refactor: use default=None for argparse append parameters (fix #540)

Author: markuslf

CHANGELOG.md

@@ -17,7 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 Build, CI/CD:
 
-* Remove `flatdict` dependency as it breaks builds on newer targets (RHEL 10, SLE 15/16) and no fix is available that also supports older targets (such as RHEL 8). This has the consequence that the [statuspal plugin](check-plugins/statuspal) is currently broken until the affected code is rewritten (tracked in [#1044](https://github.com/Linuxfabrik/monitoring-plugins/issues/1044)).
+* Remove `flatdict` dependency as it breaks builds on newer targets (RHEL 10, SLE 15/16) and no fix is available that also supports older targets (such as RHEL 8). The statuspal plugin has been rewritten to no longer depend on `flatdict` ([#1044](https://github.com/Linuxfabrik/monitoring-plugins/issues/1044)).
 
 
 ### Added
@@ -62,11 +62,13 @@ Grafana:
 Monitoring Plugins:
 
 * all plugins: ignore unknown arguments instead of generating an error (this helps with updating Icinga and Nagios service definitions considerably)
+* by-ssh, by-winrm, disk-usage, example, file-ownership, fs-ro, infomaniak-events, journald-query, logfile, matomo-reporting, mysql-logfile, php-status, pip-updates, systemd-unit: fix `append` parameters so that user-specified values replace defaults instead of being appended to them ([#540](https://github.com/Linuxfabrik/monitoring-plugins/issues/540))
 * file-count: stopping when number of files actually exceed thresholds, therefore dramatically faster for large directories
 * nextcloud-version: modernize code
 * php-status: always assume http://localhost/monitoring.php and, if not found, be tolerant
 * redis-status, valkey-status: modernize code and unify both plugins again after [PR #954](https://github.com/Linuxfabrik/monitoring-plugins/pull/954)
 * rocketchat-stats: improve output
+* statuspal: replace `flatdict` dependency with a recursive approach ([#1044](https://github.com/Linuxfabrik/monitoring-plugins/issues/1044))
 * updates: adapt to updated powershell.py library
 
 
@@ -79,6 +81,17 @@ Tools:
 
 ### Fixed
 
+Build, CI/CD:
+
+* requirements.txt: add missing `setuptools` dependency (required by `pbr`)
+
+
+Tools:
+
+* check2basket: fix missing `importlib.machinery` and `importlib.util` imports
+* check2basket: write `[]` as default value for `append` parameters with `default=None` in the Icinga Director basket
+
+
 Grafana:
 
 * Icinga Dashboard: Use a query instead of a constant service name to allow the dashboard to be used even if the service name differs

check-plugins/by-ssh/by-ssh

@@ -26,7 +26,7 @@ from lib.globals import (STATE_CRIT, STATE_OK,  # pylint: disable=C0413
 
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2025111401'
+__version__ = '2026033101'
 
 DESCRIPTION = """This plugin uses SSH to execute a command on a remote host,
                  returning STDOUT and, in case of failure, STDERR and the command's return code.
@@ -93,7 +93,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='CRIT_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -102,7 +102,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='CRIT_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -287,7 +287,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='WARN_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -296,7 +296,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='WARN_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     args, _ = parser.parse_known_args()
@@ -313,6 +313,16 @@ def main():
     except SystemExit:
         sys.exit(STATE_UNKNOWN)
 
+    # set default values for append parameters that were not specified
+    if args.CRIT_PATTERN is None:
+        args.CRIT_PATTERN = []
+    if args.CRIT_REGEX is None:
+        args.CRIT_REGEX = []
+    if args.WARN_PATTERN is None:
+        args.WARN_PATTERN = []
+    if args.WARN_REGEX is None:
+        args.WARN_REGEX = []
+
     # fetch data - run ssh
     cmd = "ssh {} {} {} {} {} {} {} {} '{}'@'{}' '{}'".format(
         "-4" if args.IPV4 else '',

check-plugins/by-winrm/by-winrm

@@ -24,7 +24,7 @@ from lib.globals import (STATE_CRIT, STATE_OK, STATE_UNKNOWN, STATE_WARN)
 
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2026030301'
+__version__ = '2026033101'
 
 DESCRIPTION = """This plugin executes PowerShell commands or scripts on remote Windows hosts via
 WinRM, supporting JEA. It returns standard output (STDOUT) and, in case of failure, standard error
@@ -82,7 +82,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='CRIT_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -91,7 +91,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='CRIT_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -178,7 +178,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='WARN_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -187,7 +187,7 @@ def parse_args():
              'Can be specified multiple times.',
         dest='WARN_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -251,6 +251,16 @@ def main():
     except SystemExit:
         sys.exit(STATE_UNKNOWN)
 
+    # set default values for append parameters that were not specified
+    if args.CRIT_PATTERN is None:
+        args.CRIT_PATTERN = []
+    if args.CRIT_REGEX is None:
+        args.CRIT_REGEX = []
+    if args.WARN_PATTERN is None:
+        args.WARN_PATTERN = []
+    if args.WARN_REGEX is None:
+        args.WARN_REGEX = []
+
     # fetch data - run WinRM command
     if args.TEST is None:
         timer_start = lib.time.now('float')

check-plugins/disk-usage/disk-usage

@@ -29,7 +29,7 @@ except ImportError:
 
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2025100601'
+__version__ = '2026033101'
 
 DESCRIPTION = 'Checks the used disk space, for each partition.'
 
@@ -84,7 +84,7 @@ def parse_args():
              'Includes are matched before excludes.',
         dest='EXCLUDE_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -96,7 +96,7 @@ def parse_args():
              'Includes are matched before excludes.',
         dest='EXCLUDE_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -110,7 +110,7 @@ def parse_args():
              'first (as file system types are machine dependent).',
         dest='FSTYPE',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -123,7 +123,7 @@ def parse_args():
              'Includes are matched before excludes.',
         dest='INCLUDE_PATTERN',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -135,7 +135,7 @@ def parse_args():
              'Includes are matched before excludes.',
         dest='INCLUDE_REGEX',
         action='append',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -153,7 +153,7 @@ def parse_args():
              'Can be specified multiple times.',
         action='append',
         dest='PERFDATA_REGEX',
-        default=[],
+        default=None,
     )
 
     parser.add_argument(
@@ -239,6 +239,21 @@ def main():
         args = parse_args()
     except SystemExit:
         sys.exit(STATE_UNKNOWN)
+
+    # set default values for append parameters that were not specified
+    if args.EXCLUDE_PATTERN is None:
+        args.EXCLUDE_PATTERN = []
+    if args.EXCLUDE_REGEX is None:
+        args.EXCLUDE_REGEX = []
+    if args.FSTYPE is None:
+        args.FSTYPE = []
+    if args.INCLUDE_PATTERN is None:
+        args.INCLUDE_PATTERN = []
+    if args.INCLUDE_REGEX is None:
+        args.INCLUDE_REGEX = []
+    if args.PERFDATA_REGEX is None:
+        args.PERFDATA_REGEX = []
+
     # args.WARN[0] = number, args.WARN[1] = unit, args.WARN[2] = USED|FREE
     try:
         float(args.WARN[0])

check-plugins/example/README.md

@@ -40,7 +40,8 @@ Hints for the Author (delete those):
 
 ```text
 usage: example [-h] [-V] [--always-ok] [-c CRIT] [--ignore-regex IGNORE_REGEX]
-               [--test TEST] --token TOKEN [-w WARN]
+               [--module MODULE] [--name NAME] [--test TEST] --token TOKEN
+               [-w WARN]
 
 A working Linuxfabrik monitoring plugin, written in Python 3, as a basis for
 further development, and much more text to help admins get this check up and
@@ -55,6 +56,10 @@ options:
                         Any english title matching this python regex will be
                         ignored (repeating). Example: '(?i)linuxfabrik' for a
                         case-insensitive search for "linuxfabrik".
+  --module MODULE       "modulename" to check (startswith), for example
+                        `--module json --module mbstring` (repeating)
+  --name NAME           Only check items with this name (repeating). If not
+                        specified, all items are checked.
   --test TEST           For unit tests. Needs "path-to-stdout-file,path-to-
                         stderr-file,expected-retc".
   --token TOKEN         Software API token

check-plugins/example/example

@@ -29,14 +29,15 @@ except ImportError:
 
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2025100601'
+__version__ = '2026033101'
 
 DESCRIPTION = """A working Linuxfabrik monitoring plugin, written in Python 3, as a basis for
 further development, and much more text to help admins get this check up and
 running."""
 
-DEFAULT_WARN = 80
 DEFAULT_CRIT = 90
+DEFAULT_MODULE = ['calendar', 'Core', 'ctype', 'date']
+DEFAULT_WARN = 80
 
 
 def parse_args():
@@ -67,17 +68,53 @@ def parse_args():
         default=DEFAULT_CRIT,
     )
 
+    # Append parameters must always use `default=None` instead of a list,
+    # because argparse appends user values to the default list instead of
+    # replacing it (see https://bugs.python.org/issue16399).
+    # After parsing, assign the actual defaults in main() if the value is
+    # still None.
+    #
+    # Case 1: "not specified" and "empty list" are the same thing.
+    #         The parameter is purely additive (e.g. patterns to match).
+    #         Assign `[]` as the default in main().
     parser.add_argument(
         '--ignore-regex',
         help='Any english title matching this python regex will be ignored '
              '(repeating). '
              'Example: \'(?i)linuxfabrik\' for a case-insensitive search for '
              '"linuxfabrik".',
         action='append',
-        default=[],
+        default=None,
         dest='IGNORE_REGEX',
     )
 
+    # Case 2: "not specified" and "empty list" are the same thing, but there
+    #         is a non-empty default list that should be used if the user
+    #         does not specify any values.
+    #         Assign `DEFAULT_X` as the default in main().
+    parser.add_argument(
+        '--module',
+        help='"modulename" to check (startswith), for example '
+             '`--module json --module mbstring` (repeating)',
+        dest='MODULE',
+        action='append',
+        default=None,
+    )
+
+    # Case 3: "not specified" means something different than "empty list".
+    #         For example, None = check all items, list = filter to only
+    #         the specified items.
+    #         Do NOT assign a default in main(). Instead, check for None
+    #         where the parameter is used: `if args.X is not None`.
+    parser.add_argument(
+        '--name',
+        help='Only check items with this name (repeating). '
+             'If not specified, all items are checked.',
+        dest='NAME',
+        action='append',
+        default=None,
+    )
+
     parser.add_argument(
         '--test',
         help='For unit tests. Needs "path-to-stdout-file,path-to-stderr-file,expected-retc".',
@@ -115,6 +152,13 @@ def main():
     except SystemExit:
         sys.exit(STATE_UNKNOWN)
 
+    # set default values for append parameters that were not specified
+    if args.IGNORE_REGEX is None:        # case 1: default to empty list
+        args.IGNORE_REGEX = []
+    if args.MODULE is None:              # case 2: default to non-empty list
+        args.MODULE = DEFAULT_MODULE
+    # args.NAME is not set here          # case 3: None means "check all"
+
     # fetch data
     if args.TEST is None:
         cmd = 'cat /etc/os-release'
@@ -138,6 +182,10 @@ def main():
 
     # analyze data
     title = 'Lorem ipsum'
+    if args.NAME is not None:
+        # case 3: user specified --name, so filter
+        if title not in args.NAME:
+            pass # in loops: continue
     if any(item.search(title) for item in compiled_ignore_regex):
         pass # in loops: continue
     value = str(lib.time.now())[-2:]

check-plugins/file-ownership/file-ownership

@@ -21,7 +21,7 @@ from lib.globals import (STATE_OK, STATE_UNKNOWN,  # pylint: disable=C0413
                           STATE_WARN)
 
 __author__ = 'Linuxfabrik GmbH, Zurich/Switzerland'
-__version__ = '2025100601'
+__version__ = '2026033101'
 
 DESCRIPTION = 'Checks the ownership (owner and group, both have to be names) of a list of files.'
 
@@ -85,7 +85,7 @@ def parse_args():
         help='File to be checked, in the format `owner:group,path` (repeatable).',
         action='append',
         dest='FILES',
-        default=DEFAULT_FILES,
+        default=None,
     )
 
     args, _ = parser.parse_known_args()
@@ -102,6 +102,10 @@ def main():
     except SystemExit:
         sys.exit(STATE_UNKNOWN)
 
+    # set default values for append parameters that were not specified
+    if args.FILES is None:
+        args.FILES = DEFAULT_FILES
+
     state = STATE_OK
     msg = ''
     cnt = 0