Merge pull request #2005 from indrajitr/ddclient-improvement-round-2

dns: T5144: Modernize dynamic dns operation (round 2)

1 files changed, 134 insertions, 0 deletions

diff --git a/src/conf_mode/dns_dynamic.py b/src/conf_mode/dns_dynamic.py
new file mode 100755
index 000000000..f97225370
--- /dev/null
+++ b/src/conf_mode/dns_dynamic.py
@@ -0,0 +1,134 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018-2020 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+
+from sys import exit
+
+from vyos.config import Config
+from vyos.configdict import dict_merge
+from vyos.template import render
+from vyos.util import call
+from vyos.xml import defaults
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+config_file = r'/run/ddclient/ddclient.conf'
+systemd_override = r'/run/systemd/system/ddclient.service.d/override.conf'
+
+# Protocols that require zone
+zone_allowed = ['cloudflare', 'godaddy', 'hetzner', 'gandi', 'nfsn']
+
+# Protocols that do not require username
+username_unnecessary = ['1984', 'cloudflare', 'cloudns', 'duckdns', 'freemyip', 'hetzner', 'keysystems', 'njalla']
+
+# Protocols that support both IPv4 and IPv6
+dualstack_supported = ['cloudflare', 'dyndns2', 'freedns', 'njalla']
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+
+    base_level = ['service', 'dns', 'dynamic']
+    if not conf.exists(base_level):
+        return None
+
+    dyndns = conf.get_config_dict(base_level, key_mangling=('-', '_'), get_first_key=True)
+
+    for address in dyndns['address']:
+        # Apply service specific defaults (stype = ['rfc2136', 'service'])
+        for svc_type in dyndns['address'][address]:
+            default_values = defaults(base_level + ['address', svc_type])
+            for svc_cfg in dyndns['address'][address][svc_type]:
+                dyndns['address'][address][svc_type][svc_cfg] = dict_merge(
+                    default_values, dyndns['address'][address][svc_type][svc_cfg])
+
+    dyndns['config_file'] = config_file
+    return dyndns
+
+def verify(dyndns):
+    # bail out early - looks like removal from running config
+    if not dyndns:
+        return None
+
+    for address in dyndns['address']:
+        # RFC2136 - configuration validation
+        if 'rfc2136' in dyndns['address'][address]:
+            for config in dyndns['address'][address]['rfc2136'].values():
+                for field in ['host_name', 'zone', 'server', 'key']:
+                    if field not in config:
+                        raise ConfigError(f'"{field.replace("_", "-")}" is required for RFC2136 '
+                                          f'based Dynamic DNS service on "{address}"')
+
+        # Dynamic DNS service provider - configuration validation
+        if 'service' in dyndns['address'][address]:
+            for service, config in dyndns['address'][address]['service'].items():
+                error_msg = f'is required for Dynamic DNS service "{service}" on "{address}"'
+
+                for field in ['host_name', 'password', 'protocol']:
+                    if field not in config:
+                        raise ConfigError(f'"{field.replace("_", "-")}" {error_msg}')
+
+                if config['protocol'] in zone_allowed and 'zone' not in config:
+                        raise ConfigError(f'"zone" {error_msg}')
+
+                if config['protocol'] not in zone_allowed and 'zone' in config:
+                        raise ConfigError(f'"{config["protocol"]}" does not support "zone"')
+
+                if config['protocol'] not in username_unnecessary:
+                    if 'username' not in config:
+                        raise ConfigError(f'"username" {error_msg}')
+
+                if config['ip_version'] == 'both':
+                    if config['protocol'] not in dualstack_supported:
+                        raise ConfigError(f'"{config["protocol"]}" does not support IPv4 and IPv6 at the same time')
+                    # dyndns2 protocol in ddclient honors dual stack only for dyn.com (dyndns.org)
+                    if config['protocol'] == 'dyndns2' and 'server' in config and config['server'] != 'members.dyndns.org':
+                        raise ConfigError(f'"{config["protocol"]}" for "{config["server"]}" does not support IPv4 and IPv6 at the same time')
+
+    return None
+
+def generate(dyndns):
+    # bail out early - looks like removal from running config
+    if not dyndns:
+        return None
+
+    render(config_file, 'dns-dynamic/ddclient.conf.j2', dyndns)
+    render(systemd_override, 'dns-dynamic/override.conf.j2', dyndns)
+    return None
+
+def apply(dyndns):
+    if not dyndns:
+        call('systemctl stop ddclient.service')
+        if os.path.exists(config_file):
+            os.unlink(config_file)
+    else:
+        call('systemctl restart ddclient.service')
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)