journald compatible log level

src/netcup_dns/main.py

@@ -13,6 +13,8 @@ from nc_dnsapi import Client, DNSRecord
 from netcup_dns.exception import UnknownIPException, MultipleRecordsException
 from netcup_dns.record_dst_cache import RecordDestinationCache
 
+from src.netcup_dns.print_util import print_info, print_err
+
 
 def main():
     """
@@ -43,17 +45,25 @@ def main():
 
                 if type_ == 'A':
                     # Lazy: Only determine external IPv4 if an A record shall be updated.
+                    try:
                         destination = external_ipv4()
+                    except UnknownIPException as e:
+                        print_err(str(e))
+                        exit(1)
                 elif type_ == 'AAAA':
                     # Lazy: Only determine external IPv6 if an AAAA record shall be updated.
+                    try:
                         destination = external_ipv6()
+                    except UnknownIPException as e:
+                        print_err(str(e))
+                        exit(1)
                 else:
                     raise ValueError(f'DNS record type {type_} is not supported.')
 
                 if update_record_destination(api, domain, hostname, type_, destination, cache):
-                    print(f'Set {hostname}.{domain} {type_} record to {destination}')
+                    print_info(f'Set {hostname}.{domain} {type_} record to {destination}')
                 else:
-                    print(f'The {hostname}.{domain} {type_} record points already to {destination}')
+                    print_info(f'The {hostname}.{domain} {type_} record points already to {destination}')
 
 
 def parse_args():
@@ -240,6 +250,7 @@ def external_ipv4(timeout: float = 5, endpoints: list[str] = None) -> str:
     :param endpoints: List of webservices that return ones public IPv4 address.
     :argument timeout: Timeout for each webservice in seconds.
     :return: Public IPv4 address.
+    :raises UnknownIPException:
     """
     return external_ip(ipaddress.IPv4Address, timeout, endpoints)
 
@@ -250,6 +261,7 @@ def external_ipv6(timeout: float = 5, endpoints: list[str] = None) -> str:
     :param endpoints: List of webservices that return ones public IPv6 address.
     :argument timeout: Timeout for each webservice in seconds.
     :return: Public IPv6 address.
+    :raises UnknownIPException:
     """
     return external_ip(ipaddress.IPv6Address, timeout, endpoints)
 

src/netcup_dns/print_util.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+import sys
+
+
+# https://www.freedesktop.org/software/systemd/man/latest/sd-daemon.html
+#
+# define SD_EMERG   "<0>"  /* system is unusable */
+# define SD_ALERT   "<1>"  /* action must be taken immediately */
+# define SD_CRIT    "<2>"  /* critical conditions */
+# define SD_ERR     "<3>"  /* error conditions */
+# define SD_WARNING "<4>"  /* warning conditions */
+# define SD_NOTICE  "<5>"  /* normal but significant condition */
+# define SD_INFO    "<6>"  /* informational */
+# define SD_DEBUG   "<7>"  /* debug-level messages */
+
+def print_emerg(message: object):
+    do_print('<0> ', message, file=sys.stderr)
+
+
+def print_alert(message: object):
+    do_print('<1> ', message, file=sys.stderr)
+
+
+def print_crit(message: object):
+    do_print('<2> ', message, file=sys.stderr)
+
+
+def print_err(message: object):
+    do_print('<3> ', message, file=sys.stderr)
+
+
+def print_warning(message: object):
+    do_print('<4> ', message, file=sys.stderr)
+
+
+def print_notice(message: object):
+    do_print('<5> ', message)
+
+
+def print_info(message: object):
+    do_print('<6> ', message)
+
+
+def print_debug(message: object):
+    do_print('<7> ', message)
+
+
+def do_print(line_prefix: str, message: object, file=sys.stdout) -> None:
+    # Prefix each line in str(object) with `line_prefix`.
+    prefixed = line_prefix + str(message).replace('\n', '\n' + line_prefix)
+    print(prefixed, file=file)