toToml filter converts int to float

[dud225]

Given the following data structure in values.yaml:

config:
  bar: 9

And this in my configmap template:

data:
  telegraf-local.conf: |-
{{ .Values.config | toToml | indent 4 }}

I get this:

data:
  telegraf-local.conf: |-
    foo = 9.0

Even casting the variable via bar: !!int 9 doesn't change the behavior, can't reproduce using the toJson filter either.

I'm running Helm version.BuildInfo{Version:"v3.14.4", GitCommit:"81c902a123462fd4052bc5e9aa9c513c4c8fc142", GitTreeState:"clean", GoVersion:"go1.21.9"}

[gjenkins8]

toToml uses github.com/BurntSushi/toml to encode:

	e := toml.NewEncoder(b)
	err := e.Encode(v)

helm/pkg/engine/funcs.go

Lines 125 to 133 in c6beb16

	func toTOML(v interface{}) string {
	b := bytes.NewBuffer(nil)
	e := toml.NewEncoder(b)
	err := e.Encode(v)
	if err != nil {
	return err.Error()
	}
	return b.String()
	}

Either Helm is representing the value internally as float, and toToml is rendering that. Or the design decision/issue with rendering ints as floats lies upstream with github.com/BurntSushi/toml. The former should be determined first I think.

[johanfleury]

IIRC, the internal representation is float. #6010 was made to use json.Number but was then reverted.

It seems like the toml module supports json.Number: https://github.com/BurntSushi/toml/blob/77ce8589413d1fc280be524c8992599c42027c61/encode.go#L259-L272

[CalvinKrist]

I made a draft PR to demonstrate this (just an easy way to share code), but adding unit tests for the toToml function that test the int and float conversion makes it appear that BurntSushi is handling this correctly and the issue is likely elsewhere #13012. These tests pass locally for me.

[CalvinKrist]

That said, I did repro this issue. I did helm create to make a simple helm chart, added the following config map:

data:
  {{ .Values | toToml }}

copied their values:

bar: 9

and then helm template . returns:

---
# Source: mychart/templates/cm.yaml
data:
    bar = 9.0

I added this repro to my demo PR as a failing test in the template_test.go file.

[CalvinKrist]

I was able to trace this to the function yaml.Unmarshal from the sigs.k8s.io/yaml package, used on this line. When debugging the failing test I added to template_test.go, this loads the value as a flaot64 even though we can see it should be an int. Not sure how fixable this is since it's from an external dependency.