults to 40% of all free space.
+--lvsize can take values acceptable to "lvcreate -L" as well
+as some values acceptable to "lvcreate -l". If user intends to pass
+values acceptable to "lvcreate -l", then only those values which
+contains "%" in syntax are acceptable.  If value does not contain
+"%" it is assumed value is suitable for "lvcreate -L".
+Note: You must set --lvname and --rootfs when setting --lvsize.
+
 **--vgroup**
 The name of the volume group for the storage pool.