healthchecks

healthchecks is a watchdog for your cron jobs. It's a web server that listens for pings from your cron jobs, plus a web interface.

It is live here: http://healthchecks.io/

The building blocks are:

Python 3
Django 2
PostgreSQL or MySQL

Setting Up for Development

These are instructions for setting up healthchecks Django app in development environment.

prepare directory for project code and virtualenv:
```
  $ mkdir -p ~/webapps
  $ cd ~/webapps
```
prepare virtual environment (with virtualenv you get pip, we'll use it soon to install requirements):
```
  $ virtualenv --python=python3 hc-venv
  $ source hc-venv/bin/activate
```

check out project code:

  $ git clone https://github.com/healthchecks/healthchecks.git

install requirements (Django, ...) into virtualenv:

  $ pip install -r healthchecks/requirements.txt

healthchecks is configured to use a SQLite database by default. To use PostgreSQL or MySQL database, create and edit hc/local_settings.py file. There is a template you can copy and edit as needed:
```
  $ cd ~/webapps/healthchecks
  $ cp hc/local_settings.py.example hc/local_settings.py
```

create database tables and the superuser account:

  $ cd ~/webapps/healthchecks
  $ ./manage.py migrate
  $ ./manage.py createsuperuser

run development server:
```
  $ ./manage.py runserver
```

The site should now be running at http://localhost:8080 To log into Django administration site as a super user, visit http://localhost:8080/admin

Configuration

Site configuration is kept in hc/settings.py. Additional configuration is loaded from hc/local_settings.py file, if it exists. You can create this file (should be right next to settings.py in the filesystem) and override settings as needed.

Some useful settings keys to override are:

SITE_ROOT is used to build fully qualified URLs for pings, and for use in emails and notifications. Example:

SITE_ROOT = "https://my-monitoring-project.com"

SITE_NAME has the default value of "Mychecks" and is used throughout the templates. Replace it with your own name to personalize your installation. Example:

SITE_NAME = "My Monitoring Project"

REGISTRATION_OPEN controls whether site visitors can create new accounts. Set it to False if you are setting up a private healthchecks instance, but it needs to be publicly accessible (so, for example, your cloud services can send pings).

If you close new user registration, you can still selectively invite users to your team account.

Database Configuration

Database configuration is stored in hc/settings.py and can be overriden in hc/local_settings.py. The default database engine is SQLite. To use PostgreSQL, create hc/local_settings.py if it does not exist, and put the following in it, changing it as neccessary:

DATABASES = {
    'default': {
        'ENGINE':   'django.db.backends.postgresql',
        'NAME':     'your-database-name-here',
        'USER':     'your-database-user-here',
        'PASSWORD': 'your-database-password-here',
        'TEST': {'CHARSET': 'UTF8'}
    }
}

For MySQL:

DATABASES = {
    'default': {
        'ENGINE':   'django.db.backends.mysql',
        'NAME':     'your-database-name-here',
        'USER':     'your-database-user-here',
        'PASSWORD': 'your-database-password-here',
        'TEST': {'CHARSET': 'UTF8'}
    }
}

You can also use hc/local_settings.py to read database configuration from environment variables like so:

import os

DATABASES = {
    'default': {
        'ENGINE':   os.environ['DB_ENGINE'],
        'NAME':     os.environ['DB_NAME'],
        'USER':     os.environ['DB_USER'],
        'PASSWORD': os.environ['DB_PASSWORD'],
        'TEST': {'CHARSET': 'UTF8'}
    }
}

Sending Emails

healthchecks must be able to send email messages, so it can send out login links and alerts to users. Put your SMTP server configuration in hc/local_settings.py like so:

EMAIL_HOST = "your-smtp-server-here.com"
EMAIL_PORT = 587
EMAIL_HOST_USER = "username"
EMAIL_HOST_PASSWORD = "password"
EMAIL_USE_TLS = True

For more information, have a look at Django documentation, Sending Email section.

Sending Status Notifications

healtchecks comes with a sendalerts management command, which continuously polls database for any checks changing state, and sends out notifications as needed. Within an activated virtualenv, you can manually run the sendalerts command like so:

$ ./manage.py sendalerts

In a production setup, you will want to run this command from a process manager like supervisor or systemd.

Database Cleanup

With time and use the healthchecks database will grow in size. You may decide to prune old data: inactive user accounts, old checks not assigned to users, records of outgoing email messages and records of received pings. There are separate Django management commands for each task:

Remove old records from api_ping table. For each check, keep 100 most recent pings:
```
$ ./manage.py prunepings
```
Remove checks older than 2 hours that are not assigned to users. Such checks are by-products of random visitors and robots loading the welcome page and never setting up an account:
```
$ ./manage.py prunechecks
```
Remove old records of sent notifications. For each check, remove notifications that are older than the oldest stored ping for same check.
```
$ ./manage.py prunenotifications
```
Remove user accounts that match either of these conditions:
Account was created more than 6 months ago, and user has never logged in. These can happen when user enters invalid email address when signing up.
Last login was more than 6 months ago, and the account has no checks. Assume the user doesn't intend to use the account any more and would probably want it removed.
```
$ ./manage.py pruneusers
```

When you first try these commands on your data, it is a good idea to test them on a copy of your database, not on the live database right away. In a production setup, you should also have regular, automated database backups set up.

Integrations

Discord

To enable Discord integration, you will need to:

register a new application on https://discordapp.com/developers/applications/me
add a redirect URI to your Discord application. The URI format is SITE_ROOT/integrations/add_discord/. For example, if you are running a development server on localhost:8000 then the redirect URI would be http://localhost:8000/integrations/add_discord/
Look up your Discord app's Client ID and Client Secret. Add them to your hc/local_settings.py file as DISCORD_CLIENT_ID and DISCORD_CLIENT_SECRET fields.

Pushover

To enable Pushover integration, you will need to:

register a new application on https://pushover.net/apps/build
enable subscriptions in your application and make sure to enable the URL subscription type
add the application token and subscription URL to hc/local_settings.py, as PUSHOVER_API_TOKEN and PUSHOVER_SUBSCRIPTION_URL

Create a Telegram bot by talking to the BotFather. Set the bot's name, description, user picture, and add a "/start" command.
After creating the bot you will have the bot's name and token. Add them to your hc/local_settings.py file as TELEGRAM_BOT_NAME and TELEGRAM_TOKEN fields.
Run settelegramwebhook management command. This command tells Telegram where to forward channel messages by invoking Telegram's setWebhook API call:
```
$ ./manage.py settelegramwebhook
Done, Telegram's webhook set to: https://my-monitoring-project.com/integrations/telegram/bot/
```

For this to work, your SITE_ROOT needs to be correct and use "https://" scheme.

zeesattarny/healthchecks