Python plugin for cachet that monitors an URL, verifying it's response status and latency. The frequency the URL is tested is configurable, along with the assertion applied to the request response.
This project is available at PyPI: https://pypi.python.org/pypi/cachet-url-monitor
endpoints:
- name: Google
url: http://www.google.com
method: GET
header:
SOME-HEADER: SOME-VALUE
timeout: 1 # seconds
expectation:
- type: HTTP_STATUS
status_range: 200-205
- type: LATENCY
threshold: 1
- type: REGEX
regex: ".*<body>.*"
allowed_fails: 0
component_id: 1
metric_id: 1
action:
- UPDATE_STATUS
public_incidents: true
latency_unit: ms
frequency: 5
- name: Amazon
url: http://www.amazon.com
method: GET
header:
SOME-HEADER: SOME-VALUE
timeout: 1 # seconds
expectation:
- type: HTTP_STATUS
status_range: 200-205
incident: MAJOR
- type: LATENCY
threshold: 1
- type: REGEX
regex: ".*<body>.*"
threshold: 10
allowed_fails: 0
component_id: 2
action:
- CREATE_INCIDENT
public_incidents: true
latency_unit: ms
frequency: 5
cachet:
api_url: http://status.cachethq.io/api/v1
token: mytoken- endpoints, the configuration about the URL/Urls that will be monitored.
- name, The name of the component. This is now mandatory (since 0.6.0) so we can distinguish the logs for each URL being monitored.
- url, the URL that is going to be monitored. mandatory
- method, the HTTP method that will be used by the monitor. mandatory
- header, client header passed to the request. Remove if you do not want to pass a header.
- timeout, how long we'll wait to consider the request failed. The unit of it is seconds. mandatory
- expectation, the list of expectations set for the URL. mandatory
- HTTP_STATUS, we will verify if the response status code falls into the expected range. Please keep in mind the range is inclusive on the first number and exclusive on the second number. If just one value is specified, it will default to only the given value, for example
200will be converted to200-201. - LATENCY, we measure how long the request took to get a response and fail if it's above the threshold. The unit is in seconds.
- REGEX, we verify if the response body matches the given regex.
- HTTP_STATUS, we will verify if the response status code falls into the expected range. Please keep in mind the range is inclusive on the first number and exclusive on the second number. If just one value is specified, it will default to only the given value, for example
- allowed_fails, create incident/update component status only after specified amount of failed connection trials.
- component_id, the id of the component we're monitoring. This will be used to update the status of the component. mandatory
- metric_id, this will be used to store the latency of the API. If this is not set, it will be ignored.
- action, the action to be done when one of the expectations fails. This is optional and if left blank, nothing will be done to the component.
- CREATE_INCIDENT, we will create an incident when the expectation fails.
- UPDATE_STATUS, updates the component status.
- PUSH_METRICS, uploads response latency metrics.
- public_incidents, boolean to decide if created incidents should be visible to everyone or only to logged in users. Important only if
CREATE_INCIDENTorUPDATE_STATUSare set. - latency_unit, the latency unit used when reporting the metrics. It will automatically convert to the specified unit. It's not mandatory and it will default to seconds. Available units:
ms,s,m,h. - frequency, how often we'll send a request to the given URL. The unit is in seconds.
- cachet, this is the settings for our cachet server.
- api_url, the cachet API endpoint. mandatory
- token, the API token. mandatory
Each expectation has their own default incident status. It can be overridden by setting the incident property to any of the following values:
PARTIALMAJORPERFORMANCE
By choosing any of the aforementioned statuses, it will let you control the kind of incident it should be considered. These are the default incident status for each expectation type:
| Expectation | Incident status |
|---|---|
| HTTP_STATUS | PARTIAL |
| LATENCY | PERFORMANCE |
| REGEX | PARTIAL |
The application should be installed using virtualenv, through the following command:
$ git clone https://github.com/mtakaki/cachet-url-monitor.git
$ virtualenv cachet-url-monitor
$ cd cachet-url-monitor
$ source bin/activate
$ pip install -r requirements.txt
$ python3 setup.py installTo start the agent:
$ python3 cachet_url_monitor/scheduler.py config.ymlYou can run the agent in docker, so you won't need to worry about installing python, virtualenv, or any other dependency into your OS. The Dockerfile is already checked in and it's ready to be used.
You have two choices, checking this repo out and building the docker image or it can be pulled directly from dockerhub. You will need to create your own custom config.yml file and run (it will pull latest):
$ docker pull mtakaki/cachet-url-monitor
$ docker run --rm -it -v "$PWD":/usr/src/app/config/ mtakaki/cachet-url-monitorIf you're going to use a file with a name other than config.yml, you will need to map the local file, like this:
$ docker run --rm -it -v "$PWD"/my_config.yml:/usr/src/app/config/config.yml:ro mtakaki/cachet-url-monitorIn order to expedite the creation of your configuration file, you can use the client to automatically scrape the CachetHQ instance and spit out a YAML file. It can be used like this:
$ python cachet_url_monitor/client.py http://localhost/api/v1 my-token test.ymlOr from docker (you will end up with a test.yml in your $PWD/tmp folder):
$ docker run --rm -it -v $PWD/tmp:/home/tmp/ mtakaki/cachet-url-monitor python3.7 ./cachet_url_monitor/client.py http://localhost/api/v1 my-token /home/tmp/test.ymlThe arguments are:
- URL, the CachetHQ API URL, so that means appending
/api/v1to your hostname. - token, the token that has access to your CachetHQ instance.
- filename, the file where it should write the configuration.
Because we can't predict what expectations will be needed, it will default to these behavior:
- Verify a [200-300[ HTTP status range.
- If status fail, make the incident major and public.
- Frequency of 30 seconds.
GETrequest.- Timeout of 1s.
- We'll read the
linkfield from the components and use it as the URL.
If it's throwing the following exception:
raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='redacted', port=443): Max retries exceeded with url: /api/v1/components/19 (Caused by SSLError(SSLError(1, u'[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:579)'),))It can be resolved by seting the CA bundle environment variable REQUESTS_CA_BUNDLE pointing at your certificate file. It can either be set in your python environment, before running this tool, or in your docker container.