138 lines
3.4 KiB
Python
138 lines
3.4 KiB
Python
#!/usr/bin/env python3
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"""
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Module to act as a Prometheus Exporter for Docker containers with a
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healthcheck configured
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"""
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import argparse
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import os.path
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import sys
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from http.server import HTTPServer
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import docker
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from prometheus_client import (
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CollectorRegistry,
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Gauge,
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generate_latest,
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MetricsHandler,
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)
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LISTEN_PORT = 8080
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HEALTHY_STR = 'healthy'
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class HTTPHandler(MetricsHandler):
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"""
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Class to encompass the requirements of a Prometheus Exporter
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for Docker containers with a healthcheck configured
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"""
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def __init__(self, *args, **kwargs):
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self.docker_api = docker.APIClient()
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self.docker_client = docker.from_env()
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super().__init__(*args, **kwargs)
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# Override built-in method
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# pylint: disable=invalid-name
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def do_GET(self):
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"""
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Method to handle GET requests
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"""
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if self.path == '/metrics':
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self._metrics()
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if self.path == '/healthcheck':
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if not healthy():
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print('ERROR: Check requirements')
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self._respond(500, 'ERR')
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self._respond(200, 'OK')
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def _respond(self, status, message):
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"""
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Method to output a simple HTTP status and string to the client
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"""
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self.send_response(int(status) or 500)
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self.end_headers()
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self.wfile.write(bytes(str(message).encode()))
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def _metrics(self):
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"""
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Method to handle the request for metrics
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"""
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if not healthy:
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print('ERROR: Check requirements')
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self._respond(500, 'Server not configured correctly')
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return
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registry = CollectorRegistry()
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gauge = Gauge(
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'container_inspect_state_health_status',
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"Container's healthcheck value (binary)",
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labelnames=['id', 'name', 'value'],
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registry=registry
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)
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for container in self.docker_client.containers.list():
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data = self.docker_api.inspect_container(container.id)
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try:
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health_str = data["State"]["Health"]["Status"]
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label_values = [
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container.id,
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container.name,
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health_str,
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]
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except KeyError:
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pass
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else:
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gauge.labels(*label_values).set(int(health_str == HEALTHY_STR))
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self._respond(200, generate_latest(registry).decode())
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def healthy():
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"""
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Simple funtion to return if all the requirements are met
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"""
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return all([
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os.path.exists('/var/run/docker.sock'),
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])
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if __name__ == '__main__':
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def cli_parse():
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"""
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Function to parse the CLI
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"""
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parser = argparse.ArgumentParser()
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parser.add_argument(
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'-H', '--healthcheck',
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action='store_true',
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help='Simply exit with 0 for healthy or 1 when unhealthy',
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)
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return parser.parse_args()
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def main():
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"""
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main()
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"""
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args = cli_parse()
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if args.healthcheck:
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# Invert the sense of 'healthy' for Unix CLI usage
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return not healthy()
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print(f'Starting web server on port {LISTEN_PORT}')
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try:
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HTTPServer(('', LISTEN_PORT), HTTPHandler).serve_forever()
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except KeyboardInterrupt:
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print('Exiting')
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return 0
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sys.exit(main())
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