simono41/prometheus-ssh-exporter
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Handles short sessions

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Can now handle sessions of duration < FETCH_INTERVAL
This commit is contained in:
Florian Rupp 2023-04-21 18:27:28 +02:00
parent e9a0742b6e
commit a72844c3b2
2 changed files with 67 additions and 23 deletions
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135
prometheus-ssh-exporter.py
View file

@ -2,11 +2,21 @@ import prometheus_client
import time
import argparse
import utmp
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler, FileModifiedEvent
# These defaults can be overwritten by command line arguments
SERVER_HOST = '0.0.0.0'
SERVER_PORT = 9999
FETCH_INTERVAL = 15
WATCHFILE = '/var/run/utmp'
class FileOpenedHandler(FileSystemEventHandler):
def on_modified(self, event):
if not event.is_directory and isinstance(event, FileModifiedEvent) and event.src_path == WATCHFILE:
handle_sessions_changed()
class Session:
@ -53,54 +63,13 @@ def get_utmp_data() -> list[Session]:
def parse_arguments() -> None:
global FETCH_INTERVAL, SERVER_PORT, SERVER_HOST
parser = argparse.ArgumentParser(
prog='python prometheus-ssh-exporter.py',
description='Prometheus exporter for info about SSH sessions')
parser.add_argument('-H', '--host', type=str,
default='0.0.0.0', help='Hostname to bind to')
parser.add_argument('-p', '--port', type=int, default=9999,
help='Port for the server to listen to')
parser.add_argument('-i', '--interval', type=int, default=15,
help='Interval in seconds to fetch SSH sessions data')
args = parser.parse_args()
FETCH_INTERVAL = args.interval
SERVER_PORT = args.port
SERVER_HOST = args.host
if __name__ == '__main__':
def handle_sessions_changed() -> None:
"""
This program exports the number of SSH sessions as a metric "ssh_num_sessions" for prometheus.
It applies a label to each increment or decrement of that number, containing the remote IP address.
That way we can filter by the remote IP in Grafana, getting the number of SSH sessions by IP address,
or sum them up to get the total number of sessions.
This function fetches the current list of SSH sessions and compares it to the previous list of SSH sessions.
If the number of sessions has changed, it increments or decrements the gauge_num_sessions metric
and updates the session_data and num_sessions variables.
"""
parse_arguments()
# Start up the server to expose the metrics.
prometheus_client.start_http_server(SERVER_PORT)
print("Started metrics server bound to {}:{}".format(SERVER_HOST, SERVER_PORT))
gauge_num_sessions = prometheus_client.Gauge(
'ssh_num_sessions', 'Number of SSH sessions', ['remote_ip'])
session_data = get_utmp_data()
num_sessions = len(session_data)
# Initial metrics
print("Active sessions at startup:")
for session in session_data:
gauge_num_sessions.labels(remote_ip=session.from_).inc()
print("Initial connection: {}".format(session.from_))
# Generate some requests.
print("Looking for SSH connection changes at interval {}".format(FETCH_INTERVAL))
while True:
global session_data, num_sessions, gauge_num_sessions, old_session_data, old_num_sessions
old_session_data = session_data
old_num_sessions = len(old_session_data)
@ -120,4 +89,78 @@ if __name__ == '__main__':
print("Session disconnected: %s" % maybe_old_session.from_)
gauge_num_sessions.labels(remote_ip=maybe_old_session.from_).dec()
def parse_arguments() -> None:
global FETCH_INTERVAL, SERVER_PORT, SERVER_HOST, WATCHFILE
parser = argparse.ArgumentParser(
prog='python prometheus-ssh-exporter.py',
description='Prometheus exporter for info about SSH sessions')
parser.add_argument('-H', '--host', type=str,
default='0.0.0.0', help='Hostname to bind to')
parser.add_argument('-p', '--port', type=int, default=9999,
help='Port for the server to listen to')
parser.add_argument('-i', '--interval', type=int, default=15,
help='Interval in seconds to fetch SSH sessions data')
parser.add_argument('-f', '--file', type=str, default='/var/run/utmp',
help='File that changes every time a new SSH session is opened or closed')
args = parser.parse_args()
FETCH_INTERVAL = args.interval
SERVER_PORT = args.port
SERVER_HOST = args.host
WATCHFILE = args.file
if __name__ == '__main__':
"""
This program exports the number of SSH sessions as a metric "ssh_num_sessions" for prometheus.
It applies a label to each increment or decrement of that number, containing the remote IP address.
That way we can filter by the remote IP in Grafana, getting the number of SSH sessions by IP address,
or sum them up to get the total number of sessions.
"""
parse_arguments()
# Start up the server to expose the metrics.
prometheus_client.start_http_server(SERVER_PORT)
print("Started metrics server bound to {}:{}".format(SERVER_HOST, SERVER_PORT))
gauge_num_sessions = prometheus_client.Gauge(
'ssh_num_sessions', 'Number of SSH sessions', ['remote_ip'])
# session_data contains the current list of sessions
session_data = get_utmp_data()
num_sessions = len(session_data)
# Initial metrics
for session in session_data:
gauge_num_sessions.labels(remote_ip=session.from_).inc()
print("Initial connection: {}".format(session.from_))
"""
Start the watchdog to monitor the WATCHDOG file for changes.
This is used to immediately look for changes in the SSH sessions when a new session is opened or closed
to prevent missing any sessions that lasted less than the FETCH_INTERVAL.
"""
event_handler = FileOpenedHandler()
observer = Observer()
observer.schedule(event_handler, path=WATCHFILE, recursive=False)
observer.start()
# Generate some requests.
print("Looking for SSH connection changes at interval {}".format(FETCH_INTERVAL))
try:
while True:
# Keep looking for changes in the SSH sessions in case the watchdog missed something
handle_sessions_changed()
time.sleep(FETCH_INTERVAL)
except KeyboardInterrupt:
print("Manual interrupt...")
observer.stop()
observer.join()

1
requirements.txt
View file

@ -1,2 +1,3 @@
prometheus_client==0.16.0
utmp==21.10.0
watchdog==3.0.0