Logging

Logging in the Kubernetes cluster is handled by a Logging operator. This tool allows the creation of customised logging pipelines that meet user requirements.

The logging pipeline consists of two components, SyslogNGFlow and SyslogNGOutput. SyslogNGFlow specifies the log selection and log filters. SyslogNGOutput specifies the output destination of the logs.

SyslogNGFlow

The SyslogNGFlow specifies what logs should be sent to the final output destination. To do so, it uses match statements that support logical operators and, or and not. SyslogNGFlow must have at least one match statement to transfer logs.

Example

You might use the example configuration below to collect all pod logs from a namespace. Specify the namespace and the name of the related SyslogNGOutput resource.

apiVersion: logging.banzaicloud.io/v1beta1
kind: SyslogNGFlow
metadata:
  name: syslog-flow
  namespace: [your_namespace]
spec:
  loggingRef: cerit-logging-root
  match:
    regexp:
      value: json.kubernetes.labels.app.kubernetes.io/instance
      pattern: "*"
      type: glob
  localOutputRefs:
    - [output_resource_name]

The part loggingRef: cerit-logging-root is important and must be set to this exact value.

To see all routing options, see official documentation.

SyslogNGOutput

SyslogNGOutput configures the output destination of the logs. SyslogNGOutput can configure only one output plugin within the specification.

Example

You might use the example configuration below to transfer logs using the Syslog protocol. Specify the resource name, namespace, IP address and port. Make sure you use the same name as in localOutputRefs.

apiVersion: logging.banzaicloud.io/v1beta1
kind: SyslogNGOutput
metadata:
  name: [output_resource_name]
  namespace: [your_namespace]
spec:
  loggingRef: cerit-logging-root
  syslog:
      host: [ip_address]
      port: [port]

The part loggingRef: cerit-logging-root is important and must be set to this exact value.

To see a complete list of available output plugins, see official documentation.

Logging pipeline deployment

To create a new logging pipeline, apply the resource configurations from a YAML file.

kubectl apply -f [path_to_yaml_file]