helm: The `helm pull` command does not remove temporarily index files from repository cache location

Helm pull uses a temporarily index file, which isn’t removed. As the cached index file is never reused, I guess it should be removed automatically by Helm.

Scenario: CD tools, like ArgoCD, run numerous helm pull commands which causes the cache directory size to grow. Depending on your ephemeral storage constraints this results in pods being evicted as they exceed the storage limits.

Output of helm version:

$ helm version
version.BuildInfo{Version:"v3.7.1", GitCommit:"1d11fcb5d3f3bf00dbe6fe31b8412839a96b3dc4", GitTreeState:"clean", GoVersion:"go1.16.9"}

Output of kubectl version: n/a

Cloud Provider/Platform (AKS, GKE, Minikube etc.): n/a

Check repository cache location:

$ helm repo
...
--repository-cache string     path to the file containing cached repository indexes (default "~/.cache/helm/repository")
...

Clean up cache folder and check it is empty:

$ ls -ah ~/.cache/helm/repository/
.   ..

Run a repo update:

$ helm repo update
...
Update Complete. *Happy Helming!*

Check our cache dir, all seems as expected:

$ ls -ah ~/.cache/helm/repository/
.  ..  stable-charts.txt  stable-index.yaml

Lets pull a chart (using bitnami/kafka here as example):

$ helm pull --version 14.9.1 --repo https://charts.bitnami.com/bitnami kafka
$ ls -ah
.  ..  kafka-14.9.1.tgz

Check our cache dir:

$ ls -ah ~/.cache/helm/repository/
.  ..  'deZbVF1bUWI1H+i+PNkPYPlhuxo=-charts.txt' 'deZbVF1bUWI1H+i+PNkPYPlhuxo=-index.yaml' stable-charts.txt  stable-index.yaml

Repeating the same helm pull command creates new cache files every time.