Grafana configuration

Configure Grafana datasources, dashboards, and authentication.

Grafana is the visualization layer of this stack. It connects to Prometheus for metrics and Loki for logs, and lets you build dashboards and run ad-hoc queries from a single UI.

Docker Compose service

grafana:
  image: grafana/grafana:latest
  container_name: grafana
  ports:
    - "3000:3000"
  environment:
    - GF_SECURITY_ADMIN_PASSWORD=admin

• image — uses the official grafana/grafana:latest image.
• ports — maps host port 3000 to container port 3000, making the Grafana UI available at http://localhost:3000.
• environment — sets the admin password via the GF_SECURITY_ADMIN_PASSWORD environment variable.

Default login

The default credentials for this stack are:

Field	Value
Username	admin
Password	admin

Change the default admin password before exposing Grafana on a non-loopback interface. Update the GF_SECURITY_ADMIN_PASSWORD value in docker-compose.yml and restart the container, or change the password through Profile → Change password after logging in.

Changing the admin password

To set a different password, update the environment variable in docker-compose.yml:

environment:
  - GF_SECURITY_ADMIN_PASSWORD=your-new-password

Then restart the Grafana container:

docker compose restart grafana

Adding datasources

Grafana must be connected to Prometheus and Loki before you can query data or build dashboards. Use the following internal URLs — both use Docker’s internal DNS, so the connections work entirely inside the Docker network:

Datasource	URL
Prometheus	http://prometheus:9090
Loki	http://loki:3100

1. Open the datasource settings

   Log in to Grafana at http://localhost:3000. In the left sidebar, go to Connections → Data sources.

2. Add a new data source

   Click Add new data source and select the datasource type (for example, Prometheus).

3. Enter the connection URL

   In the URL field, enter the internal address for the datasource. Use http://prometheus:9090 for Prometheus or http://loki:3100 for Loki.

4. Save and test

   Click Save & test. Grafana sends a probe request to the datasource and confirms the connection is working.

5. Repeat for the second datasource

   Go back to Connections → Data sources → Add new data source and repeat the steps for Loki.

Building a dashboard

Once your datasources are configured you can create a dashboard to visualize metrics and logs:

1. Create a new dashboard

   In the left sidebar, click the + icon and select New dashboard.

2. Add a visualization

   Click Add visualization and choose a datasource — select Prometheus to query metrics or Loki to query logs.

3. Write a query

   Enter a PromQL expression (for Prometheus) or a LogQL expression (for Loki) in the query editor. For example, use {job="varlogs"} to display all logs collected by Promtail.

4. Save the dashboard

   Click Save dashboard, give it a name, and click Save.