Website Health Check Script with Slack Webhooks

1. How to start?

1. Clone repo where ever you can run script frequently

2. Create venv install requirements.txt

3. Get your slack webhook url

4. Prepare your configuration.json

5. Run main.py --test (You should get hello message on slack)

   

6. Prepare script runner (I use cron)

7. I hope you enjoy!

You can also see logs section.

2. Get slack webhook url

1. Go to https://api.slack.com/messaging/webhooks
2. Click Create your Slack app
3. Click Create new app and follow the steps
4. In left panel slack app go to Incoming webhooks

6. Turn On Activate Incoming Webhooks
7. Add New Webhook to Workspace
8. After choose channel you can copy your url

3. Create your configuration.json file

slack_webhook_url is required in configuration.json. Put here your url

 "slack_webhook_url": "https://hooks.slack.com/services/AAAAAA/BBBBBBBB/CCCCCCCCCC",

health_check_config it's optional key, also timeout is optional (default is 3 sec)

This param tells how long each request will take before it reaches timeout.

"health_check_config": { 
    "timeout": 3 # in sec
},

Monthly Summary configuration:

"monthly_summary_config": {
 "send_monthly_summary_at_first_day_of_month": true, # send monthly summary
 "send_at_hour": "11:00" # send at hour
},

This section and all params of this is optional. Defaults are equal below example.

  "slack_connector_config": {
    "send_healthy": false, # send `healthy_message` on slack, for each "healthy" request
    "send_unhealthy": true, # send `unhealthy_message` on slack, for each "unhealthy" request
    "send_still_unhealthy": true, # send reminder `still_unhealthy_message` if url still "unhealthy"
    "send_still_unhealthy_delay": 10, # how ofeten send `still_unhealthy_message` in min
    "send_back_to_healthy": true, # send `back_to_healthy_message` when url back to "healthy"
    "send_if_there_no_unhealthy": false, # send `send_if_there_no_unhealthy` after each run where no "unhealthy" urls
    "hello_message": ":wave: Hi, we are connected! Let's go! :tada:", # send for run `main.py` with `--test` flag
    "healthy_message": "URL {url} is fine :heart:",
    "unhealthy_message": "URL {url} is dead :firecracker::skull_and_crossbones::firecracker:",
    "no_unhealthy_message": "Everything is fine :green_heart:",
    "back_to_healthy_message": "URL {url}, back to live! :tada: Total dead time {how_long_was_unhealthy} min",
    "still_unhealthy_message": "URL {url}, is still dead :firecracker::skull_and_crossbones::firecracker: Total dead time {how_long_was_unhealthy} min"
    "monthly_summary": "Summary for last month: {summary} The remaining services had 100% efficiency last month!:tada:"
  },

Available tags for each message (tags doesn't work only for no_unhealthy_message)

{url} # requested url
{param} # requested param (look to `to_checks` section)
{status_code} # status_code after request
{error_message} # if request has some error message you can find it over this tag
{is_healthy} # true/fals
{how_long_was_unhealthy} # in min, if url was healthy this tag return 0
{summary} # only for monthly summary string of: f"{url_with_monthly_dead_time.url}: {url_with_monthly_dead_time.unhealthy_this_month} min, efficiency: {(self.AVERAGE_MINUTES_IN_MONTH-url_with_monthly_dead_time.unhealthy_this_month)/self.AVERAGE_MINUTES_IN_MONTH}%\n"

Main section, to_checks required list of json (it can be one json of course).

url_base- full URL you want checking. Tag {param} isn't required if you want check only one url. If you want check many url with the same base you can put tag {param}.

Each combo of url_base and his params will be requested. You can put many url_base each with diff params.

"to_checks": [
    {
      "url_base": "https://{param}.my_backend.com/",
      "params": [
        "backend_1",
        "backend_2",
        "back_end"
      ]
    },
    {
      "url_base": "https://my_app_fronted.com/rest_of_url/{param}",
      "params": [
        "front_1",
        "front_2"
      ]
    }
  ]

Your final configuration.json should look like this:

{
  "slack_webhook_url": "https://hooks.slack.com/services/AAAAAA/BBBBBBBB/CCCCCCCCCC",
  "health_check_config": { 
    "timeout": 3
  },
  "slack_connector_config": {
    "send_healthy": false,
    "send_unhealthy": true,
    "send_still_unhealthy": true,
    "send_still_unhealthy_delay": 10,
    "send_back_to_healthy": true,
    "send_if_there_no_unhealthy": false,
    "hello_message": ":wave: Hi, we are connected! Let's go! :tada:",
    "healthy_message": "URL {url} is fine :heart:",
    "unhealthy_message": "URL {url} is dead :firecracker::skull_and_crossbones::firecracker:",
    "no_unhealthy_message": "Everything is fine :green_heart:",
    "back_to_healthy_message": "URL {url}, back to live! :tada: Total dead time {how_long_was_unhealthy} min",
    "still_unhealthy_message": "URL {url}, is still dead :firecracker::skull_and_crossbones::firecracker: Total dead time {how_long_was_unhealthy} min"
  },
  "to_checks": [
    {
      "url_base": "https://{param}.my_backend.com/",
      "params": [
        "backend_1",
        "backend_2",
        "back_end"
      ]
    },
    {
      "url_base": "https://my_app_fronted.com/rest_of_url/{param}",
      "params": [
        "front_1",
        "front_2"
      ]
    }
  ]
}

4. Cron

To run scrip every 1 min I use cron on external server with ubuntu

crontab -e

Replace /health-check/source/bin/python by your venv location. Replace /health-check/health-check-slack/main.py by your location of main.py

* * * * * /health-check/source/bin/python /health-check/health-check-slack/main.py

5. Logs

Health Checker create file named logs Each request to url you checking create below log:

f"{datetime.now()} - url: {health_result.url} - param: {health_result.param} - status_code: {health_result.status_code} - is_healthy: {health_result.is_healthy}"

Each send message to slack create below log:

f"{datetime.now()} - send to slack: success - text: {text}"

Logs older than 30 days are automatically deleted.

6. TODO

Q1 2025

• async request
• custom message per specified status code