Deploy Loki & Grafana for Lightweight Log Monitoring with Docker and SpringBoot

After a failed attempt to run SkyWalking on a low‑memory 2 GB server, the author switched to the lightweight Loki log aggregation system combined with Grafana for visualization, and provides a step‑by‑step guide to deploy both services with Docker Compose, integrate Loki into a SpringBoot application via the loki‑logback‑appender, and configure Grafana to display logs.

Environment Deployment

The setup consists of two components, Loki and Grafana, which together consume less than 1 GB of memory when run in Docker.

version: "3"

networks:
  loki:

services:
  loki:
    image: grafana/loki:latest
    ports:
      - "3100:3100"
    command: -config.file=/etc/loki/local-config.yaml
    networks:
      - loki

  grafana:
    environment:
      - GF_PATHS_PROVISIONING=/etc/grafana/provisioning
      - GF_AUTH_ANONYMOUS_ENABLED=true
      - GF_AUTH_ANONYMOUS_ORG_ROLE=Admin
    entrypoint:
      - sh
      - -euc
      - |
        mkdir -p /etc/grafana/provisioning/datasources
        cat <<EOF > /etc/grafana/provisioning/datasources/ds.yaml
        apiVersion: 1
        datasources:
        - name: Loki
          type: loki
          access: proxy
          orgId: 1
          url: http://loki:3100
          basicAuth: false
          isDefault: true
          version: 1
          editable: false
        EOF
        /run.sh
    image: grafana/grafana:latest
    ports:
      - "3000:3000"
    networks:
      - loki

Run the following command in the directory containing docker-compose.yaml to pull images and start the containers: docker-compose -f docker-compose.yaml up Verify the containers are running with:

docker ps

SpringBoot Integration with Loki

Integrate Loki by adding the loki-logback-appender-jdk8 dependency to your project:

<dependency>
    <groupId>com.github.loki4j</groupId>
    <artifactId>loki-logback-appender-jdk8</artifactId>
    <version>1.4.2</version>
</dependency>

Configure logback-spring.xml to use the Loki appender (excerpt):

<!-- Loki log upload -->
<springProperty name="serverIP" scope="context" source="spring.cloud.client.ip-address" defaultValue="0.0.0.0"/>
<springProperty name="serverPort" scope="context" source="server.port" defaultValue="0000"/>
<springProperty name="appName" scope="context" source="spring.application.name"/>
<springProperty name="lokiUrl" scope="context" source="loki.url"/>

<property name="APP_NAME" value="${appName}"/>
<property name="LOKI_URL" value="${lokiUrl}"/>

<appender name="LOKI" class="com.github.loki4j.logback.Loki4jAppender">
    <http class="com.github.loki4j.logback.ApacheHttpSender">
        <url>${LOKI_URL}/loki/api/v1/push</url>
    </http>
    <format>
        <label>
            <pattern>app=${APP_NAME},host=${HOSTNAME},instance=${serverIP}:${serverPort}, level=%level</pattern>
        </label>
        <message>
            <pattern>l=%level h=${HOSTNAME} i=${serverIP}:${serverPort} c=%logger{20} t=%thread | %msg %ex</pattern>
        </message>
        <sortByTime>true</sortByTime>
    </format>
</appender>
<root level="INFO">
    <appender-ref ref="LOKI"/>
</root>

Add the Loki endpoint in application.yml (replace with your server IP):

# Loki configuration
loki:
  url: http://192.168.11.11:3100

All logs emitted via Logback (e.g., log.error, log.info) will be sent to Loki and become searchable.

Grafana Visualization of Loki

Access Grafana at http://<em>server_ip</em>:3000/login (default credentials: admin / admin). After logging in, add a new data source:

Select Loki, set the URL to http://<em>container_name</em>:3100, and test the connection.

Once the data source is verified, create a dashboard and use a simple query such as {app="appName"} (where appName matches spring.application.name) to view logs from the SpringBoot service.