This is a little tool to keep track on a set of nodes, and see if they keep in step or if they go out of consensus.

1. Copy the config.example.toml into a config.toml file and fill in the required information
2. with Docker: docker run -d --name nodemonitor -p 8080:8080 -v <path-to-config.toml>/config.toml:/config.toml holiman/nodemonitor:latest /config.toml
3. Access the webpage by navigating to http://localhost:8080

It shows a neat little dashboard, where 'interesting' points of differing opinions are shown:

It also has support for pushing metrics to influxdb, so you can get nice charts and alerts from all/any node which supports basic set of standard rpc methods.