Container Service for Kubernetes:Collect application logs with pod environment variables

Create from an image

1. Log on to the ACK console. In the left navigation pane, click Clusters.

2. On the Clusters page, click the name of your cluster. In the left navigation pane, click Workloads > Deployments.

3. On the Deployments page, select a namespace from Namespace and click Create from Image.

   1. On the Basic Information tab, set the Application Name, number of Replicas:, and Type, then click Next.

   2. On the Container tab, configure the Log Service section.

      Note

      Only log collection parameters are covered here. See Create a stateless deployment for other parameters.

      Before configuring, ensure the logging plug-in is deployed on the cluster.logging plug-in is installed on the cluster.

      Parameter	Description
      Collection configuration When the collection configuration changes, manually delete the previous configuration to prevent duplicate log collection.	Click Collection Configuration and configure Logstore and Log Path in Container (Can be set to stdout). Logstore name. Can contain only lowercase letters, digits, and hyphens (-). If the specified Logstore does not exist, ACK Serverless creates it in the SLS project associated with the cluster. Log Path in Container: Path to collect. Example: /usr/local/tomcat/logs/catalina.*.log for Tomcat text logs. Note Setting the path to stdout collects both stdout and stderr from the container. Each collection configuration creates a Logtail configuration for the corresponding Logstore. By default, logs are collected in simple mode (line by line). For advanced collection methods, log on to the Simple Log Service console and modify the configuration in the corresponding project (prefixed with k8s-log by default) and Logstore.
      Custom tag	Click Custom Tag and configure the Tag Key and Tag Value. A key-value pair appended to collected log entries. Use custom tags to label container log data, such as a version number.

   3. Click Next. See Create a stateless deployment for subsequent steps.

Create from a YAML file

1. Log on to the ACK console. In the left navigation pane, click Clusters.

2. On the Clusters page, click the name of your cluster. In the left navigation pane, click Workloads > Deployments.

3. On the Deployments page, select a namespace from Namespace and click Create from YAML.

4. On the Create page, select a sample template, edit the Template in the YAML editor, and click Create.

   The YAML template uses standard Kubernetes syntax. To configure log collection, use env to add collection configurations and custom tags, and create corresponding volumeMounts and volumes. Sample pod YAML:

   apiVersion: v1
   kind: Pod
   metadata:
     name: my-demo
   spec:
     containers:
     - name: my-demo-app
       image: 'registry.cn-hangzhou.aliyuncs.com/log-service/docker-log-test:latest'
       args:
       - -c
       - mkdir -p /log;while true; do echo hello world; date; echo hello sls >> /var/log/test.log; sleep 1;done
       command:
       - /bin/sh
       env:
       ######### Configure environment variables ###########
       - name: aliyun_logs_log-stdout
         value: stdout
       - name: aliyun_logs_log-varlog
         value: /var/log/*.log
       - name: aliyun_logs_mytag1_tags
         value: tag1=v1
       ######### Configure Volume Mounts ###########
       volumeMounts:
       - name: volumn-sls-mydemo
         mountPath: /var/log
     volumes:
     - name: volumn-sls-mydemo
       emptyDir: {}

   Add these configurations to the pod YAML as needed:

   Note

   See Step 2: Advanced environment variable parameters for advanced requirements.

   1. Create collection configurations and custom tags with environment variables. All use the aliyun_logs_ prefix.

      1. To create a collection configuration:

         - name: aliyun_logs_log-stdout
           value: stdout
         - name: aliyun_logs_log-varlog
           value: /var/log/*.log

         This example creates two collection configurations using aliyun_logs_{key}, where {key} is log-stdout and log-varlog.

         • aliyun_logs_log-stdout: This env variable defines a log-stdout collection configuration, creates a log-stdout Logstore, and collects container stdout into the log-stdout Logstore.

         • aliyun_logs_log-varlog: This env variable creates a Logstore (log-varlog) and collection configuration (log-varlog) for path /var/log/*.log. Files from /var/log/*.log are sent to the log-varlog Logstore.

      2. To create a custom tag:

         - name: aliyun_logs_mytag1_tags
           value: tag1=v1

         The tag is appended to logs collected from this container. The tag key (mytag1 in this case) can contain only lowercase letters, digits, and hyphens (-).

   2. If the collection path is not stdout, create a corresponding volumeMounts. In this example, collecting /var/log/*.log requires a volumeMounts for /var/log.