This topic describes how to configure a YAML file to export the logs of a Container
Service for Kubernetes (ACK) cluster to Log Service, without the need to modify the
application. In addition, an application that can be managed through API operations
is deployed in the ACK cluster. The application is used to generate logs for testing
purposes.
Background information
Log4j is an open source project of Apache. Log4j consists of three components: log
level, log output destination, and log output format. You can configure Log4Appender
to export log data to the console, a log file, a GUI component, a socket server, an
NT event viewer, or a UNIX syslog daemon.
Procedure
- Configure Log4jAppender in Log Service.
- Create a project in Log Service.
In this example, a project named k8s-log4j is created in the China (Hangzhou) region
where the ACK cluster is deployed. For more information, see
Create a project.
Note We recommend that you create a project in the region where the ACK cluster is deployed.
When a Log Service project and an ACK cluster are deployed in the same region, logs
are transmitted within the internal network. This enables real-time collection and
quick retrieval of log data. This also avoids cross-region transmission, which requires
additional bandwidth and time costs.

- Create a Logstore for the k8s-log4j project.
In this example, a Logstore named k8s-logstore is created. For more information, see
Create a Logstore.

- After the k8s-logstore Logstore is created, a dialog box appears, which shows instructions
on how to use the Data Import wizard.
- Select Log4jAppender under Custom Code and configure the settings by performing the steps that are provided on the page.
In this example, Log4jAppender is configured with the default settings. You can also
customize the settings to meet your business requirements.

- Configure Log4jAppender for the ACK cluster.
- Connect to your ACK cluster.
- Obtain the demo-deployment.yaml file and configure the
JAVA_OPTS
environment variable. The following is a sample template of the
demo-deployment.yaml 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 ## Take note of the following fields
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
Note The following information is displayed:
-Dproject
: the name of your project in Log Service. In this example, the name of the project
is k8s-log4j.
-DlogStore
: the name of your Logstore in Log Service. In this example, the name of the Logstore
is k8s-logstore.
-Dendpoint
: the service endpoint of Log Service. You must configure the service endpoint based
on the region where the Log Service project is deployed. For more information, see
Service endpoints. In this example, the service endpoint is cn-hangzhou.log.aliyuncs.com.
-Daccess_key_id
: your AccessKey ID.
-Daccess_key
: your AccessKey secret.
- Run the following command to create a Deployment:
kubectl create -f demo-deployment.yaml
- Obtain the demo-Service.yaml file and run the following command to create a Service:
You do not need to modify the configurations in the
demo-Service.yaml file.
kubectl create -f demo-service.yaml
- Generate Kubernetes cluster logs.
You can run the
kubectl get
command to view the Deployment status of the related resource objects. After the
Deployment and Service are deployed, run the
kubectl get svc
command to check the external IP address of the Service, which is EXTERNAL-IP.
Command:
kubectl get svc
Output:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
log4j-appender-demo-spring-boot-svc LoadBalancer 172.21.XX.XX 120.55.XXX.XXX 8080:30398/TCP 1h
In this example, you can run the
login
command to generate Kubernetes cluster logs, in which
K8 S_SERVICE_IP
is
EXTERNAL-IP
.
curl http://${K8S_SERVICE_IP}:8080/login?name=bruce
- View logs in Log Service
- In the Projects section of the Log Service console, find and click the k8s-log4j project to go to
the details page of the project.
- Click the
icon on the right side of the k8s-logstore Logstore and select Search & Analysis to view the logs of the Kubernetes cluster.