CKA Quick Check Points -- Logs & Configs

Quick recap for logs & configs. Details can click the title link or check the official doc.

1. Log

1.1 Files

• /var/log/

  • Pod: /var/log/pods/<namespace>/<pod-name>/<container-name>.log

  • Etcd: /var/log/etcd.log

  • kubelet: /var/log/syslog

1.2 CMD

# 1. components log
grep kubelet /var/log/syslog
journalctl -u [kubectl|kube-controller-manager|kube-scheduler|kube-apiserver|etcd|docker|containerd]
kubectl logs <pod-name> -n kube-system
# 2. Pod log
kubectl describe pod <pod-name> -n kube-system
kubectl logs <pod-name> -c <container-name>
# use crictl or docker (in case when docker is used) to check the logs and process
# crictl ps/logs

1.3 sidecar

sidecar container used for logging

official doc

2. Config

2.1 Files

• /etc/kubernetes/: most k8s configuration files.

  • /etc/kubernetes/manifest: static pod config files

• /var/lib/kubelet/: kubelet related data and configuration.

• /var/lib/etcd/: etcd data.

• /etc/systemd/system/: systemd service configuration files.

2.2 CMD

# View the active kubeconfig settings.
kubectl config view
# check the corresponding pods
kubectl describe pod <pod-name> -n kube-system
# use systemctl cat
systemctl cat [kubectl|kube-controller-manager|kube-scheduler|kube-apiserver|etcd|docker|containerd]
# can even use find
find / | grep kubeadm

3. Context

kubectl config current-context

4. Jobs

kubectl delete jobs --all
kubectl get pods -w