Store Nginx Access Logs in Grafana Loki with Logging operator

This guide describes how to collect application and container logs in Kubernetes using the Logging operator, and how to send them to Grafana Loki.

The following figure gives you an overview about how the system works. The Logging operator collects the logs from the application, selects which logs to forward to the output, and sends the selected log messages to the output. For more details about the Logging operator, see the Logging operator overview.

Deploy Loki and Grafana 🔗︎

1. Add the chart repositories of Loki and Grafana using the following commands:

   helm repo add grafana https://grafana.github.io/helm-charts
   helm repo add loki https://grafana.github.io/loki/charts
   helm repo update
   

2. Install Loki into the logging namespace:

   helm upgrade --install --create-namespace --namespace logging loki loki/loki
   

   Grafana Loki Documentation

3. Install Grafana into the logging namespace:

    helm upgrade --install --create-namespace --namespace logging grafana grafana/grafana \
    --set "datasources.datasources\\.yaml.apiVersion=1" \
    --set "datasources.datasources\\.yaml.datasources[0].name=Loki" \
    --set "datasources.datasources\\.yaml.datasources[0].type=loki" \
    --set "datasources.datasources\\.yaml.datasources[0].url=http://loki:3100" \
    --set "datasources.datasources\\.yaml.datasources[0].access=proxy"
   

Deploy the Logging operator and a demo application 🔗︎

Install the Logging operator and a demo application to provide sample log messages.

Deploy the Logging operator with Helm 🔗︎

To install the Logging operator using Helm, complete these steps.

Note: For the Helm-based installation you need Helm v3.2.1 or later.

1. Add the chart repository of the Logging operator using the following commands:

   helm repo add banzaicloud-stable https://kubernetes-charts.banzaicloud.com
   helm repo update
   

2. Install the Logging operator into the logging namespace:

   helm upgrade --install --wait --create-namespace --namespace logging logging-operator banzaicloud-stable/logging-operator
   

3. Install the demo application and its logging definition.

   helm upgrade --install --wait --create-namespace --namespace logging logging-demo banzaicloud-stable/logging-demo \
     --set "loki.enabled=True"
   

4. Validate your deployment.

5. Create the logging resource.

   kubectl -n logging apply -f - <<"EOF"
   apiVersion: logging.banzaicloud.io/v1beta1
   kind: Logging
   metadata:
     name: default-logging-simple
   spec:
     fluentd: {}
     fluentbit: {}
     controlNamespace: logging
   EOF
   

   Note: You can use the ClusterOutput and ClusterFlow resources only in the controlNamespace.

6. Create a Loki output definition.

   kubectl -n logging apply -f - <<"EOF"
   apiVersion: logging.banzaicloud.io/v1beta1
   kind: Output
   metadata:
    name: loki-output
   spec:
    loki:
      url: http://loki:3100
      configure_kubernetes_labels: true
      buffer:
        timekey: 1m
        timekey_wait: 30s
        timekey_use_utc: true
   EOF
   

   Note: In production environment, use a longer timekey interval to avoid generating too many objects.

7. Create a flow resource.

   kubectl -n logging apply -f - <<"EOF"
   apiVersion: logging.banzaicloud.io/v1beta1
   kind: Flow
   metadata:
     name: loki-flow
   spec:
     filters:
       - tag_normaliser: {}
       - parser:
           remove_key_name_field: true
           reserve_data: true
           parse:
             type: nginx
     match:
       - select:
           labels:
             app.kubernetes.io/name: log-generator
     localOutputRefs:
       - loki-output
   EOF
   

8. Install the demo application.

   kubectl -n logging apply -f - <<"EOF"
   apiVersion: apps/v1
   kind: Deployment
   metadata:
    name: log-generator
   spec:
    selector:
      matchLabels:
        app.kubernetes.io/name: log-generator
    replicas: 1
    template:
      metadata:
        labels:
          app.kubernetes.io/name: log-generator
      spec:
        containers:
        - name: nginx
          image: banzaicloud/log-generator:0.3.2
   EOF
   

9. Validate your deployment.

Validate the deployment 🔗︎

Grafana Dashboard 🔗︎

1. Use the following command to retrieve the password of the Grafana admin user:

   kubectl get secret --namespace logging grafana -o jsonpath="{.data.admin-password}" | base64 --decode ; echo
   

2. Enable port forwarding to the Grafana Service.

   kubectl -n logging port-forward svc/grafana 3000:80
   

3. Open the Grafana Dashboard: http://localhost:3000

4. Use the admin username and the password retrieved in Step 1 to log in.

5. Select Menu > Explore, select Data source > Loki, then select Log labels > namespace > logging. A list of logs should appear.

   

If you don’t get the expected result you can find help in the troubleshooting section.