chart2kro
Documentation menu

Go library

Use chart2kro from Go: Convert, Inspect, Validate, Diff and Instance in the pkg/chart2kro package, with the same results as the CLI.

go get github.com/hupe1980/chart2kro

The CLI is a thin client of pkg/chart2kro: the library produces exactly the CLI's output.

import "github.com/hupe1980/chart2kro/pkg/chart2kro"

res, err := chart2kro.Convert(ctx, chart2kro.Options{
    Chart:      "oci://ghcr.io/stefanprodan/charts/podinfo",
    Version:    "6.15.0",
    ValueFiles: []string{"platform-defaults.yaml"},
    Expose:     []string{"replicaCount", "image.tag"},
    Group:      "apps.example.com",
})
if err != nil {
    os.Exit(chart2kro.ExitCode(err)) // same codes as the CLI
}

os.WriteFile("rgd.yaml", res.RGD, 0o644)
// res.Prerequisites: CRDs and shared cluster objects (may be empty)
// res.Instance:      an example instance
// res.Report:        every value with its outcome and reason

API

Function
Convert(ctx, Options) (*Result, error)Convert a chart
Inspect(ctx, Options) (*Report, error)Convert and return only the report
Validate(ctx, yamlStream, ValidateOptions) errorValidate RGDs offline with kro's own checks
Diff(existing, updated []byte) (*DiffResult, error)Classify API changes (breaking, destructive, compatible). Inputs may be YAML streams; each must contain exactly one RGD. JSON schema chart2kro.io/diff/v1
Instance(ctx, Options, InstanceOptions) ([]byte, error)Helm values to an instance manifest
ExitCode(err) intMap errors to the CLI's exit codes

Options

Options mirrors the CLI flags; the zero value means Helm's defaults. The fields you will use most:

FieldFlag
Chart, Version, RepoURLCHART, --version, --repo
ValueFiles, Set, SetString, SetFile-f, --set, --set-string, --set-file
Kind, Group, APIVersion--kind, --group, --api-version
Expose, Freeze--expose, --freeze
Exclude, ExcludeSubcharts, IncludeHooks--exclude, --exclude-subchart, --include-hooks
KubeVersion, CRDFiles--kube-version, --crd
Logger--log-level: a *slog.Logger for progress logs (default: discard)

The full list is on pkg.go.dev.

Errors

Errors wrap sentinel values, so test them with errors.Is: ErrUsage, ErrLoad, ErrRender, ErrConstraint, ErrWrite, ErrInvalid, ErrBreaking, ErrStale. ExitCode maps them to the CLI's exit codes.