Enable application logging and monitoring

This page shows how to configure a cluster for Google Distributed Cloud so that custom logs and metrics from user applications are sent to Cloud Logging and Cloud Monitoring.

Enabling Logging and Monitoring for user applications

To enable Logging and Monitoring for your applications, use the spec.clusterOperations.enableApplication field in the cluster configuration file.

1. Update the cluster configuration file to set enableApplication to true:

   apiVersion: v1
   kind: Namespace
   metadata:
     name: cluster-user-basic
   ---
   apiVersion: baremetal.cluster.gke.io/v1
   kind: Cluster
   metadata:
     name: user-basic
     namespace: cluster-user-basic
   spec:
     type: user
     ...
     clusterOperations:
       projectID: project-fleet
       location: us-central1
       enableApplication: true
       ...
   

2. Use bmctl update to apply your changes:

   bmctl update cluster -c CLUSTER_NAME --admin-kubeconfig=ADMIN_KUBECONFIG
   

   Replace the following:

   • CLUSTER_NAME: the name of the cluster to upgrade.
   • ADMIN_KUBECONFIG: the path to the admin cluster kubeconfig file.

Annotate workloads

To enable the collection of custom metrics from an application, add the prometheus.io/scrape: "true" annotation to the application's Service or Deployment manifest.

Run an example application

In this section, you create an application that writes custom logs and exposes a custom metric.

1. Save the following Service and Deployment manifests to a file named my-app.yaml. Notice that the Service has the annotation prometheus.io/scrape: "true":

   kind: Service
   apiVersion: v1
   metadata:
     name: "monitoring-example"
     namespace: "default"
     annotations:
       prometheus.io/scrape: "true"
   spec:
     selector:
       app: "monitoring-example"
     ports:
       - name: http
         port: 9090
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: "monitoring-example"
     namespace: "default"
     labels:
       app: "monitoring-example"
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: "monitoring-example"
     template:
       metadata:
         labels:
           app: "monitoring-example"
       spec:
         containers:
         - image: gcr.io/google-samples/prometheus-dummy-exporter:latest
           name: prometheus-example-exporter
           imagePullPolicy: Always
           command:
           - /bin/sh
           - -c
           - ./prometheus-dummy-exporter --metric-name=example_monitoring_up --metric-value=1 --port=9090
           resources:
             requests:
               cpu: 100m
   

2. Create the Deployment and the Service:

   kubectl --kubeconfig CLUSTER_KUBECONFIG apply -f my-app.yaml

View application logs

View application metrics in the Google Cloud console

Your example application exposes a custom metric named example_monitoring_up. You can view the values of that metric in the Google Cloud console.

1. Go to the Metrics explorer in the Google Cloud console.

   Go to the Metrics explorer

2. For Resource type, select Kubernetes Pod.

3. For metric, select external/prometheus/example_monitoring_up.

4. In the chart, you can see that example_monitoring_up has a repeated value of 1.