arttor/helmify

package helmify

import (
    "dario.cat/mergo"
    "fmt"
    "strconv"
    "strings"

    "github.com/iancoleman/strcase"

    "k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
)

// Values - represents helm template values.yaml.
type Values map[string]interface{}

// Merge given values with current instance.
func (v *Values) Merge(values Values) error {
    if err := mergo.Merge(v, values, mergo.WithAppendSlice); err != nil {
        return fmt.Errorf("%w: unable to merge helm values", err)
    }
    return nil
}

// Add - adds given value to values and returns its helm template representation {{ .Values.<valueName> }}
func (v *Values) Add(value interface{}, name ...string) (string, error) {
    name = toCamelCase(name)
    switch val := value.(type) {
    case int:
        value = int64(val)
    case int8:
        value = int64(val)
    case int16:
        value = int64(val)
    case int32:
        value = int64(val)
    }

    err := unstructured.SetNestedField(*v, value, name...)
    if err != nil {
        return "", fmt.Errorf("%w: unable to set value: %v", err, name)
    }
    _, isString := value.(string)
    if isString {
        return "{{ .Values." + strings.Join(name, ".") + " | quote }}", nil
    }
    _, isSlice := value.([]interface{})
    if isSlice {
        spaces := strconv.Itoa(len(name) * 2)
        return "{{ toYaml .Values." + strings.Join(name, ".") + " | nindent " + spaces + " }}", nil
    }
    return "{{ .Values." + strings.Join(name, ".") + " }}", nil
}

// AddYaml - adds given value to values and returns its helm template representation as Yaml {{ .Values.<valueName> | toYaml | indent i }}
// indent  <= 0 will be omitted.
func (v *Values) AddYaml(value interface{}, indent int, newLine bool, name ...string) (string, error) {
    name = toCamelCase(name)
    err := unstructured.SetNestedField(*v, value, name...)
    if err != nil {
        return "", fmt.Errorf("%w: unable to set value: %v", err, name)
    }
    if indent > 0 {
        if newLine {
            return "{{ .Values." + strings.Join(name, ".") + fmt.Sprintf(" | toYaml | nindent %d }}", indent), nil
        }
        return "{{ .Values." + strings.Join(name, ".") + fmt.Sprintf(" | toYaml | indent %d }}", indent), nil
    }
    return "{{ .Values." + strings.Join(name, ".") + " | toYaml }}", nil
}

// AddSecret - adds empty value to values and returns its helm template representation {{ required "<valueName>" .Values.<valueName> }}.
// Set toBase64=true for Secret data to be base64 encoded and set false for Secret stringData.
func (v *Values) AddSecret(toBase64 bool, name ...string) (string, error) {
    name = toCamelCase(name)
    nameStr := strings.Join(name, ".")
    err := unstructured.SetNestedField(*v, "", name...)
    if err != nil {
        return "", fmt.Errorf("%w: unable to set value: %v", err, nameStr)
    }
    res := fmt.Sprintf(`{{ required "%[1]s is required" .Values.%[1]s`, nameStr)
    if toBase64 {
        res += " | b64enc"
    }
    return res + " | quote }}", err
}

func toCamelCase(name []string) []string {
    for i, n := range name {
        camelCase := strcase.ToLowerCamel(n)
        if n == strings.ToUpper(n) {
            camelCase = strcase.ToLowerCamel(strings.ToLower(n))
        }
        name[i] = camelCase
    }
    return name
}