Tips and Tricks: Fetch K8S Resources

Monday, Oct 4, 2021 17:00 · 231 words · 2 minutes read

Tips and Tricks

this blog post will be updated in the future with different scenarios

Overview

In this blog post I will demonstrate how to fetch K8S resources based on different criteria.

Select resources older than X time

Problem: I would like to list all statefulsets created more than 20 days ago

# the time is in seconds 1728000 seconds are 20 days
kubectl get statefulsets -o json | jq -r "[.items[] | {name: .metadata.name, startTime: .metadata.creationTimestamp | fromdate } | select(.startTime < (now | . - 1728000))]" | jq -r ".[].name"

Output:

mongo
redis

Problem: I would like to delete all namespaces older than 48 hours

# the time is in seconds 172800 seconds are 48 hours
kubectl get ns -o json | jq -r "[.items[] | {name: .metadata.name, startTime: .metadata.creationTimestamp | fromdate } | select(.startTime < (now | . - 172800))]" | jq -r ".[].name" | grep "build" | awk '{system("kubectl delete ns --force --grace-period=0 " $1)}'

warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
namespace "testable38be9171-6078-4611-8471-96f88e179298" force deleted
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
namespace "testable0d6abfc9-b647-4de5-a2b1-732c343e2dfe" force deleted