Skip osd-devices not absolute paths

This change skips over any devices which does not start with a leading
folder separator ('/'). Allowing such entries causes an OSD to be
created out of the charm directory. This can be caused by something as
innocuous as 2 spaces between devices. The result is that the root
device is also running an OSD, which is undesirable.

Change-Id: I5b52096da0b6f100ae9835c339905585425b27ae
Closes-Bug: 1652175

actions/add_disk.py

@@ -59,9 +59,13 @@ def add_device(request, device_path, bucket=None):
 
 
 def get_devices():
-    return [
+    devices = []
-        os.path.realpath(path)
+    for path in action_get('osd-devices').split(' '):
-        for path in action_get('osd-devices').split(' ')]
+        path = path.strip()
+        if os.path.isabs(path):
+            devices.append(path)
+
+    return devices
 
 
 if __name__ == "__main__":

hooks/ceph_hooks.py

@@ -365,12 +365,17 @@ def reformat_osd():
 
 
 def get_devices():
+    devices = []
+
     if config('osd-devices'):
-        devices = [
+        for path in config('osd-devices').split(' '):
-            os.path.realpath(path)
+            path = path.strip()
-            for path in config('osd-devices').split(' ')]
+            # Make sure its a device which is specified using an
-    else:
+            # absolute path so that the current working directory
-        devices = []
+            # or any relative path under this directory is not used
+            if os.path.isabs(path):
+                devices.append(os.path.realpath(path))
+
     # List storage instances for the 'osd-devices'
     # store declared for this charm too, and add
     # their block device paths to the list.

unit_tests/test_config.py

@@ -72,6 +72,25 @@ class GetDevicesTestCase(test_utils.CharmTestCase):
         self.test_config.set("osd-devices", "{} {}".format(device1, device2))
         self.assertEqual([device1, device2], hooks.get_devices())
 
+    def test_get_devices_extra_spaces(self):
+        """
+        Multiple spaces do not result in additional devices.
+        """
+        device1 = os.path.join(self.tmp_dir, "device1")
+        device2 = os.path.join(self.tmp_dir, "device2")
+        self.test_config.set("osd-devices", "{}  {}".format(device1, device2))
+        self.assertEqual([device1, device2], hooks.get_devices())
+
+    def test_get_devices_non_absolute_path(self):
+        """
+        Charm does not allow relative paths as this may result in a path
+        on the root device/within the charm directory.
+        """
+        device1 = os.path.join(self.tmp_dir, "device1")
+        device2 = "foo"
+        self.test_config.set("osd-devices", "{} {}".format(device1, device2))
+        self.assertEqual([device1], hooks.get_devices())
+
     def test_get_devices_symlink(self):
         """
         If a symlink is specified in osd-devices, get_devices() resolves