write dns info to networkd

Write dns info to networkd so it can be consumed by resolved if resolved
is enabled.

Change-Id: Ia7b55e9a538cc6f060bc08da85123d7bb3a4f73e

glean/cmd.py

@@ -31,6 +31,16 @@ from glean import systemlock
 from glean import utils
 from glean._vendor import distro
 
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
 log = logging.getLogger("glean")
 
 
@@ -312,7 +322,7 @@ def write_redhat_interfaces(interfaces, sys_interfaces, distro):
     return files_to_write
 
 
-def _write_networkd_interface(name, interfaces, files_struct=dict()):
+def _write_networkd_interface(name, interfaces, args, files_struct=dict()):
     vlans = []
     for interface in interfaces:
         iname = name
@@ -340,6 +350,15 @@ def _write_networkd_interface(name, interfaces, files_struct=dict()):
                 ('bond_mode' in interface)):
             if '[Network]' not in files_struct[network_file]:
                 files_struct[network_file]['[Network]'] = list()
+            if 'services' in interface:
+                for service in interface['services']:
+                    if service['type'] == 'dns':
+                        if not args.skip_dns:
+                            files_struct[network_file]['[Network]'].append(
+                                'DNS={address}'.format(
+                                    address=service['address']
+                                )
+                            )
         # dhcp network, set to yes if both dhcp6 and dhcp4 are set
         if interface['type'] == 'ipv4_dhcp':
             if 'DHCP=ipv6' in files_struct[network_file]['[Network]']:
@@ -492,7 +511,7 @@ def _write_networkd_interface(name, interfaces, files_struct=dict()):
     return files_struct
 
 
-def write_networkd_interfaces(interfaces, sys_interfaces):
+def write_networkd_interfaces(interfaces, sys_interfaces, args):
     files_to_write = dict()
     gen_intfs = {}
     files_struct = dict()
@@ -531,7 +550,7 @@ def write_networkd_interfaces(interfaces, sys_interfaces):
                 intf.get('link', intf['id']) for intf in interfs
                 if 'bond_mode' in intf)
         files_struct = _write_networkd_interface(
-            interface_name, interfs, files_struct)
+            interface_name, interfs, args, files_struct)
 
     for mac, iname in sorted(
             sys_interfaces.items(), key=lambda x: x[1]):
@@ -545,7 +564,7 @@ def write_networkd_interfaces(interfaces, sys_interfaces):
             continue
         interface = {'type': 'ipv4_dhcp', 'mac_address': mac}
         files_struct = _write_networkd_interface(
-            iname, [interface], files_struct)
+            iname, [interface], args, files_struct)
 
     for networkd_file in files_struct:
         file_contents = '# Automatically generated, do not edit\n'
@@ -912,10 +931,30 @@ def write_debian_interfaces(interfaces, sys_interfaces):
 
 
 def write_dns_info(dns_servers):
-    results = ""
+    resolve_confs = {}
+    resolv_nameservers = ""
     for server in dns_servers:
-        results += "nameserver {0}\n".format(server)
+        resolv_nameservers += "nameserver {0}\n".format(server)
-    return {'/etc/resolv.conf': results}
+    resolve_confs['/etc/resolv.conf'] = resolv_nameservers
+    # set up resolved if available
+    if os.path.isfile('/etc/systemd/resolved.conf'):
+        # read the existing config  so we only overwrite what's needed
+        resolved_conf = configparser.ConfigParser()
+        resolved_conf.read('/etc/systemd/resolved.conf')
+        # create config section if not created
+        if not resolved_conf.has_section('Resolve'):
+            resolved_conf.add_section('Resolve')
+        # write space separated dns servers
+        resolved_conf.set('Resolve', 'DNS', " ".join(dns_servers))
+        # use stringio to output the resulting config to string
+        # configparser only outputs to file descriptors
+        resolved_conf_fd = StringIO("")
+        resolved_conf.write(resolved_conf_fd)
+        resolved_conf_output = resolved_conf_fd.getvalue()
+        resolved_conf_fd.close()
+        # add the config to files to be written
+        resolve_confs['/etc/systemd/resolved.conf'] = resolved_conf_output
+    return resolve_confs
 
 
 def get_config_drive_interfaces(net):
@@ -1012,7 +1051,7 @@ def write_static_network_info(
         )
     elif args.distro in 'networkd':
         files_to_write.update(
-            write_networkd_interfaces(interfaces, sys_interfaces)
+            write_networkd_interfaces(interfaces, sys_interfaces, args)
         )
     else:
         return False

glean/tests/fixtures/rax-iad/mnt/config/openstack/latest/network_data.json

@@ -43,7 +43,17 @@
         }
       ],
       "ip_address": "2001:4802:7807:103:be76:4eff:fe20:d72f",
-      "id": "network1"
+      "id": "network1",
+      "services": [
+                {
+                    "address": "1111:2222:3333:4444::1234",
+                    "type": "dns"
+                },
+                {
+                    "address": "1.2.3.4",
+                    "type": "dns"
+                }
+            ]
     },
     {
       "network_id": "11111111-1111-1111-1111-111111111111",

glean/tests/fixtures/test/rax-iad.networkd.network.out.dns

@@ -0,0 +1,52 @@
+### Write /etc/resolv.conf
+nameserver 69.20.0.196
+nameserver 69.20.0.164
+### Write /etc/systemd/network/eth0.network
+# Automatically generated, do not edit
+[Match]
+MACAddress=bc:76:4e:20:d7:2f
+Name=eth0
+
+[Network]
+DNS=1.2.3.4
+DNS=1111:2222:3333:4444::1234
+IPv6AcceptRA=no
+
+[Address]
+Address=146.20.110.113/24
+
+[Address]
+Address=2001:4802:7807:103:be76:4eff:fe20:d72f/64
+
+[Route]
+Destination=0.0.0.0/0
+Gateway=146.20.110.1
+
+[Route]
+Destination=::/0
+Gateway=fe80::def
+
+[Route]
+Destination=fd30::/48
+Gateway=fe80::f001
+
+### Write /etc/systemd/network/eth1.network
+# Automatically generated, do not edit
+[Match]
+MACAddress=bc:76:4e:20:d7:33
+Name=eth1
+
+[Network]
+IPv6AcceptRA=no
+
+[Address]
+Address=10.210.32.174/19
+
+[Route]
+Destination=10.176.0.0/12
+Gateway=10.210.32.1
+
+[Route]
+Destination=10.208.0.0/12
+Gateway=10.210.32.1
+

glean/tests/test_glean.py

@@ -85,7 +85,7 @@ class TestGlean(base.BaseTestCase):
                      '/etc/conf.d', '/etc/init.d', '/etc/sysconfig/network',
                      '/etc/systemd/network')
         mock_files = ('/etc/resolv.conf', '/etc/hostname', '/etc/hosts',
-                      '/bin/systemctl')
+                      '/etc/systemd/resolved.conf', '/bin/systemctl')
         if (path.startswith(mock_dirs) or path in mock_files):
             try:
                 mock_handle = self.file_handle_mocks[path]
@@ -193,6 +193,9 @@ class TestGlean(base.BaseTestCase):
 
         output_filename = '%s.%s.network.out' % (provider, distro.lower())
         output_path = os.path.join(sample_data_path, 'test', output_filename)
+        if not skip_dns:
+            if os.path.exists(output_path + '.dns'):
+                output_path = output_path + '.dns'
 
         # Generate a list of (dest, content) into write_blocks to assert
         write_blocks = []
@@ -260,7 +263,8 @@ class TestGlean(base.BaseTestCase):
     # comes up with "--interface".  This simulates that.
     def test_glean_systemd(self):
         with mock.patch('glean.systemlock.Lock'):
-            self._assert_distro_provider(self.distro, self.style, 'eth0')
+            self._assert_distro_provider(self.distro, self.style,
+                                         'eth0', skip_dns=True)
 
     def test_glean_skip_dns(self):
         with mock.patch('glean.systemlock.Lock'):