ipatests: configure Network Manager not to manage resolv.conf

For the duration of the test, makes resolv.conf unmanaged.
If NetworkManager is not running, nothing is changed.

https://fedorahosted.org/freeipa/ticket/5331

Reviewed-By: Martin Basti <mbasti@redhat.com>

ipaplatform/base/paths.py

@@ -354,6 +354,6 @@ class BasePathNamespace(object):
     DB2BAK = '/usr/sbin/db2bak'
     KDCPROXY_CONFIG = '/etc/ipa/kdcproxy/kdcproxy.conf'
     CERTMONGER = '/usr/sbin/certmonger'
-
+    NETWORK_MANAGER_CONFIG_DIR = '/etc/NetworkManager/conf.d'
 
 path_namespace = BasePathNamespace

ipatests/test_integration/tasks.py

@@ -41,6 +41,8 @@ from ipalib.util import get_reverse_zone_default
 
 log = log_mgr.get_logger(__name__)
 
+IPATEST_NM_CONFIG = '20-ipatest-unmanaged-resolv.conf'
+
 
 def check_arguments_are(slice, instanceof):
     """
@@ -80,6 +82,7 @@ def prepare_host(host):
 def apply_common_fixes(host):
     fix_etc_hosts(host)
     fix_hostname(host)
+    modify_nm_resolv_conf_settings(host)
     fix_resolv_conf(host)
 
 
@@ -125,6 +128,38 @@ def fix_hostname(host):
     host.run_command('hostname > %s' % ipautil.shell_quote(backupname))
 
 
+def host_service_active(host, service):
+    res = host.run_command(['systemctl', 'is-active', '--quiet', service],
+                           raiseonerr=False)
+
+    if res.returncode == 0:
+        return True
+    else:
+        return False
+
+
+def modify_nm_resolv_conf_settings(host):
+    if not host_service_active(host, 'NetworkManager'):
+        return
+
+    config = "[main]\ndns=none\n"
+    path = os.path.join(paths.NETWORK_MANAGER_CONFIG_DIR, IPATEST_NM_CONFIG)
+
+    host.put_file_contents(path, config)
+    host.run_command(['systemctl', 'restart', 'NetworkManager'],
+                     raiseonerr=False)
+
+
+def undo_nm_resolv_conf_settings(host):
+    if not host_service_active(host, 'NetworkManager'):
+        return
+
+    path = os.path.join(paths.NETWORK_MANAGER_CONFIG_DIR, IPATEST_NM_CONFIG)
+    host.run_command(['rm', '-f', path], raiseonerr=False)
+    host.run_command(['systemctl', 'restart', 'NetworkManager'],
+                     raiseonerr=False)
+
+
 def fix_resolv_conf(host):
     backup_file(host, paths.RESOLV_CONF)
     lines = host.get_file_contents(paths.RESOLV_CONF).splitlines()
@@ -153,6 +188,7 @@ def fix_apache_semaphores(master):
 def unapply_fixes(host):
     restore_files(host)
     restore_hostname(host)
+    undo_nm_resolv_conf_settings(host)
 
     # Clean up the test directory
     host.run_command(['rm', '-rvf', host.config.test_dir])