add and remove db record and reverse record

config.example.json

@@ -0,0 +1,13 @@
+{
+  "database": {
+    "host": "localhost",
+    "port": 5432,
+    "database": "powerdns",
+    "username": "powerdns",
+    "password": "password"
+  },
+  "domain": "local.example.com",
+  "reverseDomain": "1.168.192.in-addr.arpa",
+  "dhcpdFile": "/etc/dhcp/dhcpd.conf",
+  "recordTTL": 600
+}

localhostgen.py

@@ -0,0 +1,150 @@
+#! /usr/bin/env python3
+
+import argparse
+import json
+from time import time
+
+import psycopg2
+import sys
+
+
+class LocalHostGen:
+    db_config = None
+    db_instance = None
+
+    def __init__(self, db_config):
+        self.db_config = db_config
+
+    def connect(self):
+        self.db_instance = psycopg2.connect("dbname='%s' user='%s' host='%s' password='%s' port='%s'" %
+                                            (self.db_config['database'], self.db_config['username'],
+                                             self.db_config['host'], self.db_config['password'],
+                                             self.db_config['port']))
+
+    def disconnect(self):
+        if self.db_instance is not None:
+            self.db_instance.close()
+            self.db_instance = None
+
+    def get_domain_id(self, domain):
+        cur = self.db_instance.cursor()
+        cur.execute("SELECT id FROM domains WHERE name='%s'" % domain)
+        id = cur.fetchone()
+        cur.close()
+        if id is not None:
+            return id[0]
+        return None
+
+    def get_record_id(self, record):
+        cur = self.db_instance.cursor()
+        cur.execute("SELECT id FROM records WHERE name='%s'" % record)
+        id = cur.fetchone()
+        cur.close()
+        if id is not None:
+            return id[0]
+        return None
+
+    def get_record_content(self, record):
+        cur = self.db_instance.cursor()
+        cur.execute("SELECT content FROM records WHERE name='%s'" % record)
+        content = cur.fetchone()
+        cur.close()
+        if content is not None:
+            return content[0]
+        return None
+
+    def get_reversed_ip(self, ip):
+        return '.'.join(reversed(ip.split(".")))
+
+    def get_reverse_domain_record(self, reverse_domain, ip):
+        reversed_ip = self.get_reversed_ip(ip)
+        reverse_domain_part = reversed_ip
+        while not reverse_domain.startswith(reverse_domain_part):
+            reverse_domain_part = reverse_domain_part[reverse_domain_part.index('.') + 1:]
+        return reversed_ip[0:len(reversed_ip) - len(reverse_domain_part) - 1]
+
+    def insert_host(self, domain, record, content, ttl, type):
+        record_full = "%s.%s" % (record, domain)
+
+        record_id = self.get_record_id(record_full)
+        if record_id is None:
+            domain_id = self.get_domain_id(domain)
+            cur = self.db_instance.cursor()
+            cur.execute("INSERT INTO records (domain_id, name, type, content, ttl, prio, change_date,"
+                        "disabled, ordername, auth) VALUES ('%s', '%s', '%s', '%s', '%s', '0', '%s', 'f', NULL, 't')"
+                        "RETURNING id" % (domain_id, record_full, type, content, ttl, int(time())))
+            record_id = cur.fetchone()[0]
+            cur.close()
+            self.db_instance.commit()
+        return record_id
+
+    def delete_host(self, record):
+        cur = self.db_instance.cursor()
+        cur.execute("DELETE FROM records WHERE name='%s' RETURNING id" % record)
+        record_id = cur.fetchone()[0]
+        cur.close()
+        self.db_instance.commit()
+        return record_id
+
+    def create_host(self, domain, reverse_domain, host, ip, mac, ttl):
+        if self.db_instance is None:
+            self.connect()
+        reverse_domain_record = self.get_reverse_domain_record(reverse_domain, ip)
+        record_full = "%s.%s" % (host, domain)
+
+        self.insert_host(domain, host, ip, ttl, 'A')
+        self.insert_host(reverse_domain, reverse_domain_record, record_full, ttl, 'PTR')
+
+    def remove_host(self, domain, reverse_domain, host):
+        if self.db_instance is None:
+            self.connect()
+        record_full = "%s.%s" % (host, domain)
+        ip = self.get_record_content(record_full)
+        if ip is not None:
+            reverse_domain_record = self.get_reverse_domain_record(reverse_domain, ip)
+            reverse_domain_record_full = "%s.%s" %(reverse_domain_record, reverse_domain)
+            self.delete_host(record_full)
+            self.delete_host(reverse_domain_record_full)
+
+
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Manage local hosts for PowerDNS and isc-dhcp-server')
+    parser.add_argument('--host', help='The host to manage', required=True)
+    parser.add_argument('--config', dest='config', default='/etc/localhostgen/localhostgen.json',
+                        help='Configuration file path')
+
+    parser.add_argument('--create', help='Create a host', action='store_true')
+    parser.add_argument('--remove', help='Remove the host', action='store_true')
+
+    parser.add_argument('--mac', help='The MAC address of the new host')
+    parser.add_argument('--ip', help='The IP address of the new host')
+
+    args = parser.parse_args()
+
+    with open(args.config, "r") as f:
+        config = json.load(f)
+
+    host = args.host
+    ip = args.ip
+    mac = args.mac
+    ttl = config['recordTTL']
+
+    local_host_gen = LocalHostGen(config['database'])
+    local_host_gen.connect()
+
+    if args.create:
+        if ip is None or mac is None:
+            eprint("IP and MAC are required to create a host")
+            exit(1)
+        local_host_gen.create_host(config['domain'], config['reverseDomain'], host, ip, mac, ttl)
+    elif args.remove:
+        local_host_gen.remove_host(config['domain'], config['reverseDomain'], host)
+
+    local_host_gen.disconnect()
+
+
+main()