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

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

1 files changed, 113 insertions, 0 deletions

diff --git a/src/op_mode/dns_dynamic.py b/src/op_mode/dns_dynamic.py
new file mode 100755
index 000000000..d41a74db3
--- /dev/null
+++ b/src/op_mode/dns_dynamic.py
@@ -0,0 +1,113 @@
+#!/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
+import argparse
+import sys
+import time
+from tabulate import tabulate
+
+from vyos.config import Config
+from vyos.template import is_ipv4, is_ipv6
+from vyos.util import call
+
+cache_file = r'/run/ddclient/ddclient.cache'
+
+columns = {
+    'host':        'Hostname',
+    'ipv4':        'IPv4 address',
+    'status-ipv4': 'IPv4 status',
+    'ipv6':        'IPv6 address',
+    'status-ipv6': 'IPv6 status',
+    'mtime':       'Last update',
+}
+
+
+def _get_formatted_host_records(host_data):
+    data_entries = []
+    for entry in host_data:
+        data_entries.append([entry.get(key) for key in columns.keys()])
+
+    header = columns.values()
+    output = tabulate(data_entries, header, numalign='left')
+    return output
+
+
+def show_status():
+    # A ddclient status file might not always exist
+    if not os.path.exists(cache_file):
+        sys.exit(0)
+
+    data = []
+
+    with open(cache_file, 'r') as f:
+        for line in f:
+            if line.startswith('#'):
+                continue
+
+            props = {}
+            # ddclient cache rows have properties in 'key=value' format separated by comma
+            # we pick up the ones we are interested in
+            for kvraw in line.split(' ')[0].split(','):
+                k, v = kvraw.split('=')
+                if k in list(columns.keys()) + ['ip', 'status']:  # ip and status are legacy keys
+                    props[k] = v
+
+            # Extract IPv4 and IPv6 address and status from legacy keys
+            # Dual-stack isn't supported in legacy format, 'ip' and 'status' are for one of IPv4 or IPv6
+            if 'ip' in props:
+                if is_ipv4(props['ip']):
+                    props['ipv4'] = props['ip']
+                    props['status-ipv4'] = props['status']
+                elif is_ipv6(props['ip']):
+                    props['ipv6'] = props['ip']
+                    props['status-ipv6'] = props['status']
+                del props['ip']
+
+            # Convert mtime to human readable format
+            if 'mtime' in props:
+                props['mtime'] = time.strftime(
+                    "%Y-%m-%d %H:%M:%S", time.localtime(int(props['mtime'], base=10)))
+
+            data.append(props)
+
+    print(_get_formatted_host_records(data))
+
+
+def update_ddns():
+    call('systemctl stop ddclient.service')
+    if os.path.exists(cache_file):
+        os.remove(cache_file)
+    call('systemctl start ddclient.service')
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument("--status", help="Show DDNS status", action="store_true")
+    group.add_argument("--update", help="Update DDNS on a given interface", action="store_true")
+    args = parser.parse_args()
+
+    # Do nothing if service is not configured
+    c = Config()
+    if not c.exists_effective('service dns dynamic'):
+        print("Dynamic DNS not configured")
+        sys.exit(1)
+
+    if args.status:
+        show_status()
+    elif args.update:
+        update_ddns()