Fix quoting for devstack_localrc arguments

This is a combination of the following commits:
- "Quote devstack_localrc arguments"
  https://review.opendev.org/636078
  Ia63a53d745dfea7262bcdb5d46425f431c3ccfe5
- "Fix double quoting issue when writing localconf"
  https://review.opendev.org/648951
  I92146e04731efc6dcc632ae6c3a7c374e783cdba

They have been merged together because the first commit introduces
a bug, and it looks a bit pointless to deliberately introduce
a potentially breaking change on the process of backporting a fix.

Co-Authored-By: Ian Wienand <iwienand@redhat.com>
Co-Authored-By: Jens Harbott <j.harbott@x-ion.de>

Change-Id: Ia703af54a7131843fc2b0ae34efcfe0f5507acbf

roles/write-devstack-local-conf/library/devstack_local_conf.py

@@ -252,7 +252,11 @@ class LocalConf(object):
         if localrc:
             vg = VarGraph(localrc)
             for k, v in vg.getVars():
-                self.localrc.append('{}={}'.format(k, v))
+                # Avoid double quoting
+                if len(v) and v[0]=='"':
+                    self.localrc.append('{}={}'.format(k, v))
+                else:
+                    self.localrc.append('{}="{}"'.format(k, v))
                 if k == 'LIBS_FROM_GIT':
                     lfg = True
                 elif k == 'TEMPEST_PLUGINS':

roles/write-devstack-local-conf/library/test.py

@@ -185,7 +185,25 @@ class TestDevstackLocalConf(unittest.TestCase):
             for line in f:
                 if line.startswith('LIBS_FROM_GIT'):
                     lfg = line.strip().split('=')[1]
-        self.assertEqual('oslo.db', lfg)
+        self.assertEqual('"oslo.db"', lfg)
+
+    def test_avoid_double_quote(self):
+        "Test that there a no duplicated quotes"
+        localrc = {'TESTVAR': '"quoted value"'}
+        p = dict(localrc=localrc,
+                 base_services=[],
+                 base_dir='./test',
+                 path=os.path.join(self.tmpdir, 'test.local.conf'),
+                 projects={})
+        lc = self._init_localconf(p)
+        lc.write(p['path'])
+
+        testvar = None
+        with open(p['path']) as f:
+            for line in f:
+                if line.startswith('TESTVAR'):
+                    testvar = line.strip().split('=')[1]
+        self.assertEqual('"quoted value"', testvar)
 
     def test_plugin_circular_deps(self):
         "Test that plugins with circular dependencies fail"
@@ -265,7 +283,7 @@ class TestDevstackLocalConf(unittest.TestCase):
         lc.write(p['path'])
 
         tp = self._find_tempest_plugins_value(p['path'])
-        self.assertEqual('someplugin', tp)
+        self.assertEqual('"someplugin"', tp)
         self.assertEqual(len(lc.warnings), 1)