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Observability and Prometheus

· 3 min read
CheverJohn

Observability (monitoring functionality) has always played an important role in system maintenance. A good monitoring system can help engineers quickly understand the status of services running in production environments and can locate problems or give early warning of anomalies when they occur.

Prometheus is a leading open-source project focused on metrics and alerting that has changed the way the world does monitoring and observability. And Apache APISIX Ingress Controller has enhanced its support for Prometheus Metrics in recent releases, adding a new feature for use in conjunction with the public-api plugin. This article will introduce how to configure public-api to protect Prometheus to collect Apache APISIX Ingress Controller's Metrics data.

Initial Knowledge about public-api​

When users develop custom plugins in Apache APISIX, they can define some APIs (hereinafter referred to as public API) for the plugins. In practical application scenarios, the provided interface is for internal calls, rather than being open on the public network for anyone to call.

Therefore, Apache APISIX has designed a public-api plugin. With this plugin, you can solve the pain points of using the public API. You can set a custom URI for the public API and configure any type of plugin. For more information about public-api, see the public-api plugin's document.

The main role of the public-api plugin in this document is to protect the URI exposed by Prometheus.

Note: One thing we should note is that this feature is only available in APISIX version 2.13 and later.

Begin to access Apache APISIX Prometheus Metrics​

Step1: Install APISIX Ingress Controller​

First, we deploy Apache APISIX, ETCD, and APISIX Ingress Controller to a local Kubernetes cluster via Helm.

helm repo add apisix https://charts.apiseven.com
helm repo update
kubectl create namespace ingress-apisix
helm install apisix apisix/apisix --namespace ingress-apisix \
 --set ingress-controller.enabled=true

After installation, please wait until all services are up and running. Specific status confirmation can be checked with the following command.

kubectl get all -n ingress-apisix

Step 2: Enable Prometheus Plugin​

If you need to monitor Apache APISIX at the same time, you can create the following ApisixClusterConfig resource.

apiVersion: apisix.apache.org/v2beta3
kind: ApisixClusterConfig
metadata:
  name: default
spec:
  monitoring:
    prometheus:
      enable: true

Step 3: Enable public-api Plugin​

This is a basic routing setup, please note that further configuration should be done based on your local backend service information. The main solution concept is to use the public-api plugin to protect the routes exposed by Prometheus. For a more detailed configuration, you can refer to the example section of the public-api plugin.

apiVersion: apisix.apache.org/v2beta3
kind: ApisixRoute
metadata:
  name: prometheus-route
spec:
  http:
  - name: public-api
    match:
      hosts:
      - test.prometheus.org
      paths:
      - /apisix/prometheus/metrics
    backends:
    ## Please notice that there must be your actual "serviceName" and "servicePort"
    - serviceName: apisix-test-prometheus
      servicePort: 9180
    plugins:
    - name: public-api
      enable: true

Step 4: Collect the Metrics​

Now you can then get the indicator parameters by requesting command access.

kubectl exec -it -n ${namespace of Apache APISIX} ${Pod name of Apache APISIX} -- curl http://127.0.0.1:9180/apisix/admin/routes -H 'X-API-Key: edd1c9f034335f136f87ad84b625c8f1'

kubectl exec -it -n ${namespace of Apache APISIX} ${Pod name of Apache APISIX} -- curl http://127.0.0.1:9080/headers -H 'Host: test.prometheus.org'