Collect Kong Gateway metrics with the Prometheus plugin

Uses: Kong Gateway decK

Deployment Platform:

Prerequisites

Kong Konnect

This is a Konnect tutorial and requires a Konnect personal access token.

Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
Export your token to an environment variable:
```
 export KONNECT_TOKEN='YOUR_KONNECT_PAT'
```

Run the quickstart script to automatically provision a Control Plane and Data Plane, and configure your environment:

 curl -Ls https://get.konghq.com/quickstart | bash -s -- -k $KONNECT_TOKEN -e KONG_STATUS_LISTEN=0.0.0.0:8100 --deck-output

This sets up a Konnect Control Plane named quickstart, provisions a local Data Plane, and prints out the following environment variable exports:

 export DECK_KONNECT_TOKEN=$KONNECT_TOKEN
 export DECK_KONNECT_CONTROL_PLANE_NAME=quickstart
 export KONNECT_CONTROL_PLANE_URL=https://us.api.konghq.com
 export KONNECT_PROXY_URL='http://localhost:8000'

Copy and paste these into your terminal to configure your session.

Kong Gateway running

This tutorial requires Kong Gateway Enterprise. If you don’t have Kong Gateway set up yet, you can use the quickstart script with an enterprise license to get an instance of Kong Gateway running almost instantly.

Export your license to an environment variable:

 export KONG_LICENSE_DATA='LICENSE-CONTENTS-GO-HERE'

Run the quickstart script:

 curl -Ls https://get.konghq.com/quickstart | bash -s -- -e KONG_LICENSE_DATA 

Once Kong Gateway is ready, you will see the following message:

 Kong Gateway Ready

decK

decK is a CLI tool for managing Kong Gateway declaratively with state files. To complete this tutorial you will first need to install decK.

Required entities

For this tutorial, you’ll need Kong Gateway entities, like Gateway Services and Routes, pre-configured. These entities are essential for Kong Gateway to function but installing them isn’t the focus of this guide. Follow these steps to pre-configure them:

Run the following command:

echo '
_format_version: "3.0"
services:
  - name: example-service
    url: http://httpbin.konghq.com/anything
routes:
  - name: example-route
    paths:
    - "/anything"
    service:
      name: example-service
' | deck gateway apply -

To learn more about entities, you can read our entities documentation.

Enable the Prometheus plugin

Before you configure Prometheus, enable the Prometheus plugin on Kong Gateway:

echo '
_format_version: "3.0"
plugins:
  - name: prometheus
    config:
      status_code_metrics: true
' | deck gateway apply -

Configure Prometheus

Create a prometheus.yml file:

touch prometheus.yml

Now, add the following to the prometheus.yml file to configure Prometheus to scrape Kong Gateway metrics:

scrape_configs:
 - job_name: 'kong'
   scrape_interval: 5s
   static_configs:
     - targets: ['kong-quickstart-gateway:8001']

scrape_configs:
 - job_name: 'kong'
   scrape_interval: 5s
   static_configs:
     - targets: ['kong-quickstart-gateway:8100']

Run a Prometheus server, and pass it the configuration file created in the previous step:

docker run -d --name kong-quickstart-prometheus \
  --network=kong-quickstart-net -p 9090:9090 \
  -v $(PWD)/prometheus.yml:/etc/prometheus/prometheus.yml \
  prom/prometheus:latest

Prometheus will begin to scrape metrics data from Kong Gateway.

Validate

You can validate that the plugin is collecting metrics by generating traffic to the example service.

Run the following in the same terminal:

sleep 1 && curl "$KONNECT_PROXY_URL/anything"

sleep 1 && curl "http://localhost:8000/anything"

Run the following to query the collected kong_http_requests_total metric data:

curl -s 'localhost:9090/api/v1/query?query=kong_http_requests_total'

This should return something like the following:

{"status":"success","data":{"resultType":"vector","result":[{"metric":{"__name__":"kong_http_requests_total","code":"200","instance":"kong-quickstart-gateway:8001","job":"kong","route":"example-route","service":"example-service","source":"service","workspace":"default"},"value":[1749000790.826,"42"]}]}}

You can also view the Prometheus expression viewer by opening http://localhost:9090/graph in a browser.

Cleanup

Prometheus

Once you are done experimenting with Prometheus, you can use the following commands to stop the Prometheus server you created in this guide:

docker stop kong-quickstart-prometheus

Destroy the Kong Gateway container

curl -Ls https://get.konghq.com/quickstart | bash -s -- -d

Clean up Konnect environment

If you created a new control plane and want to conserve your free trial credits or avoid unnecessary charges, delete the new control plane used in this tutorial.

Next Steps

Review the Prometheus plugin configuration reference