Elastic Container Instance:Configure log collection for an elastic container instance

Background information

Alibaba Cloud Simple Log Service is an end-to-end data logging service. You can use Simple Log Service to collect, consume, deliver, query, and analyze log data without performing further development. For more information, see What is Simple Log Service?

Feature description

By default, if log collection is enabled for an elastic container instance, a project and a machine group are generated in each region by default:

• The name of the project is eci-log-default-project-{Region}-{The account ID}.

• The name of the machine group is eci-log-default-machine-group-{Region}.

You may need to customize Logstores and projects to collect logs of elastic container instances based on your business requirements. If you use elastic container instances together with different applications and services, you may need to add elastic container instances to different machine groups. You can use one of the following methods to perform log configurations, such as the project, Logstore, and machine group:

• Use the environment variables of elastic container instances

  You can use the environment variables of containers to specify log configurations. If no project, Logstore, or machine group is created for the environment variables in Simple Log Service, the system automatically creates a project, Logstore, or machine group.

  Important

  You can perform log collection by using environment variables only when you create an elastic container instance. Environment variables that are passed in when you update an instance do not take effect.

• Use the Simple Log Service console or OpenAPI Explorer

  You can use the Simple Log Service console or OpenAPI Explorer to create a project, Logstore, and machine group. After you create a project, Logstore, and machine group, you can create a custom configuration file for the Logstore and apply the file to the machine group. Then, Simple Log Service exports logs of the elastic container instances to the Logstore.

This topic describes how to use environment variables to configure log collection for an elastic container instance.

Configuration description

If you create an elastic container instance by calling the CreateContainerGroup API operation, you can use the environment variables of containers to specify custom log configurations, such as the project, Logstore, Logtail configuration, machine group, shard, log retention period, and tag. The following part describes the format of and requirements on each configuration item when you specify a custom log configuration:

-name: aliyun_logs_{The configuration name}
-value: {The log collection path}

-name: aliyun_logs_{The configuration name}_project
-value: {The project name}

-name: aliyun_logs_{The configuration name}_logstore
-value: {The Logstore name}

  -name: aliyun_logs_{The configuration name}_machinegroup
  -value: {The machine group name}

-name: aliyun_logs_{The configuration name}_shard
-value: {The number of shards}    # Default value: 2. Valid values: 1 to 10.

-name: aliyun_logs_{The configuration name}_ttl
-value: {The number of days}    # Unit: days. Default value:90. Valid values: 1 to 3650.

--name: aliyun_logs_{The configuration name}_tags
-value: {The tag key}={The tag value}

Sample configurations:

For example, you need to specify the following log configurations:

• Logstore and Logtail configuration: Stdout logs are stored in the Logstore named stdout-test. Text logs are stored in the Logstore named file-test.

• Project: eci-test-project

• Machine group: eci-test-mg

The following example shows how to specify the log configurations:

# Configure the collection of stdout logs.
'Container.1.EnvironmentVar.1.Key': 'aliyun_logs_stdout-test',
'Container.1.EnvironmentVar.1.Value': 'stdout',
'Container.1.EnvironmentVar.2.Key': 'aliyun_logs_stdout-test_project',
'Container.1.EnvironmentVar.2.Value': 'eci-test-project',
'Container.1.EnvironmentVar.3.Key': 'aliyun_logs_stdout-test_machinegroup',
'Container.1.EnvironmentVar.3.Value': 'eci-test-mg',
# Configure the collection of text logs.
'Container.1.EnvironmentVar.4.Key': 'aliyun_logs_file-test',
'Container.1.EnvironmentVar.4.Value': '/log/*.log',
'Container.1.EnvironmentVar.5.Key': 'aliyun_logs_file-test_project',
'Container.1.EnvironmentVar.5.Value': 'eci-test-project',
'Container.1.EnvironmentVar.6.Key': 'aliyun_logs_file-test_machinegroup',
'Container.1.EnvironmentVar.6.Value': 'eci-test-mg',

If you enable log collection and specify environment variables based on the preceding configurations when you create an elastic container instance, the logs of the instance can be collected to the corresponding Logstore of the project.

• If you have not created a Logstore or Logtail configuration, the system automatically creates a Logstore or Logtail configuration based on the input environment variables.

• If you use an existing Logstore and Logtail configuration, make sure that Docker File is enabled for the Logtail configuration. Otherwise, Simple Log Service cannot collect logs for the elastic container instance.

  
  Note

  If you do not want to enable Docker File, you must manually mount the log directory to the emptyDir volume before Simple Log Service can collect logs.

The following figure shows the configuration effect.

• Collection of stdout logs

  

• Collection of text logs