hello-monitoring 
Quis custodiet ipsos custodes? (Decimus Iunius Iuvenalis)
Hello Monitoring is a simple and stupid monitoring service powered by Docker and Bash.
It is built from an Alpine image. It uses crond to send GET request via cURL periodically, then it analyses the response and finally send you a notification.
Quick start
docker pull arpinum/hello-monitoring
docker run -e URL="https://google.com" -e EXPECTED_RESPONSE="Google" -ti hello-monitoring:latest
Docker compose example
The example folder contains a simple docker-compose.yml example which describes a fake web app and an Hello Monitoring instance.
External notification services
The only supported service is Slack at the moment. Just set the SLACK_WEBHOOK_URL variable to send notifications via your previously configured incoming webhook.
Configuration
All configuration is done via environment variables:
| Variable | Description |
|---|---|
| CRON | cron expression to use with crond. Default is * * * * * (every minutes). |
| URL | A GET request will be sent to the URL. This is mandatory. |
| EXPECTED_RESPONSE | Regex that will test the GET response. This is mandatory. |
| NAME | Name of the service to monitor. Default is the truncated URL. |
| NOTIFY_ON_SUCCESS | Success messages will be sent to external notification services. yes or no. Default is no. |
| NOTIFY_ON_ERROR | Error messages will be sent to external notification services. yes or no. Default is no. |
| NOTIFY_ON_CHANGE | Messages will be sent to external notification services when status change (e.g. error to success or conversely). yes or no. Default is yes. |
| SLACK_WEBHOOK_URL | If present, notifications will be sent to this webhook. |
FAQ
How can i monitor multiple services ?
Just start multiple containers with different configurations.
But, I already have 13 micro services :/
You now have 26 micro services :) An architecture to be proud of.
How can i send notifications via email, messenger, icq, or fax ?
You cannot. Hello Monitoring is a dumb service.