kubectl logs - continuously

Question

kubectl logs -f <pod-id>

You can use the -f flag:

-f, --follow=false: Specify if the logs should be streamed.

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#logs

kubectl logs --help will guide you:

Example:

# Begin streaming the logs of the ruby container in pod web-1
kubectl logs -f -c ruby web-1

Flags:

-f, --follow[=false]: Specify if the logs should be streamed.

You can also add --since=10m or so start from that relative time ago.

I needed to access the logs of a long running pod, and -f began streaming logs from days ago, which would have taken hours to get to where I needed to view ( just the last couple minutes or so ).

There is a --since=10m flag, but that didn't seem to work for me.

What did wonders was --tail=100, where 100 is the number of recent lines to display.

Try this,

tail logs from pods

kubectl --tail <"no of lines"> logs <"pod_name">

Example :

kubectl --tail 100 logs app_pod

If you want to get the stream of logs from a multi pod app you can use kubetail, example:

kubectl get pods

NAME                   READY     STATUS    RESTARTS   AGE
app2-v31-9pbpn         1/1       Running   0          1d
app2-v31-q74wg         1/1       Running   0          1d

kubetail app2

With that command, kubetail is tailing the logs from pod app2-v31-9pbpn and app2-v31-q74wg

wait for kubes to spin up pod then move on...

k8s_pod=some_pod
kubectl get pods -w $k8s_pod | while read LOGLINE
do
   [[ "${LOGLINE}" == *"Running"* ]] && pkill -P $$ kubectl
done

tail logs

for line in $(kubectl get pods | grep $k8s_pod | awk '{print $1}'); do
    kubectl logs -f $line | tee logfile
done

look for success indicator

tail logfile | grep successful! 
RESULT=$?
exit $RESULT