Save port membership for patch interface

Patch interface added to Linux bridge during the control plane
cutover, but not saved to configuration file for persistence.

Add function to add port to bridge's configuration.

Change-Id: If40bebf384b24d6af5e42798fbf6bc2993dc4795
Closes-bug: 1576150

octane/tests/test_network.py

@@ -9,10 +9,13 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
+
+import pytest
 import subprocess
 
 from mock import call
 from mock import Mock
+from octane.tests import util as test_util
 from octane.util import network
 
 
@@ -310,3 +313,27 @@ DEPLOYMENT_INFO_7_0 = {
         }]
     }
 }
+
+
+IFACE_BASE = b"auto br-ex\niface br-ex inet static\n"
+IFACE_ADDR = b"address 10.109.1.4/24\ngateway 10.109.1.1\n"
+IFACE_SINGLEPORT = IFACE_BASE + b"bridge_ports eth0\n"
+IFACE_DEFAULT = IFACE_SINGLEPORT + IFACE_ADDR
+IFACE_TESTPORT = b"bridge_ports test-iface\n"
+IFACE_MULTIPORT = IFACE_BASE + IFACE_TESTPORT
+IFACE_MULTIPORT_EXPECTED = IFACE_BASE + b"bridge_ports eth0 test-iface\n"
+
+
+@pytest.mark.parametrize("content,expected_content", [
+    (IFACE_BASE, IFACE_SINGLEPORT),
+    (IFACE_DEFAULT, IFACE_DEFAULT),
+    (IFACE_MULTIPORT, IFACE_MULTIPORT_EXPECTED),
+])
+@pytest.mark.parametrize("bridge,port", [
+    ('br-ex', {'name': 'eth0'}),
+])
+def test_save_port_lnx(mocker, node, content, expected_content, bridge, port):
+    filename = '/etc/network/interfaces.d/ifcfg-{0}'.format(bridge)
+    with test_util.mock_update_file(mocker, node, content, expected_content,
+                                    filename):
+        network.save_port_lnx(node, bridge, port)

octane/util/network.py

@@ -11,6 +11,7 @@
 # under the License.
 
 import logging
+import os
 import re
 import subprocess
 
@@ -317,6 +318,28 @@ create_port_providers = {
 }
 
 
+def save_port_lnx(node, bridge, port):
+    ifaces_path = '/etc/network/interfaces.d'
+    bridge_file = os.path.join(ifaces_path, 'ifcfg-{0}'.format(bridge))
+    sftp = ssh.sftp(node)
+    with ssh.update_file(sftp, bridge_file) as (old, new):
+        found_bridge_port_line = False
+        for line in old:
+            if line.startswith('bridge_ports'):
+                found_bridge_port_line = True
+                if port['name'] not in line:
+                    option, _, ports = line.rstrip().partition(' ')
+                    line = "{0} {1} {2}\n".format(option, port['name'], ports)
+            new.write(line)
+        if not found_bridge_port_line:
+            new.write('bridge_ports {0}\n'.format(port['name']))
+
+
+save_port_providers = {
+    'lnx': save_port_lnx,
+}
+
+
 def create_patch_ports(node, host_config):
     for bridge in magic_consts.BRIDGES:
         port, provider = ts.get_patch_port_action(host_config, bridge)
@@ -324,6 +347,9 @@ def create_patch_ports(node, host_config):
         cmds = create_port_cmd(bridge, port)
         for cmd in cmds:
             ssh.call(cmd, node=node)
+        save_port_func = save_port_providers.get(provider)
+        if save_port_func:
+            save_port_func(node, bridge, port)
 
 
 def flush_arp(node):