Catch ldap ImportError

Since the `ldap` module isn't a requirement, we need to guard against it not
being present.

One reason this is needed is that we generate sample configs by walking the
module import tree. If a module isn't importable--because a depenency isn't
met, for example--the module's configs are omitted from the sample config,
requiring the developer to manually add them back.

Fixes bug 1208560

Change-Id: Ie23b7fad118ecadabf7e36703934fa933f4e8c50

nova/network/ldapdns.py

@@ -12,7 +12,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import ldap
+try:
+    import ldap
+except ImportError:
+    # This module needs to be importable despite ldap not being a requirement
+    ldap = None
+
 import time
 
 from oslo.config import cfg
@@ -313,6 +318,9 @@ class LdapDNS(dns_driver.DNSDriver):
     """
 
     def __init__(self):
+        if not ldap:
+            raise ImportError(_('ldap not installed'))
+
         self.lobj = ldap.initialize(CONF.ldap_dns_url)
         self.lobj.simple_bind_s(CONF.ldap_dns_user,
                                 CONF.ldap_dns_password)

test-requirements.txt

@@ -7,9 +7,6 @@ mox==0.5.3
 MySQL-python
 psycopg2
 pylint==0.25.2
-# Imported by ldapdns so required to generate
-# the sample configuration file
-python-ldap==2.3.13
 python-subunit
 setuptools_git>=0.4
 sphinx>=1.1.2