Logging and Monitoring

• There is 1 metric server per kuberentes cluster

• kubelet has a subcomponent cAdvisor that is responsible for retrieving performace from pod and exposing them at kubelet API.

• This API is utilized by metric server.

Commands to view metrics

kubectl top node

kubectl top pod

Commands to view logs

kubectl logs -f <pod-name>

kubectl logs -f <pod-name> -c <container-name>

 # Return snapshot logs from pod nginx with only one container
  kubectl logs nginx
  
  # Return snapshot logs from pod nginx with multi containers
  kubectl logs nginx --all-containers=true
  
  # Return snapshot logs from all containers in pods defined by label app=nginx
  kubectl logs -l app=nginx --all-containers=true
  
  # Return snapshot of previous terminated ruby container logs from pod web-1
  kubectl logs -p -c ruby web-1
  
  # Begin streaming the logs of the ruby container in pod web-1
  kubectl logs -f -c ruby web-1
  
  # Begin streaming the logs from all containers in pods defined by label app=nginx
  kubectl logs -f -l app=nginx --all-containers=true
  
  # Display only the most recent 20 lines of output in pod nginx
  kubectl logs --tail=20 nginx
  
  # Show all logs from pod nginx written in the last hour
  kubectl logs --since=1h nginx
  
  # Show logs from a kubelet with an expired serving certificate
  kubectl logs --insecure-skip-tls-verify-backend nginx
  
  # Return snapshot logs from first container of a job named hello
  kubectl logs job/hello
  
  # Return snapshot logs from container nginx-1 of a deployment named nginx
  kubectl logs deployment/nginx -c nginx-1