Collecting OpenEBS Logs ·

Overview of OpenEBS Logger

Logger is a Kubernetes job which can be run on a cluster to extract pod logs and cluster information. It helps in troubleshooting/debugging activities. Logger runs the logger container openebs/logger and it is recommended to run for a specific duration to capture logs while attempting to reproduce issues.

Benefits

Following are the benefits of using Logger.

The purpose of Logger is to obtain debug-information/quick logs in clusters where more standard logging frameworks like EFK are not already configured. Logger creates a simple support bundle which can be provided to debug teams.
This may be the case with most "non-production/development" infrastructures.

Where is the Logger found?

You can find the Logger file here.

How does Logger work?

Logger uses the following tool/command to work.

Logger uses a stern tool to collect the pod logs.
It uses kubectl commands to extract cluster information.

Prerequisite

Logger requires the kubeconfig file mounted as a configmap (passed to stern binary). kubeconfig file is generally found under /etc/kubernetes/admin.conf or ~/.kube/config path.

Running Logger

The following procedure helps you run Logger.

In the logger job's command, edit the logging duration (-d) and pod regex (-r) to specify which pods' logs should be captured and for how long.

For example, in the ./logger.sh -d 5 -r maya,openebs,pvc; command, the logs for pods starting with literals "maya", "openebs" and "pvc" are captured for a period of 5 minutes.

Note: The duration is arrived depending on the average time taken for the issue/bug to manifest from the time a pod starts.
Create a Kubernetes job to run logger using the kubectl apply -f debugjob.yaml command.
This job will run for the duration specified in the previous steps.
The logs thus collected are placed in a logbundle (tarball) in /mnt directory of the node in which the debug pod was scheduled.
Logs will be available in the node in which the debug pod/logger is scheduled when you run a kubectl get pod -o wide command.
Attach this log support bundle while raising issues on the OpenEBS repository.