Implementing custom checks
Custom checks can be used to monitor a platform component if the available integration features are not adequate or an integration doesn't exist at all for that component. The Datadog API could be used as well in reporting custom-generated metrics to Datadog. We will explore this option with an example.
The process involved in implementing a check that publishes custom metrics is simple in Datadog and we can learn about that from the following example.
Continuing with the example of NGINX from the previous sections in this chapter, we will try to extend that integration by adding a custom metric to Datadog. This custom metric, kurian.nginx.error_log.size, tracks the size of the NGINX error log file. It's better to begin the metric name with a namespace specific to your company or department, as the metric is labeled in this example, to filter custom metrics easily.
Manually, the file size information could be gathered by running the command...
