Switch to the value format for keystone check.

JSON output can be from cliff or clifftab.  This patch switches to the
value format to avoid this problem.

Change-Id: I5670c3f3d9b41cbe4ce424d548c573cf17770760
Closes-bug: 1533791

monitoring-for-openstack/oschecks/keystone.py

@@ -19,17 +19,13 @@
 # under the License.
 
 from oschecks import utils
-import json
 
 
 def _check_keystone_api():
     keystone = utils.Keystone()
 
     def check_token():
-        try:
-            return json.loads(keystone.run())['id']
-        except ValueError:
-            return ''
+        return keystone.run().strip()
 
     elapsed, token = utils.timeit(check_token)
     if not token:

monitoring-for-openstack/oschecks/utils.py

@@ -252,12 +252,12 @@ class Keystone(object):
 
 
     def run(self):
-        jformat = ['-f', 'json']
+        vformat = ['-f', 'value', '-c', 'id']
         command = ['token', 'issue']
-        jempty  = '{"id": ""}'
+        vempty  = ''
         if 'help' in sys.argv or '--help' in sys.argv or '-h' in sys.argv or len(sys.argv[1:]) == 0:
-            t = self.shell.run(command)
-            return jempty
+            self.shell.run(command)
+            return vempty
         else:
-            self.cmd = self.shell.run(sys.argv[1:] + command + jformat)
-            return self.shell.stdout.getvalue() or jempty
+            self.cmd = self.shell.run(sys.argv[1:] + command + vformat)
+            return self.shell.stdout.getvalue() or vempty