かなり昔に Mackarel で h2o のステータス取得しようとして書いたやつ。公式があるならそっちを使ったほうがいいとは思う

mackerel-plugin-h2o.py

#!/usr/bin/env python3
import os
import datetime
import urllib.request
import json


def fetch_h2o_status(status_url="http://localhost/server-status"):

    req = urllib.request.Request(url='{0}/json'.format(status_url))

    with urllib.request.urlopen(req) as res:
        result = json.loads(res.read().decode('utf-8'))

    result.pop('requests')
    return result


def show_metadata_for_mackerel():

    metadata = {
        'graphs': {
            'h2o.body-time': {
                'label': 'H2O status body time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
             },
            'h2o.connect-time': {
                'label': 'H2O status connect time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.connections': {
                'label': 'H2O status connections',
                'unit': 'integer',
                'metric': [
                    {'name':'current', 'label': 'current connections'},
                    {'name':'max', 'label': 'max connections'}
                ]
            },
            'h2o.duration': {
                'label': 'H2O status duration',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.body-time': {
                'label': 'H2O status body time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.http2': {
                'label': 'H2O status http2',
                'unit': 'integer',
                'metric': [
                    {'name':'read-closed', 'label': None},
                    {'name':'write-closed', 'label': None}
                ]
            },
            'h2o.http2-errors': {
                'label': 'H2O status http2 error',
                'unit': 'integer',
                'metric': [
                    {'name': 'cancel', 'label': None},
                    {'name': 'compression', 'label': None},
                    {'name': 'connect', 'label': None},
                    {'name': 'enhance-your-calm', 'label': None},
                    {'name': 'flow-control', 'label': None},
                    {'name': 'frame-size', 'label': None},
                    {'name': 'inadequate-security', 'label': None},
                    {'name': 'internal', 'label': None},
                    {'name': 'protocol', 'label': None},
                    {'name': 'refused-stream', 'label': None},
                    {'name': 'settings-timeout', 'label': None},
                    {'name': 'stream-closed', 'label': None},
                ]
            },
            'h2o.listeners': {
                'label': 'H2O status listeners',
                'unit': 'integer',
                'metric': [
                    {'name': 'listeners', 'label': None}
                ]
            },
            'h2o.num-sessions': {
                'label': 'H2O status num-sessions',
                'unit': 'integer',
                'metric': [
                    {'name': 'num-sessions', 'label': None}
                ]
             },
            'h2o.process-time': {
                'label': 'H2O status process-time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.request-total-time': {
                'label': 'H2O status request-total-time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.response-time': {
                'label': 'H2O status response-time',
                'unit': 'integer',
                'metric': [
                    {'name':'0', 'label': None },
                    {'name':'25', 'label': None },
                    {'name':'50', 'label': None },
                    {'name':'75', 'label': None },
                    {'name':'99', 'label': None },
                ]
            },
            'h2o.status-errors': {
                'label': 'H2O status status-error',
                'unit': 'integer',
                'metric': [
                    {'name': '400', 'label': None},
                    {'name': '403', 'label': None},
                    {'name': '404', 'label': None},
                    {'name': '405', 'label': None},
                    {'name': '416', 'label': None},
                    {'name': '417', 'label': None},
                    {'name': '500', 'label': None},
                    {'name': '502', 'label': None},
                    {'name': '503', 'label': None},
                ]
            },
            'h2o.uptime': {
                'label': 'H2O status uptime',
                'unit': 'integer',
                'metric': [
                    {'name': 'current', 'label': None}
                ]
            },
            'h2o.worker-threads': {
                'label': 'H2O status worker-threads',
                'unit': 'integer',
                'metric': [
                    {'name': 'worker-threads', 'label': None}
                ]
            },
        }
    }
    print(json.dumps(metadata, indent=2)) 

def migrate_h2o_status(h2o_status):

    result = []
    key_prefix = 'h2o'

    for i in ['openssl-version', 'restart-time', 'server-version', 'generation']:
        h2o_status.pop(i)

    current_time = datetime.datetime.strptime(h2o_status.pop('current-time'), '%d/%b/%Y:%H:%M:%S %z')
    current_time_unix = int(current_time.timestamp())

    for key, value in h2o_status.items():
        if 'body-time' in key:
            key = key.replace('body-time-', 'body-time.')
        elif 'connect-time' in key:
            key = key.replace('connect-time-', 'connect-time.')
        elif 'duration' in key:
            key = key.replace('duration-', 'duration.')
        elif 'header-time' in key:
            key = key.replace('header-time-', 'header-time.')
        elif 'timss-time' in key:
            key = key.replace('process-time-', 'process-time.')
        elif 'request-total-time' in key:
            key = key.replace('request-total-time-', 'request-total-time.')
        elif 'response-time' in key:
            key = key.replace('response-time-', 'response-time.')
        elif 'connection' in key:
            if key == 'connections':
                key = '{0}.current'.format(key)
            elif key == 'max-connections':
                key = 'connections.max'
        elif 'uptime' in key:
            key = 'uptime.current'

        result.append(('{0}.{1}'.format(key_prefix, key), str(value), str(current_time_unix)))

    return result


def output_tsv(h2o_status):
    for i in h2o_status:
        print('\t'.join(i))   
    

def main():

    if os.environ.get('MACKEREL_AGENT_PLUGIN_META'):
        show_metadata_for_mackerel()
    else:
        raw_h2o_status = fetch_h2o_status()
        h2o_status = migrate_h2o_status(raw_h2o_status)
        output_tsv(h2o_status)


if __name__ == '__main__':
    main()