cmd/config set: Support for setting fields imperatively from the cli

kyaml/fieldmeta/fieldmeta.go

@@ -0,0 +1,134 @@
+package fieldmeta
+
+import (
+	"bytes"
+	"encoding/json"
+	"strconv"
+	"strings"
+
+	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// FieldMeta contains metadata that may be attached to fields as comments
+type FieldMeta struct {
+	// Substitutions are substitutions that may be performed against this field
+	Substitutions []Substitution `yaml:"substitutions,omitempty" json:"substitutions,omitempty"`
+	// OwnedBy records the owner of this field
+	OwnedBy string `yaml:"ownedBy,omitempty" json:"ownedBy,omitempty"`
+	// DefaultedBy records that this field was default, but may be changed by other owners
+	DefaultedBy string `yaml:"defaultedBy,omitempty" json:"defaultedBy,omitempty"`
+	// Description is a description of the current field value, e.g. why it was set
+	Description string `yaml:"description,omitempty" json:"description,omitempty"`
+	// Type is the type of the field value
+	Type FieldValueType `yaml:"type,omitempty" json:"type,omitempty"`
+}
+
+// Substitution defines a substitution that may be performed against the field
+type Substitution struct {
+	// Name is the name of the substitution and read by tools
+	Name string `yaml:"name,omitempty" json:"name,omitempty"`
+	// Marker is the marker used for replacement
+	Marker string `yaml:"marker,omitempty" json:"marker,omitempty"`
+	// Value is the current value that has been substituted for the Marker
+	Value string `yaml:"value,omitempty" json:"value,omitempty"`
+}
+
+// Read reads the FieldMeta from a node
+func (fm *FieldMeta) Read(n *yaml.RNode) error {
+	if n.YNode().LineComment != "" {
+		v := strings.TrimLeft(n.YNode().LineComment, "#")
+		// if it doesn't Unmarshal that is fine, it means there is no metadata
+		// other comments are valid, they just don't parse
+		d := yaml.NewDecoder(bytes.NewBuffer([]byte(v)))
+		d.KnownFields(false)
+		_ = d.Decode(fm)
+	}
+	return nil
+}
+
+// Write writes the FieldMeta to a node
+func (fm *FieldMeta) Write(n *yaml.RNode) error {
+	b, err := json.Marshal(fm)
+	if err != nil {
+		return err
+	}
+	n.YNode().LineComment = string(b)
+	return nil
+}
+
+// FieldValueType defines the type of input to register
+type FieldValueType string
+
+const (
+	// String defines a string flag
+	String FieldValueType = "string"
+	// Bool defines a bool flag
+	Bool = "bool"
+	// Float defines a float flag
+	Float = "float"
+	// Int defines an int flag
+	Int = "int"
+)
+
+func (it FieldValueType) String() string {
+	if it == "" {
+		return "string"
+	}
+	return string(it)
+}
+
+func (it FieldValueType) Validate(value string) error {
+	switch it {
+	case Int:
+		if _, err := strconv.Atoi(value); err != nil {
+			return errors.WrapPrefixf(err, "value must be an int")
+		}
+	case Bool:
+		if _, err := strconv.ParseBool(value); err != nil {
+			return errors.WrapPrefixf(err, "value must be a bool")
+		}
+	case Float:
+		if _, err := strconv.ParseFloat(value, 64); err != nil {
+			return errors.WrapPrefixf(err, "value must be a float")
+		}
+	}
+	return nil
+}
+
+func (it FieldValueType) Tag() string {
+	switch it {
+	case String:
+		return "!!str"
+	case Bool:
+		return "!!bool"
+	case Int:
+		return "!!int"
+	case Float:
+		return "!!float"
+	}
+	return ""
+}
+
+func (it FieldValueType) TagForValue(value string) string {
+	switch it {
+	case String:
+		return "!!str"
+	case Bool:
+		if _, err := strconv.ParseBool(string(it)); err != nil {
+			return ""
+		}
+		return "!!bool"
+	case Int:
+		if _, err := strconv.ParseInt(string(it), 0, 32); err != nil {
+			return ""
+		}
+		return "!!int"
+	case Float:
+		if _, err := strconv.ParseFloat(string(it), 64); err != nil {
+			return ""
+		}
+		return "!!float"
+	}
+	return ""
+}