2

I have a total of 2030 pvc's and I want to delete 2000 pvc's form them and keep the 30.

  • Those 30 pvc's are latest and only less that 2 days old.. so that is why I do not want to delete them. The other all 2000 pvc are more than 2 days old.

  • I want to create a script that runs automatically to delete the pvc's which are more than 2 days old.

some example of my pvcs:

NAME                            STATUS        VOLUME    CAPACITY   ACCESS MODES   STORAGECLASS   AGE
data-14353-postgresql-0         Bound         pvc-1a6   8Gi        RWO            gp2            2d15h
data-14354-postgresql-0         Bound         pvc-2d6   8Gi        RWO            gp2            16d
data-14358-postgresql-0         Bound         pvc-9dc   8Gi        RWO            gp2            127m
data-14367-postgresql-0         Bound         pvc-2eb   8Gi        RWO            gp2            65h
data-14370-postgresql-0         Bound         pvc-90d   8Gi        RWO            gp2            56d

now as u can see I have a mixed AGE label.

They can be deleted using:

kubectl delete pvc

but this will delete all.. and I do not want to delete all!

  • what command or -label for age I can add to run the command to delete all pvc except those with less than 2 days old.
Jonas
  • 121,568
  • 97
  • 310
  • 388
devgirl
  • 671
  • 3
  • 16
  • 39

2 Answers2

4

TL:DR;

kubectl get pvc --sort-by=.metadata.creationTimestamp --no-headers | tac | cut -d ' ' -f 1 | sed -n 31,2000p | xargs kubectl delete pvc

Let's explain in pieces:

  • kubectl get pvc --sort-by=.metadata.creationTimestamp --no-headers:

    This part lists the PVCs in descending order without the header row

  • tac

    reverse the output and produce ascending order

  • cut -d ' ' -f 1

    Get's the first column which have the PVCs names

  • sed -n 31,2000p

    Prints all the PVCs after line 30 which will contain your 30 PVCs which are less that 2 days old

    p - Print out the pattern space (to the standard output). This command is usually only used in conjunction with the -n command-line option.

    n - If auto-print is not disabled, print the pattern space, then, regardless, replace the pattern space with the next line of input. If there is no more input then sed exits without processing any more commands.

  • xargs kubectl delete pvc

Deletes your PVCs.

0xMH
  • 1,825
  • 20
  • 26
  • thank u.. can pls just elaborate on the "sed -n 31,p2000" part. like what does 'sed" mean and "-n" mean? and the "p" before 2000? thanks again – devgirl Feb 02 '21 at 05:19
  • Updated my answer. Please check it now. – 0xMH Feb 02 '21 at 11:39
  • also a follow up question: what if my pvc number changes? like its not 2000 anymore? can it be an automated way/command to only pick the more than 2 days old pvc and only delete those? ... also this whole command deletes the 2000 pvc right? – devgirl Feb 03 '21 at 07:30
  • If your pvc number changes then you change the sed ranges. That's the best that I can think of in regarding the CLI tools. You can improve it a lot if you use a real programming language and talked to k8s api – 0xMH Feb 03 '21 at 09:33
2

There is no easy way to do this by just using a kubectl command, its only easy to operate that way when you can use labels in a good way.

But you can do this programmatically, by using a programming or scripting language against the Kubernetes API Server.

Perhaps, you can in this case, manually add a label to the 30 PVCs that you want to keep, and then delete the PVCs which does not have this label.

If you have managed to label the PVCs that you want to keep, you can use e.g.

 kubectl delete pvc -l !keep

See more about how to add labels and select resources using labels on Labels and Selectors

Jonas
  • 121,568
  • 97
  • 310
  • 388