[niedbalski, r=freyes,billy-olsen] Fix fstab entry for loopback devices.

Closes-Bug: 1510666

charmhelpers/contrib/storage/linux/loopback.py

@@ -76,3 +76,13 @@ def ensure_loopback_device(path, size):
         check_call(cmd)
 
     return create_loopback(path)
+
+
+def is_mapped_loopback_device(device):
+    """
+    Checks if a given device name is an existing/mapped loopback device.
+    :param device: str: Full path to the device (eg, /dev/loop1).
+    :returns: str: Path to the backing file if is a loopback device
+    empty string otherwise
+    """
+    return loopback_devices().get(device, "")

lib/swift_storage_utils.py

@@ -27,6 +27,7 @@ from charmhelpers.fetch import (
 from charmhelpers.core.host import (
     mkdir,
     mount,
+    fstab_add,
     service_restart,
     lsb_release
 )
@@ -45,6 +46,10 @@ from charmhelpers.contrib.storage.linux.utils import (
     is_device_mounted,
 )
 
+from charmhelpers.contrib.storage.linux.loopback import (
+    is_mapped_loopback_device,
+)
+
 from charmhelpers.contrib.openstack.utils import (
     configure_installation_source,
     get_os_codename_install_source,
@@ -253,8 +258,20 @@ def setup_storage():
         _dev = os.path.basename(dev)
         _mp = os.path.join('/srv', 'node', _dev)
         mkdir(_mp, owner='swift', group='swift')
-        mount(dev, '/srv/node/%s' % _dev, persist=True,
+
-              filesystem="xfs")
+        options = None
+        loopback_device = is_mapped_loopback_device(dev)
+
+        if loopback_device:
+            dev = loopback_device
+            options = "loop, defaults"
+
+        mountpoint = '/srv/node/%s' % _dev
+        filesystem = "xfs"
+
+        mount(dev, mountpoint, filesystem=filesystem)
+        fstab_add(dev, mountpoint, filesystem, options=options)
+
     check_call(['chown', '-R', 'swift:swift', '/srv/node/'])
     check_call(['chmod', '-R', '0755', '/srv/node/'])
 

unit_tests/test_swift_storage_utils.py

@@ -28,6 +28,9 @@ TO_PATCH = [
     '_save_script_rc',
     'lsb_release',
     'is_paused',
+    'fstab_add',
+    'mount',
+    'is_mapped_loopback_device',
 ]
 
 
@@ -218,6 +221,7 @@ class SwiftStorageUtilsTests(CharmTestCase):
     @patch.object(swift_utils, 'mkfs_xfs')
     @patch.object(swift_utils, 'determine_block_devices')
     def test_setup_storage_overwrite(self, determine, mkfs, clean):
+        self.is_mapped_loopback_device.return_value = None
         determine.return_value = ['/dev/vdb']
         self.test_config.set('overwrite', 'True')
         swift_utils.setup_storage()
@@ -225,7 +229,10 @@ class SwiftStorageUtilsTests(CharmTestCase):
         self.mkdir.assert_called_with('/srv/node/vdb', owner='swift',
                                       group='swift')
         self.mount.assert_called_with('/dev/vdb', '/srv/node/vdb',
-                                      filesystem='xfs', persist=True)
+                                      filesystem='xfs')
+        self.fstab_add.assert_called_with('/dev/vdb', '/srv/node/vdb',
+                                          'xfs',
+                                          options=None)
         calls = [call(['chown', '-R', 'swift:swift', '/srv/node/']),
                  call(['chmod', '-R', '0755', '/srv/node/'])]
         self.check_call.assert_has_calls(calls)
@@ -338,3 +345,21 @@ class SwiftStorageUtilsTests(CharmTestCase):
                     swift_utils.OBJECT_SVCS)
         for service in services:
             self.assertIn(call(service), self.service_restart.call_args_list)
+
+    @patch.object(swift_utils, "mkfs_xfs")
+    @patch.object(swift_utils, "determine_block_devices")
+    def test_setup_storage_img(self, determine, mkfs):
+        determine.return_value = ["/srv/test.img", ]
+        self.is_mapped_loopback_device.return_value = "/srv/test.img"
+        swift_utils.setup_storage()
+        self.mount.assert_called_with(
+            "/srv/test.img",
+            "/srv/node/test.img",
+            filesystem="xfs",
+        )
+        self.fstab_add.assert_called_with(
+            '/srv/test.img',
+            '/srv/node/test.img',
+            'xfs',
+            options='loop, defaults'
+        )