Prometheus metrics

Kubernetes Ingress Controller, as well as Kong Gateway, both expose Prometheus metrics, under certain conditions:

Kubernetes Ingress Controller, since version 2.0, exposes Prometheus metrics for configuration updates.
Kong Gateway can expose Prometheus metrics for served requests, if the Prometheus plugin is enabled. See the Using KongPlugin resource guide for information on how to enable a plugin. Also, we provide a specific guide for integration with Prometheus and Grafana as well.

This document is a reference for the former type.

Metric name	Description
`ingress_controller_configuration_push_count[success=true\|false][protocol=db-less\|deck]`	Count of successful or failed configuration pushes to Kong. `protocol` describes the configuration protocol in use, which can be `db-less` or `deck`. `success` logs the status of configuration updates. If `success` is `false`, an unrecoverable error occurred. If `success` is `true`, the push succeeded with no errors.
`ingress_controller_translation_count[success=true\|false]`	Count of translations from Kubernetes state to Kong state. `success` logs the status of configuration updates. If `success` is `false`, an unrecoverable error occurred. If `success` is `true`, the translation succeeded with no errors.
`ingress_controller_configuration_push_duration_milliseconds[success=true\|false][protocol=db-less\|deck]`	The amount of time, in milliseconds, that it takes to push the configuration to Kong. `protocol` describes the configuration protocol in use, which can be `db-less` or `deck`. `success` logs the status of configuration updates. If `success` is `false`, an unrecoverable error occurred. If `success` is `true`, the push succeeded with no errors.

In addition to the above, Kubernetes Ingress Controller exposes more low-level performance metrics - these may however change from version to version, as they are provided by underlying frameworks of Kubernetes Ingress Controller.

A non-exhaustive list of these low-level metrics is present in the following places: