Put test id in zk chroot path

In an effort to help debug leaked zk chroots add the test id to the
chroot path so that we can see which tests are leaking.

Change-Id: I27047ecfa69d59964ac9ad4a03941b9826099420
diff --git a/tests/base.py b/tests/base.py
index 30ff7a1..4d358c9 100755
--- a/tests/base.py
+++ b/tests/base.py
@@ -1042,7 +1042,7 @@
 
 
 class ChrootedKazooFixture(fixtures.Fixture):
-    def __init__(self):
+    def __init__(self, test_id):
         super(ChrootedKazooFixture, self).__init__()
 
         zk_host = os.environ.get('NODEPOOL_ZK_HOST', 'localhost')
@@ -1059,13 +1059,15 @@
         else:
             self.zookeeper_port = int(port)
 
+        self.test_id = test_id
+
     def _setUp(self):
         # Make sure the test chroot paths do not conflict
         random_bits = ''.join(random.choice(string.ascii_lowercase +
                                             string.ascii_uppercase)
                               for x in range(8))
 
-        rand_test_path = '%s_%s' % (random_bits, os.getpid())
+        rand_test_path = '%s_%s_%s' % (random_bits, os.getpid(), self.test_id)
         self.zookeeper_chroot = "/nodepool_test/%s" % rand_test_path
 
         self.addCleanup(self._cleanup)
@@ -1491,7 +1493,8 @@
                 o.write(i.read())
 
     def setupZK(self):
-        self.zk_chroot_fixture = self.useFixture(ChrootedKazooFixture())
+        self.zk_chroot_fixture = self.useFixture(
+            ChrootedKazooFixture(self.id()))
         self.zk_config = '%s:%s%s' % (
             self.zk_chroot_fixture.zookeeper_host,
             self.zk_chroot_fixture.zookeeper_port,