Chapter 2. Accessing Prometheus to monitor Fuse applications on OpenShift

Procedure

1. Login to OpenShift with administrator permissions:

   $ oc login -u system:admin

2. Install the custom resource definitions necessary for running the Prometheus operator, where {$templates-base-url} is the location of the Fuse on OpenShift template files:

   $ oc create -f {$templates-base-url}\fuse-prometheus-crd.yml

   The Prometheus operator is now available to any namespace on the cluster.

3. Install the Prometheus operator to your namespace by using the following command syntax:

   $ oc process -f {$templates-base-url}/fuse-prometheus-operator.yml -p NAMESPACE=<YOUR NAMESPACE> | oc create -f -

   For example, use this command for a project (namespace) named myproject:

   oc process -f {$templates-base-url}/fuse-prometheus-operator.yml -p NAMESPACE=myproject | oc create -f -

   Note

   The first time that you install the Prometheus operator into a namespace, it might take a few minutes for the Prometheus resource pods to start. Subsequently, if you install it to other namespaces on your cluster, the Prometheus resource pods start much faster.

4. Instruct the Prometheus operator to monitor the Fuse application in the project by using the following command syntax::

   $ oc process -f {$templates-base-url}/fuse-servicemonitor.yml -p NAMESPACE=<YOUR NAMESPACE> -p FUSE_SERVICE_NAME=<YOUR FUSE SERVICE> | oc apply -f -

   For example, use this command for an OpenShift project (namespace) named myproject that includes a Fuse application named myfuseapp:

   oc process -f {$templates-base-url}/fuse-servicemonitor.yml -p NAMESPACE=myproject -p FUSE_SERVICE_NAME=myfuseapp | oc apply -f -

5. To open the Prometheus dashboard:

   1. Login to the OpenShift console.
   2. Open the project to which you added Prometheus.

   3. In the left pane, select Applications Routes.

      

   4. Click the Prometheus Hostname URL to open the Prometheus dashboard in a new browser tab or window.

      

   5. For information about getting started with Prometheus, go to: https://prometheus.io/docs/prometheus/latest/getting_started/

1. Create a custom Prometheus configuration file. You can use the contents of the default file (prometheus-config.yml https://raw.githubusercontent.com/jboss-fuse/application-templates/master/prometheus/prometheus-config.yml) as a guide for the format.

   You can use any name for the custom configuration file, for example: my-prometheus-config.yml.

2. Add your prometheus configuration file (for example, my-prometheus-config.yml) to your application’s src/main/fabric8-includes directory.

3. Create a src/main/fabric8/deployment.xml file within your application and add an entry for the AB_JMX_EXPORTER_CONFIG environment variable with its value set to your configuration file. For example:

   spec:
     template:
       spec:
         containers:
           -
             resources:
               requests:
                 cpu: "0.2"
               limits:
                 cpu: "1.0"
             env:
             - name: SPRING_APPLICATION_JSON
               value: '{"server":{"tomcat":{"max-threads":1}}}'
             - name: AB_JMX_EXPORTER_CONFIG
               value: "my-prometheus-config.yml"

   This environment variable applies to your application at the pod level.

4. Rebuild and deploy your application.