Container Service for Kubernetes:Collect and analyze CoreDNS logs

Method 1: Use the ACK console

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

2. On the Clusters page, click the name of the cluster that you want to manage and choose Operations > Log Center in the left-side navigation pane.

3. On the Log Center page, click the Network Component Logs tab and click Install.

   The system then automatically installs the relevant components and enables logging for CoreDNS.

Method 2: Use the CLI

You can use AliyunLogConfig CustomResourceDefinitions (CRDs) to describe logging configurations. alibaba-log-controller automatically configures Log Service settings and creates log reports based on the logging configurations. For more information about how to create an AliyunLogConfig CRD, see Manage custom resources.

Important

The following configurations take effect only when the default log format of CoreDNS is used. If CoreDNS uses a custom log format, you need to modify the regular expression in the Regex field.

For more information about how to customize the log format of CoreDNS, see log.

For more information about the log collection configuration and procedure, see Use CRDs to collect container logs in DaemonSet mode.

1. Create a YAML file named k8s-coredns-log.yaml. The following code block shows an example:

   apiVersion: log.alibabacloud.com/v1alpha1
   kind: AliyunLogConfig
   metadata:
     #     Your config name, must be unique in you k8s cluster.
     name: k8s-coredns-log
     namespace: kube-system
   spec:
     # logstore name to upload log
     logstore: coredns-log
     # logtail config detail
     productCode: k8s-coredns
     logtailConfig:
       inputType: plugin
       # logtail config name, should be same with [metadata.name]
       configName: k8s-coredns-log
       inputDetail:
         plugin:
           inputs:
           - type: service_docker_stdout
             detail:
               IncludeLabel:
                 io.kubernetes.container.name: coredns
               Stderr: true
               Stdout: true
           processors:
           - type: processor_regex
             detail:
               KeepSource: false
               KeepSourceIfParseError: true
               Keys:
               - level
               - remote
               - port
               - id
               - type
               - class
               - name
               - proto
               - size
               - do
               - bufsize
               - rcode
               - rflags
               - rsize
               - duration
               NoKeyError: true
               NoMatchError: false
               FullMatch: false
               Regex: \[([^]]+)]\s([^:]+):(\S+)\s+-\s+(\S+)\s+"(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+([^"]+)"\s+(\S+)\s+(\S+)\s+(\S+)\s+([\d\.]+).*
               SourceKey: content
           - type: processor_regex
             detail:
               KeepSource: false
               KeepSourceIfParseError: true
               Keys:
               - error
               - rcode
               - name
               - type
               - errorMsg
               NoKeyError: false
               NoMatchError: false
               FullMatch: false
               Regex: \[ERROR]\s+(plugin/errors):\s+(\S)+\s+(\S+)\s+([^:]*):\s+(.*)
               SourceKey: content

2. Run the following command to enable logging for CoreDNS:

   kubectl apply -f k8s-coredns-log.yaml