Setting up the monitoring with the Prometheus server

This section explains, in the case of a Kubernetes deployment, how to use SonarQube Community Build's native integration with Prometheus to collect the Prometheus metrics.

Introduction

The SonarQube Community Build’s Helm chart triggers the deployment of a Prometheus server that will pull the metrics from the SonarQube Community Build instance. The deployment process is as follows:

1. When you install the SonarQube Community Build’s Helm chart in the Kubernetes cluster, the chart creates a PodMonitor resource (podmonitor.yaml) which configures the pulling of metrics from SonarQube Community Build.
2. The Prometheus operator deploys a Prometheus server based on the created PodMonitor resource. 
3. The Prometheus server will pull the metrics from SonarQube Community Build according to the PodMonitor configuration. To pull the metrics from the Web API endpoint, it needs to authenticate to the Web API. (The Helm chart sets up the PodMonitor to use the Bearer authentication scheme.)

The figure below illustrates this process. 

Monitoring setup roadmap

To set up the monitoring of SonarQube Community Build with the Prometheus server:

1. Set up the authentication of the Prometheus server to the Web API’s monitoring endpoint.
2. Enable the JMX Exporter. 
3. Configure the collection of the JMX metrics.
4. Set up the export of the metrics to an observability platform. See the List of Prometheus metrics.

These steps are described below.

Setting up the Prometheus server authentication to the Web API endpoint

The PodMonitor needs to authenticate to the SonarQube Community Build’s Web API for getting metrics from the /api/monitoring/metrics endpoint. To setup this authentication, you must define the monitoring password in values.yaml: the Helm chart will store this value in the SONAR_WEB_SYSTEMPASSCODE environment variable on SonarQube Community Build.

To setup the monitoring passcode in SonarQube Community Build, use one of the following methods (see also the Helm chart documentation):

• Define the passcode in the monitoringPasscode property within the values.yaml file (default value is “define_it”).
  For security reasons, this method is not recommended.
• Use a secret that contains the passcode that will be retrieved at runtime, and define the following properties in values.yaml:
  • monitoringPasscodeSecretName: name of the secret object.
  • monitoringPasscodeSecretKey: key identifying the passcode to be extracted from the secret object.

Enabling the export of the JMX metrics

To expose the Prometheus JMX metrics, the JMX exporter must be enabled in the Helm chart configuration as follows:

• Add the following block in the values.yaml file of the SonarQube Community Build Helm chart:

prometheusExporter:
  enabled: true
  config:
    rules:
      - pattern: ".*"

Configuring the collection of the JMX metrics

By default, the SonarQube Community Buildv’s Helm chart does not collect the JMX metrics. If you want the Prometheus server to collect the JMX metrics, you must create and configure a PodMonitor resource that will be used by the Prometheus server to collect the JMX metrics. 

Proceed as follows:

• Create a podmonitor.yaml file (as illustrated below) and apply it to the Kubernetes cluster.

apiVersion: monitoring.coreos.com/v1
kind: PodMonitor
metadata:
  name: sonarqube
  namespace: monitoring
spec:
  namespaceSelector:
    matchNames:
    - sonarqube
  podMetricsEndpoints:
  - interval: 30s
    path: /
    scheme: http
    targetPort: monitoring-ce
  - interval: 30s
    path: /
    scheme: http
    targetPort: monitoring-web
  selector:
    matchLabels:
      app: sonarqube