Answer my own question

I have a bunch of pods in kubernetes which are completed (successfully or unsuccessfully) and I'd like to clean up the output of kubectl get pods. Here's what I see when I run kubectl get pods:

NAME READY STATUS RESTARTS AGE
intent-insights-aws-org-73-ingest-391c9384 0/1 ImagePullBackOff 0 8d
intent-postgres-f6dfcddcc-5qwl7 1/1 Running 0 23h
redis-scheduler-dev-master-0 1/1 Running 0 10h
redis-scheduler-dev-metrics-85b45bbcc7-ch24g 1/1 Running 0 6d
redis-scheduler-dev-slave-74c7cbb557-dmvfg 1/1 Running 0 10h
redis-scheduler-dev-slave-74c7cbb557-jhqwx 1/1 Running 0 5d
scheduler-5f48b845b6-d5p4s 2/2 Running 0 36m
snapshot-169-5af87b54 0/1 Completed 0 20m
snapshot-169-8705f77c 0/1 Completed 0 1h
snapshot-169-be6f4774 0/1 Completed 0 1h
snapshot-169-ce9a8946 0/1 Completed 0 1h
snapshot-169-d3099b06 0/1 ImagePullBackOff 0 24m
snapshot-204-50714c88 0/1 Completed 0 21m
snapshot-204-7c86df5a 0/1 Completed 0 1h
snapshot-204-87f35e36 0/1 ImagePullBackOff 0 26m
snapshot-204-b3a4c292 0/1 Completed 0 1h
snapshot-204-c3d90db6 0/1 Completed 0 1h
snapshot-245-3c9a7226 0/1 ImagePullBackOff 0 28m
snapshot-245-45a907a0 0/1 Completed 0 21m
snapshot-245-71911b06 0/1 Completed 0 1h
snapshot-245-a8f5dd5e 0/1 Completed 0 1h
snapshot-245-b9132236 0/1 Completed 0 1h
snapshot-76-1e515338 0/1 Completed 0 22m
snapshot-76-4a7d9a30 0/1 Completed 0 1h
snapshot-76-9e168c9e 0/1 Completed 0 1h
snapshot-76-ae510372 0/1 Completed 0 1h
snapshot-76-f166eb18 0/1 ImagePullBackOff 0 30m
train-169-65f88cec 0/1 Error 0 20m
train-169-9c92f72a 0/1 Error 0 1h
train-169-c935fc84 0/1 Error 0 1h
train-169-d9593f80 0/1 Error 0 1h
train-204-70729e42 0/1 Error 0 20m
train-204-9203be3e 0/1 Error 0 1h
train-204-d3f2337c 0/1 Error 0 1h
train-204-e41a3e88 0/1 Error 0 1h
train-245-7b65d1f2 0/1 Error 0 19m
train-245-a7510d5a 0/1 Error 0 1h
train-245-debf763e 0/1 Error 0 1h
train-245-eec1908e 0/1 Error 0 1h
train-76-86381784 0/1 Completed 0 19m
train-76-b1fdc202 0/1 Error 0 1h
train-76-e972af06 0/1 Error 0 1h
train-76-f993c8d8 0/1 Completed 0 1h
webserver-7fc9c69f4d-mnrjj 2/2 Running 0 36m
worker-6997bf76bd-kvjx4 2/2 Running 0 25m
worker-6997bf76bd-prxbg 2/2 Running 0 36m

and I'd like to get rid of the pods like train-204-d3f2337c. How can I do that?

If this pods created by CronJob, you can use spec.failedJobsHistoryLimit and spec.successfulJobsHistoryLimit

Example:

apiVersion: batch/v1beta1
kind: CronJob
metadata:
 name: my-cron-job
spec:
 schedule: "*/10 * * * *"
 failedJobsHistoryLimit: 1
 successfulJobsHistoryLimit: 3
 jobTemplate:
 spec:
 template:
 ...

Here's a one liner which will delete all pods which aren't in the Running or Pending state (note that if a pod name has Running or Pending in it, it won't get deleted ever with this one liner):

kubectl get pods --no-headers=true |grep -v "Running" | grep -v "Pending" | sed -E 's/([a-z0-9-]+).*/1/g' | xargs kubectl delete pod

Here's an explanation:

1. get all pods without any of the headers


2. filter out pods which are Running
   


3. filter out pods which are Pending
   


4. pull out the name of the pod using a sed regex


5. use xargs to delete each of the pods by name

Note, this doesn't account for all pod states. For example, if a pod is in the state ContainerCreating this one liner will delete that pod too.