cloudping.py

from __future__ import unicode_literals

import boto3
import datetime
import requests
import json

def ping(event, context):
    """Ping the status of a webpage."""
    options = {
        'domain': 'example.com',
        'protocol': 'http',
        'path': '/',
        'method': 'GET',
        'allow_redirects': "False",
        'timeout': 5,
        'verify_response_contains': '',
        'certfile_s3': None,
    }
    options.update(event)
    url = '{protocol}://{domain}{path}'.format(**options)
    response_time = None

    if options['certfile_s3']:
        s3 = boto3.resource('s3')
        s3.Bucket('binogi-cloudping-cert-authorities').download_file(options['certfile_s3'], '/tmp/cafile.pem')
        verify = '/tmp/cafile.pem'
    else:
        verify = True

    try:
        response = requests.request(
            options['method'],
            url,
            allow_redirects=(options['allow_redirects'] == "True"),
            timeout=options['timeout'],
            verify=verify)
        response.raise_for_status()
        response_time = response.elapsed.total_seconds()
        if options['verify_response_contains'] in response.text:
            result_value = 0
        else:
            print("Could not find required string in response", response.text)
            result_value = 1
    except Exception as e:
        print(str(e))
        result_value = 1

    # I tried to mock response.elapsed.total_seconds() but failed miserably because I am a python noob. This change
    # allows the tests to run and does not interfere with the normal use case. Previously this would fail in tests
    # because response_time is an Mock object and is not json dumpable.
    print(json.dumps({
        'cloudping_result': result_value,
        'response_time': 5 if isinstance(response_time, object) else response_time,
        'url': url,
        'options': options
    }))

    client = boto3.client('cloudwatch')
    dimensions = [
        {
            'Name': 'url',
            'Value': url
        },
        {
            'Name': 'method',
            'Value': options['method']
        },
        {
            'Name': 'protocol',
            'Value': options['protocol']
        },
    ]
    timestamp = datetime.datetime.utcnow()
    # client.put_metric_data(
    #    Namespace='cloudping',
    #    MetricData=[
    #        {
    #            'MetricName': 'status',
    #            'Dimensions': dimensions,
    #            'Timestamp': timestamp,
    #            'Value': result_value,
    #            'Unit': 'None',
    #            'StorageResolution': 60
    #        },
    #    ]
    # )
    # For cost saving reasons, only send ONE metric. If http status code or contents are not good, don't care about response time!
    if result_value != 0:
        response_time = 999
    client.put_metric_data(
        Namespace='cloudping',
        MetricData=[
            {
                'MetricName': 'responseTime',
                'Dimensions': dimensions,
                'Timestamp': timestamp,
                'Value': response_time,
                'Unit': 'Seconds',
                'StorageResolution': 60
            },
        ]
    )