From 74454c341a57aab66151b9ef2488eb72a306c002 Mon Sep 17 00:00:00 2001
From: zsdc <taras@vyos.io>
Date: Mon, 6 Jun 2022 21:33:17 +0300
Subject: event-handler: T3083: Optimized event-handler
* Removed dynamic generating for systemd unit
* Optimized configuration file deleting process
* Added exceptions handlers to event-handler script to protect service
from most obvious potential troubles
* Improved logging
* Moved pattern compilation outside a messages loop to avoid extra operations
* Added signal handlers for proper systemd integration
---
src/system/vyos-event-handler.py | 120 +++++++++++++++++++++++++++++++++++++++
1 file changed, 120 insertions(+)
create mode 100755 src/system/vyos-event-handler.py
(limited to 'src/system')
diff --git a/src/system/vyos-event-handler.py b/src/system/vyos-event-handler.py
new file mode 100755
index 000000000..f4b793dbe
--- /dev/null
+++ b/src/system/vyos-event-handler.py
@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 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 argparse
+import select
+import re
+import json
+from os import getpid
+from pathlib import Path
+from signal import signal, SIGTERM, SIGINT
+from systemd import journal
+from sys import exit
+from vyos.util import call
+
+# Identify this script
+my_pid = getpid()
+my_name = Path(__file__).stem
+
+
+# handle termination signal
+def handle_signal(signal_type, frame):
+ if signal_type == SIGTERM:
+ journal.send('Received SIGTERM signal, stopping normally',
+ SYSLOG_IDENTIFIER=my_name)
+ if signal_type == SIGINT:
+ journal.send('Received SIGINT signal, stopping normally',
+ SYSLOG_IDENTIFIER=my_name)
+ exit(0)
+
+
+# Execute script safely
+def script_run(pattern: str, script_path: str) -> None:
+ try:
+ call(script_path)
+ journal.send(
+ f'Pattern found: "{pattern}", script executed: "{script_path}"',
+ SYSLOG_IDENTIFIER=my_name)
+ except Exception as err:
+ journal.send(
+ f'Pattern found: "{pattern}", failed to execute script "{script_path}": {err}',
+ SYSLOG_IDENTIFIER=my_name)
+
+
+# iterate trough regexp items
+def analyze_message(message: str, regex_patterns: dict) -> None:
+ for pattern_compiled, pattern_config in regex_patterns.items():
+ if pattern_compiled.match(message):
+ script_run(pattern_config['pattern_raw'],
+ pattern_config['pattern_script'])
+
+
+if __name__ == '__main__':
+ # Parse command arguments and get config
+ parser = argparse.ArgumentParser()
+ parser.add_argument('-c',
+ '--config',
+ action='store',
+ help='Path to even-handler configuration',
+ required=True,
+ type=Path)
+
+ args = parser.parse_args()
+ try:
+ config_path = Path(args.config)
+ config = json.loads(config_path.read_text())
+ except Exception as err:
+ print(
+ f'Configuration file "{config_path}" does not exist or malformed: {err}'
+ )
+ exit(1)
+
+ # Prepare for proper exitting
+ signal(SIGTERM, handle_signal)
+ signal(SIGINT, handle_signal)
+
+ # Set up journal connection
+ data = journal.Reader()
+ data.seek_tail()
+ data.get_previous()
+ p = select.poll()
+ p.register(data, data.get_events())
+
+ # Prepare compiled regex objects
+ patterns = {}
+ for name, event_config in config.items():
+ pattern_raw = f'{event_config["pattern"]}'
+ pattern_compiled = re.compile(rf'{event_config["pattern"]}')
+ pattern_config = {
+ pattern_compiled: {
+ 'pattern_raw': pattern_raw,
+ 'pattern_script': event_config['script']
+ }
+ }
+ patterns.update(pattern_config)
+
+ journal.send(f'Started with configuration: {config}',
+ SYSLOG_IDENTIFIER=my_name)
+
+ while p.poll():
+ if data.process() != journal.APPEND:
+ continue
+ for entry in data:
+ message = entry['MESSAGE']
+ pid = entry['_PID']
+ # Skip empty messages and messages from this process
+ if message and pid != my_pid:
+ analyze_message(message, patterns)
--
cgit v1.2.3
From 06c0d2f2f9f4b9c97eb9868df166d787ca367ee7 Mon Sep 17 00:00:00 2001
From: zsdc <taras@vyos.io>
Date: Tue, 7 Jun 2022 14:34:49 +0300
Subject: event-handler: T3083: Extended event-handler features
* Added the ability to filter by a syslog identifier
* Added the ability to pass arguments to a script
* Added the ability to pass preconfigured environment variables to a script
* A message that triggered a script is now passed in the `message` variable and
can be used in a script
* Replaced `call()` to `run()`, since stdout are not need to be printed
---
interface-definitions/service-event-handler.xml.in | 18 +++-
src/conf_mode/service_event_handler.py | 13 ++-
src/system/vyos-event-handler.py | 110 ++++++++++++++-------
3 files changed, 100 insertions(+), 41 deletions(-)
(limited to 'src/system')
diff --git a/interface-definitions/service-event-handler.xml.in b/interface-definitions/service-event-handler.xml.in
index 3e96013c7..ed6d41d1b 100644
--- a/interface-definitions/service-event-handler.xml.in
+++ b/interface-definitions/service-event-handler.xml.in
@@ -7,11 +7,23 @@
<help>Event handler name</help>
</properties>
<children>
- <leafNode name="pattern">
+ <node name="filter">
<properties>
- <help>Match pattern (regex)</help>
+ <help>Logs filter settings</help>
</properties>
- </leafNode>
+ <children>
+ <leafNode name="pattern">
+ <properties>
+ <help>Match pattern (regex)</help>
+ </properties>
+ </leafNode>
+ <leafNode name="syslog-identifier">
+ <properties>
+ <help>Identifier of a process in syslog (string)</help>
+ </properties>
+ </leafNode>
+ </children>
+ </node>
<node name="script">
<properties>
<help>Event handler script file</help>
diff --git a/src/conf_mode/service_event_handler.py b/src/conf_mode/service_event_handler.py
index cf4aba49b..bb12da11d 100755
--- a/src/conf_mode/service_event_handler.py
+++ b/src/conf_mode/service_event_handler.py
@@ -18,7 +18,7 @@ import json
from pathlib import Path
from vyos.config import Config
-from vyos.util import call
+from vyos.util import call, dict_search
from vyos import ConfigError
from vyos import airbag
@@ -48,9 +48,16 @@ def verify(config):
return None
for name, event_config in config.items():
- if 'pattern' not in event_config or 'script' not in event_config:
+ if not dict_search('filter.pattern', event_config) or not dict_search(
+ 'script.path', event_config):
raise ConfigError(
- 'Event-handler: both pattern and script items are mandatory!')
+ 'Event-handler: both pattern and script path items are mandatory'
+ )
+
+ if dict_search('script.environment.message', event_config):
+ raise ConfigError(
+ 'Event-handler: "message" environment variable is reserved for log message text'
+ )
def generate(config):
diff --git a/src/system/vyos-event-handler.py b/src/system/vyos-event-handler.py
index f4b793dbe..691f674b2 100755
--- a/src/system/vyos-event-handler.py
+++ b/src/system/vyos-event-handler.py
@@ -18,12 +18,12 @@ import argparse
import select
import re
import json
-from os import getpid
+from os import getpid, environ
from pathlib import Path
from signal import signal, SIGTERM, SIGINT
from systemd import journal
from sys import exit
-from vyos.util import call
+from vyos.util import run, dict_search
# Identify this script
my_pid = getpid()
@@ -41,25 +41,72 @@ def handle_signal(signal_type, frame):
exit(0)
-# Execute script safely
-def script_run(pattern: str, script_path: str) -> None:
- try:
- call(script_path)
- journal.send(
- f'Pattern found: "{pattern}", script executed: "{script_path}"',
- SYSLOG_IDENTIFIER=my_name)
- except Exception as err:
- journal.send(
- f'Pattern found: "{pattern}", failed to execute script "{script_path}": {err}',
- SYSLOG_IDENTIFIER=my_name)
-
-
-# iterate trough regexp items
-def analyze_message(message: str, regex_patterns: dict) -> None:
- for pattern_compiled, pattern_config in regex_patterns.items():
- if pattern_compiled.match(message):
- script_run(pattern_config['pattern_raw'],
- pattern_config['pattern_script'])
+# Class for analyzing and process messages
+class Analyzer:
+ # Initialize settings
+ def __init__(self, config: dict) -> None:
+ self.config = {}
+ # Prepare compiled regex objects
+ for event_id, event_config in config.items():
+ script = dict_search('script.path', event_config)
+ # Check for arguments
+ if dict_search('script.arguments', event_config):
+ script_arguments = dict_search('script.arguments', event_config)
+ script = f'{script} {script_arguments}'
+ # Prepare environment
+ environment = environ
+ # Check for additional environment options
+ if dict_search('script.environment', event_config):
+ for env_variable, env_value in dict_search(
+ 'script.environment', event_config).items():
+ environment[env_variable] = env_value.get('value')
+ # Create final config dictionary
+ pattern_raw = event_config['filter']['pattern']
+ pattern_compiled = re.compile(
+ rf'{event_config["filter"]["pattern"]}')
+ pattern_config = {
+ pattern_compiled: {
+ 'pattern_raw':
+ pattern_raw,
+ 'syslog_id':
+ dict_search('filter.syslog_identifier', event_config),
+ 'pattern_script': {
+ 'path': script,
+ 'environment': environment
+ }
+ }
+ }
+ self.config.update(pattern_config)
+
+ # Execute script safely
+ def script_run(self, pattern: str, script_path: str,
+ script_env: dict) -> None:
+ try:
+ run(script_path, env=script_env)
+ journal.send(
+ f'Pattern found: "{pattern}", script executed: "{script_path}"',
+ SYSLOG_IDENTIFIER=my_name)
+ except Exception as err:
+ journal.send(
+ f'Pattern found: "{pattern}", failed to execute script "{script_path}": {err}',
+ SYSLOG_IDENTIFIER=my_name)
+
+ # Analyze a message
+ def process_message(self, message: dict) -> None:
+ for pattern_compiled, pattern_config in self.config.items():
+ # Check if syslog id is presented in config and matches
+ syslog_id = pattern_config.get('syslog_id')
+ if syslog_id and message['SYSLOG_IDENTIFIER'] != syslog_id:
+ continue
+ if pattern_compiled.fullmatch(message['MESSAGE']):
+ # Add message to environment variables
+ pattern_config['pattern_script']['environment'][
+ 'message'] = message['MESSAGE']
+ # Run script
+ self.script_run(
+ pattern=pattern_config['pattern_raw'],
+ script_path=pattern_config['pattern_script']['path'],
+ script_env=pattern_config['pattern_script']['environment'])
if __name__ == '__main__':
@@ -76,6 +123,8 @@ if __name__ == '__main__':
try:
config_path = Path(args.config)
config = json.loads(config_path.read_text())
+ # Create an object for analazyng messages
+ analyzer = Analyzer(config)
except Exception as err:
print(
f'Configuration file "{config_path}" does not exist or malformed: {err}'
@@ -93,19 +142,6 @@ if __name__ == '__main__':
p = select.poll()
p.register(data, data.get_events())
- # Prepare compiled regex objects
- patterns = {}
- for name, event_config in config.items():
- pattern_raw = f'{event_config["pattern"]}'
- pattern_compiled = re.compile(rf'{event_config["pattern"]}')
- pattern_config = {
- pattern_compiled: {
- 'pattern_raw': pattern_raw,
- 'pattern_script': event_config['script']
- }
- }
- patterns.update(pattern_config)
-
journal.send(f'Started with configuration: {config}',
SYSLOG_IDENTIFIER=my_name)
@@ -117,4 +153,8 @@ if __name__ == '__main__':
pid = entry['_PID']
# Skip empty messages and messages from this process
if message and pid != my_pid:
- analyze_message(message, patterns)
+ try:
+ analyzer.process_message(entry)
+ except Exception as err:
+ journal.send(f'Unable to process message: {err}',
+ SYSLOG_IDENTIFIER=my_name)
--
cgit v1.2.3