ipatests: simplify fixture

Fixture enable_smb_client_dns_lookup_kdc had an unobvious structure
"contextmanage inside pytest fixture". Replaced with simple pytest
fixture.

Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

ipatests/test_integration/test_smb.py

@@ -14,7 +14,6 @@ import re
 import os
 
 import pytest
-from contextlib import contextmanager
 
 from ipatests.test_integration.base import IntegrationTest
 from ipatests.pytest_ipa.integration import tasks
@@ -78,18 +77,22 @@ class TestSMB(IntegrationTest):
         for user in [cls.ipa_user1, cls.ipa_user2, cls.ad_user]:
             tasks.run_command_as_user(cls.smbserver, user, ['stat', '.'])
 
+    def enable_dns_lookup_kdc(self, host):
+        with tasks.FileBackup(host, paths.KRB5_CONF):
+            krb5_conf = host.get_file_contents(
+                paths.KRB5_CONF, encoding='utf-8')
+            krb5_conf = krb5_conf.replace(
+                'dns_lookup_kdc = false', 'dns_lookup_kdc = true')
+            host.put_file_contents(paths.KRB5_CONF, krb5_conf)
+            yield
+
     @pytest.fixture
     def enable_smb_client_dns_lookup_kdc(self):
-        @contextmanager
-        def _enable_for(smbclient):
-            with tasks.FileBackup(smbclient, paths.KRB5_CONF):
-                krb5_conf = smbclient.get_file_contents(
-                    paths.KRB5_CONF, encoding='utf-8')
-                krb5_conf = krb5_conf.replace(
-                    'dns_lookup_kdc = false', 'dns_lookup_kdc = true')
-                smbclient.put_file_contents(paths.KRB5_CONF, krb5_conf)
-                yield
-        return _enable_for
+        yield from self.enable_dns_lookup_kdc(self.smbclient)
+
+    @pytest.fixture
+    def enable_smb_server_dns_lookup_kdc(self):
+        yield from self.enable_dns_lookup_kdc(self.smbserver)
 
     @pytest.fixture
     def samba_share_public(self):
@@ -318,15 +321,14 @@ class TestSMB(IntegrationTest):
 
     def test_smb_access_for_ad_user_at_ipa_client(
             self, enable_smb_client_dns_lookup_kdc):
-        with enable_smb_client_dns_lookup_kdc(self.smbclient):
-            samba_share = {
-                'name': 'homes',
-                'server_path': '/home/{}/{}'.format(self.ad.domain.name,
-                                                    self.ad_user_login),
-                'unc': '//{}/homes'.format(self.smbserver.hostname)
-            }
-            self.check_smb_access_at_ipa_client(
-                self.ad_user, self.ad_user_password, samba_share)
+        samba_share = {
+            'name': 'homes',
+            'server_path': '/home/{}/{}'.format(self.ad.domain.name,
+                                                self.ad_user_login),
+            'unc': '//{}/homes'.format(self.smbserver.hostname)
+        }
+        self.check_smb_access_at_ipa_client(
+            self.ad_user, self.ad_user_password, samba_share)
 
     def test_smb_mount_and_access_by_different_users(self, samba_share_public):
         user1 = self.ipa_user1
@@ -346,8 +348,7 @@ class TestSMB(IntegrationTest):
         finally:
             self.cleanup_mount(mount_point)
 
-    def test_smb_service_s4u2self(
-            self, enable_smb_client_dns_lookup_kdc):
+    def test_smb_service_s4u2self(self, enable_smb_server_dns_lookup_kdc):
         """Test S4U2Self operation by IPA service
            against both AD and IPA users
         """
@@ -358,25 +359,24 @@ class TestSMB(IntegrationTest):
         {print_pac} -k /etc/samba/samba.keytab -E impersonate {user_princ}
         klist -f
         """)
-        with enable_smb_client_dns_lookup_kdc(self.smbserver):
-            principal = 'cifs/{hostname}'.format(
-                hostname=self.smbserver.hostname)
-            # Copy ipa-print-pac to SMB server
-            # We can do so because Samba and GSSAPI libraries
-            # are present there
-            print_pac = self.master.get_file_contents(
-                os.path.join(paths.LIBEXEC_IPA_DIR, "ipa-print-pac"))
-            result = self.smbserver.run_command(['mktemp'])
-            tmpname = result.stdout_text.strip()
-            self.smbserver.put_file_contents(tmpname, print_pac)
-            self.smbserver.run_command(['chmod', 'a+x', tmpname])
-            for user in (self.ad_user, self.ipa_user1,):
-                shell_script = script.format(principal=principal,
-                                             user_princ=user,
-                                             print_pac=tmpname)
-                self.smbserver.run_command(['/bin/bash', '-s', '-e'],
-                                           stdin_text=shell_script)
-            self.smbserver.run_command(['rm', '-f', tmpname])
+        principal = 'cifs/{hostname}'.format(
+            hostname=self.smbserver.hostname)
+        # Copy ipa-print-pac to SMB server
+        # We can do so because Samba and GSSAPI libraries
+        # are present there
+        print_pac = self.master.get_file_contents(
+            os.path.join(paths.LIBEXEC_IPA_DIR, "ipa-print-pac"))
+        result = self.smbserver.run_command(['mktemp'])
+        tmpname = result.stdout_text.strip()
+        self.smbserver.put_file_contents(tmpname, print_pac)
+        self.smbserver.run_command(['chmod', 'a+x', tmpname])
+        for user in (self.ad_user, self.ipa_user1,):
+            shell_script = script.format(principal=principal,
+                                         user_princ=user,
+                                         print_pac=tmpname)
+            self.smbserver.run_command(['/bin/bash', '-s', '-e'],
+                                       stdin_text=shell_script)
+        self.smbserver.run_command(['rm', '-f', tmpname])
         tasks.kdestroy_all(self.smbserver)
 
     def test_smb_mount_fails_without_kerberos_ticket(self, samba_share_public):