Container Service for Kubernetes:Collect Log4j logs from Java applications to SLS

Step 1: Configure Log4j Appender in SLS

This step guides you to create an SLS project and Logstore. After configuring the Logstore data source as Log4j Appender, you can send Java application logs directly to SLS.

We recommend that you create the SLS project in the same region as your cluster. In this way, log data can be transmitted through the internal network, avoiding external bandwidth costs and network latency caused by cross-region transmission.

For more information about SLS project billing, see Billing overview.

1. Create an SLS project.

   The following introduces the core parameters. Other parameters can remain as default. For more information, see Manage a project.

   • Region: We recommend that you select the same region as your ACK cluster. In this example, China (Hangzhou) is selected.

   • Project Name: In this example, k8s-log4j is used.

2. Create a Logstore in the project.

   In this example, the Logstore Name is k8s-logstore, and other parameters remain as default. For more information, see Manage a logstore.

3. After k8s-logstore is created, follow the page prompts to access data.

   

4. Search and locate the Log4j access card, and follow the page prompts to complete the access.

   In this example, the default configuration is used. You can configure based on your specific log data usage scenarios.

Step 2: Integrate Log4j in your application

This step demonstrates how to integrate the Log4j Appender plug-in into a Java application by deploying a Spring Boot sample application. After integration, when the container starts, the SLS configuration is passed through the JAVA_OPTS environment variable, and Log4j automatically reads the parameters and sends logs to SLS in real time.

1. Obtain the demo-deployment.yaml file and configure the JAVA_OPTS environment variable.

   For more information about how to obtain the file, see demo-deployment.

   View the sample file

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: log4j-appender-demo-spring-boot
     labels:
       app: log4j-appender
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: log4j-appender
     template:
       metadata:
         labels:
           app: log4j-appender
       spec:
         containers:
         - name: log4j-appender-demo-spring-boot
           image: registry.cn-hangzhou.aliyuncs.com/jaegertracing/log4j-appender-demo-spring-boot:0.0.2
           env:
             - name: JAVA_OPTS            #  Set the JAVA_OPTS environment variable
               value: "-Dproject={your_project} -Dlogstore={your_logstore} -Dendpoint={your_endpoint} -Daccess_key_id={your_access_key_id} -Daccess_key={your_access_key_secret}"
           ports:
           - containerPort: 8080

   JAVA_OPTS configuration description:

   • -Dproject: SLS project name. In this example, k8s-log4j is used.

   • -Dlogstore: SLS Logstore name. In this example, k8s-logstore is used.

   • -Dendpoint: SLS service endpoint. Configure the service endpoint based on the region where your project is located. For more information,see Endpoints. In this example, cn-hangzhou.log.aliyuncs.com is used.

   • -Daccess_key_id: Replace with your AccessKey ID.

   • -Daccess_key: Replace with your AccessKey Secret.

2. Create a Deployment.

   kubectl create -f demo-deployment.yaml

3. Obtain the demo-Service.yaml file. You can keep the default configuration.

   For the file address, see demo-Service.

   View the sample file

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: log4j-appender
     name: log4j-appender-demo-spring-boot-svc
     namespace: default
   spec:
     ports:
     - port: 8080
       protocol: TCP
       targetPort: 8080
     selector:
       app: log4j-appender
     type: LoadBalancer

4. Deploy demo-Service.yaml to create a Service.

   kubectl create -f demo-service.yaml

Step 3: Test the log collection function

Step 4: View logs in the SLS console

You can log on to the SLS console to query and analyze logs.

1. Log on to the Simple Log Service console.

2. In the Projects section, click the target project to go to the project details page.

3. Click the icon on the right side of the Logstore and select Search & Analysis to view the logs output by the cluster.