formatting changes introduced by eval

[frankfarzan]

kpt pkg get https://github.com/GoogleContainerTools/kpt.git/package-examples/wordpress@next
cd wordpress
kpt fn render
kpt fn eval --image gcr.io/kpt-fn/set-namespace:v0.1 -- namespace=wordpress
git diff

Two issues:

1. Why is set-namespace changing the formatting?
2. More importantly: This is a general issue that can happen with arbitrary functions. The current answer is that you should run render after eval. But then, why not just have eval perform formatting as well as a convenience?

[phanimarupaka]

This is an issue with the kyaml version being used by functions. set-labels set-namespace for instance are having this problem as they are using older version of kyaml. https://github.com/GoogleContainerTools/kpt-functions-catalog/blob/master/functions/go/set-namespace/go.mod#L8

apply-setters, search-replace work fine.

@mengqiy @droot I think we should have consistent usage of kyaml all across the functions. This is not just a problem with formatting but results in general.

This doesn't justify formatting resources by default as part of eval command as eval can be invoked on validation functions like kubeval, seeing formatting related diffs for invoking validator functions is scary.

[frankfarzan]

But you can have a pipeline with just a validator and render would format?

Not all functions are or will be using Go or kyaml, so the general question about formatting by eval is orthogonal.

[phanimarupaka]

But you can have a pipeline with just a validator and render would format?

Not all functions are or will be using Go or kyaml, so the general question about formatting by eval is orthogonal.

So you say we should format resources as part of eval as well ?

[phanimarupaka]

But you can have a pipeline with just a validator and render would format?

Not all functions are or will be using Go or kyaml, so the general question about formatting by eval is orthogonal.

Agree. So how about formatting resources as part of eval command as with clear messaging. In the following example, search(without replace) is formatting resources with clear messaging.

$ kpt fn eval --image gcr.io/kpt-fn/search-replace:v0.1 -- by-value=4

[RUNNING] "gcr.io/kpt-fn/search-replace:v0.1"
[PASS] "gcr.io/kpt-fn/search-replace:v0.1"
  Results:
    [INFO] Matched field value to "4" in file "resources.yaml" in field "spec.replicas"
    [INFO] Formatted resources.