Status db mirror menggunakan query

CHANGES.txt

+0.9 7-7-2024
+------------
+- Status database mirror kini menggunakan query ketimbang baca log file.
+
 0.8.2 14-3-2024
 ---------------
 - Bug fixed pada log_table saat diterapkan pada tabel ke-2. Ini terkait cache

mirror_status/__init__.py

 import sys
 import os
-import re
 from argparse import ArgumentParser
 from configparser import ConfigParser
 from subprocess import (
     PIPE,
     Popen,
     )
-from maintenance import is_mirror
-from .structure import (
-    RE_OK,
-    RE_TIMEOUT,
-    RE_NO_ROUTE,
-    RE_REMOVED,
-    RE_INVALID,
-    RE_ANY,
+from maintenance import (
+    is_mirror,
+    Reader,
     )
 
 
-REC_OK = re.compile(RE_OK)
-REC_TIMEOUT = re.compile(RE_TIMEOUT)
-REC_NO_ROUTE = re.compile(RE_NO_ROUTE)
-REC_REMOVED = re.compile(RE_REMOVED)
-REC_INVALID = re.compile(RE_INVALID)
-REC_ANY = re.compile(RE_ANY)
-
-PARSER = [
-    (REC_OK, 'OK'),
-    (REC_TIMEOUT, 'network bermasalah'),
-    (REC_NO_ROUTE, 'network bermasalah'),
-    (REC_REMOVED, 'FATAL, harus dibuat ulang'),
-    (REC_INVALID, 'WARNING, invalid record length'),
-    (REC_ANY, 10)]
-
-
-def parse_log(s):
-    for regex, message in PARSER:
-        match = regex.search(s)
-        if not match:
-            continue
-        if isinstance(message, int):
-            return match.group(message)
-        return message
-
-
 def get_option(argv):
     parser = ArgumentParser()
     parser.add_argument('config')
@@ -55,6 +23,20 @@ def mkdir(name):
         os.mkdir(name)
 
 
+def is_active(conf_file):
+    r = Reader(conf_file)
+    port = r['port']
+    cmd_psql = f'psql -p {port} -c "SELECT pg_is_in_recovery()"'
+    cmd1 = ['su', '-', 'postgres', '-c', cmd_psql]
+    cmd2 = ['sed', '-n', '3p']
+    p1 = Popen(cmd1, stdout=PIPE)
+    p2 = Popen(cmd2, stdin=p1.stdout, stdout=PIPE)
+    out, err = p2.communicate()
+    if not err:
+        s = out.decode('utf-8')
+        return s.strip()
+
+
 def main(argv=sys.argv[1:]):
     option = get_option(argv)
     conf_file = option.config
@@ -71,17 +53,9 @@ def main(argv=sys.argv[1:]):
             pg_conf = os.path.join(cluster_conf_dir, 'postgresql.conf')
             if not is_mirror(pg_conf):
                 continue
-            log_file = '/var/log/postgresql/'\
-                       f'postgresql-{version}-{cluster}.log'
-            c1 = ['grep', '^20', log_file]
-            c2 = ['tail', '-n', '1']
-            p1 = Popen(c1, stdout=PIPE)
-            p2 = Popen(c2, stdin=p1.stdout, stdout=PIPE)
-            new_status, stderr = p2.communicate()
-            new_status = parse_log(new_status.decode('utf8'))
-            if not new_status:
-                continue
-            print(f'{cluster} {new_status}')
+            new_status = is_active(pg_conf)
+            label = new_status and 'OK' or 'GAGAL'
+            print(f'{version} {cluster} {label}')
             status_file = f'postgresql-{version}-{cluster}.txt'
             status_file = os.path.join(status_dir, status_file)
             if os.path.exists(status_file):

mirror_status/structure.py

-RE_PREFIX = r'([\d]*)-([\d]*)-([\d]*) ([\d]*):([\d]*):([\d]*).([\d]*) '\
-            r'([A-Z]*) .([\d]*). '
-
-# 2023-05-21 09:56:50.553 WIB [2429] LOG:  streaming replication successfully
-# connected to primary
-# 2022-01-03 07:04:42.728 WIB [1268975] LOG:  started streaming WAL from
-# primary at 3/B6000000 on timeline 1
-# 2023-05-09 07:29:49.335 WIB [3811560] DETAIL:  Last completed transaction was
-# at log time 2023-05-09 07:28:19.547035+07.
-RE_OK = RE_PREFIX + '(LOG:  streaming replication successfully|'\
-        'LOG:  started streaming WAL|DETAIL:  Last completed)'
-
-# 2022-01-03 07:04:10.757 WIB [1258171] FATAL:  terminating walreceiver due to
-# timeout
-RE_TIMEOUT = RE_PREFIX + 'FATAL:  terminating walreceiver due to timeout'
-
-# 2022-01-06 08:55:58.797 WIB [1983436] FATAL:  could not connect to the
-# primary server: connection to server at "10.8.18.1", port 5432 failed:
-# Koneksi kehabisan waktu
-RE_NO_ROUTE = RE_PREFIX + 'FATAL:  could not connect to'
-
-# 2022-01-03 07:27:16.064 WIB [22592] FATAL:  could not receive data from WAL
-# stream: ERROR:  requested WAL segment 00000001000000A5000000A9 has already
-# been removed
-RE_REMOVED = RE_PREFIX + '(.*) removed'
-
-# 2022-01-05 04:22:58.394 WIB [1237] LOG:  invalid record length
-RE_INVALID = RE_PREFIX + 'LOG:  invalid'
-
-RE_ANY = RE_PREFIX + 'FATAL: (.*)'