Get name of most recently created pod

Question

In OpenShift, is there a more elegant way of obtaining the name of the most recently created pod in application my_app than this one?

name=$(oc get pods -l app=my_app -o=jsonpath='{range.items[*]}{.status.startTime}{"\t"}{.metadata.name}{"\n"}{end}' | sort -r | head -1 | awk '{print $2}')

The idea is to sort by .status.startTime and to output one .metadata.name. So far, I have not been successful in using oc get with both options --sort-by and -o jsonpath at the same time, so I have fallen back to Unix pipes in this version.

I am using OpenShift v3.9. I am also tagging this question for Kubernetes because it presumably applies to kubectl (instead of oc) in an analogous manner (without the -l app=my_app).

Cuddy

FWIW, you might also want to qualify based on status. oc get pods -o jsonpath='{.items[?(@.status.phase=="Running")].metadata.name}' That way only shows when pod is actually running and not pods in other states. – Rooted

Answer 1

Try this:

kubectl get pods --sort-by=.metadata.creationTimestamp -o jsonpath="{.items[0].metadata.name}"

Liv

Thx. Works with oc as well. – Cuddy

This returns the results in reverse order, how do I get the most recent pod, not the oldest pod? – Puduns

You can use jsonpath to get the last element in the result array. Instead of 0, use '-1:' kubectl get pods --sort-by=.metadata.creationTimestamp -o jsonpath="{.items[-1:].metadata.name}" – Highpowered

Answer 2

On Kubernetes front, kubectl get po --sort-by=.status.startTime is supposed to work, except in K8s 1.7: it was fixed for 1.8.

"Kubernetes sort pods by age" also mentions

kubectl get pods --sort-by=.metadata.creationTimestamp

Since Openshift 3.9 (March 2018) is fairly recent, those kubectl commands should work even if the oc one is not fully compatible.

Bodoni

Yes, but can kubectl return only the name of the one pod that it sorts last? For oc get pods --sort-by=.metadata.creationTimestamp I get a list of rows with columns NAME, READY, STATUS, RESTARTS, AGE, sorted by age. – Cuddy