mirror of
https://github.com/TwiN/gatus.git
synced 2024-11-22 16:03:44 +01:00
320 lines
10 KiB
Go
320 lines
10 KiB
Go
package yaml
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
"reflect"
|
|
"strconv"
|
|
|
|
"gopkg.in/yaml.v2"
|
|
)
|
|
|
|
// Marshal marshals the object into JSON then converts JSON to YAML and returns the
|
|
// YAML.
|
|
func Marshal(o interface{}) ([]byte, error) {
|
|
j, err := json.Marshal(o)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("error marshaling into JSON: %v", err)
|
|
}
|
|
|
|
y, err := JSONToYAML(j)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("error converting JSON to YAML: %v", err)
|
|
}
|
|
|
|
return y, nil
|
|
}
|
|
|
|
// JSONOpt is a decoding option for decoding from JSON format.
|
|
type JSONOpt func(*json.Decoder) *json.Decoder
|
|
|
|
// Unmarshal converts YAML to JSON then uses JSON to unmarshal into an object,
|
|
// optionally configuring the behavior of the JSON unmarshal.
|
|
func Unmarshal(y []byte, o interface{}, opts ...JSONOpt) error {
|
|
return yamlUnmarshal(y, o, false, opts...)
|
|
}
|
|
|
|
// UnmarshalStrict strictly converts YAML to JSON then uses JSON to unmarshal
|
|
// into an object, optionally configuring the behavior of the JSON unmarshal.
|
|
func UnmarshalStrict(y []byte, o interface{}, opts ...JSONOpt) error {
|
|
return yamlUnmarshal(y, o, true, append(opts, DisallowUnknownFields)...)
|
|
}
|
|
|
|
// yamlUnmarshal unmarshals the given YAML byte stream into the given interface,
|
|
// optionally performing the unmarshalling strictly
|
|
func yamlUnmarshal(y []byte, o interface{}, strict bool, opts ...JSONOpt) error {
|
|
vo := reflect.ValueOf(o)
|
|
unmarshalFn := yaml.Unmarshal
|
|
if strict {
|
|
unmarshalFn = yaml.UnmarshalStrict
|
|
}
|
|
j, err := yamlToJSON(y, &vo, unmarshalFn)
|
|
if err != nil {
|
|
return fmt.Errorf("error converting YAML to JSON: %v", err)
|
|
}
|
|
|
|
err = jsonUnmarshal(bytes.NewReader(j), o, opts...)
|
|
if err != nil {
|
|
return fmt.Errorf("error unmarshaling JSON: %v", err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// jsonUnmarshal unmarshals the JSON byte stream from the given reader into the
|
|
// object, optionally applying decoder options prior to decoding. We are not
|
|
// using json.Unmarshal directly as we want the chance to pass in non-default
|
|
// options.
|
|
func jsonUnmarshal(r io.Reader, o interface{}, opts ...JSONOpt) error {
|
|
d := json.NewDecoder(r)
|
|
for _, opt := range opts {
|
|
d = opt(d)
|
|
}
|
|
if err := d.Decode(&o); err != nil {
|
|
return fmt.Errorf("while decoding JSON: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// JSONToYAML Converts JSON to YAML.
|
|
func JSONToYAML(j []byte) ([]byte, error) {
|
|
// Convert the JSON to an object.
|
|
var jsonObj interface{}
|
|
// We are using yaml.Unmarshal here (instead of json.Unmarshal) because the
|
|
// Go JSON library doesn't try to pick the right number type (int, float,
|
|
// etc.) when unmarshalling to interface{}, it just picks float64
|
|
// universally. go-yaml does go through the effort of picking the right
|
|
// number type, so we can preserve number type throughout this process.
|
|
err := yaml.Unmarshal(j, &jsonObj)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Marshal this object into YAML.
|
|
return yaml.Marshal(jsonObj)
|
|
}
|
|
|
|
// YAMLToJSON converts YAML to JSON. Since JSON is a subset of YAML,
|
|
// passing JSON through this method should be a no-op.
|
|
//
|
|
// Things YAML can do that are not supported by JSON:
|
|
// * In YAML you can have binary and null keys in your maps. These are invalid
|
|
// in JSON. (int and float keys are converted to strings.)
|
|
// * Binary data in YAML with the !!binary tag is not supported. If you want to
|
|
// use binary data with this library, encode the data as base64 as usual but do
|
|
// not use the !!binary tag in your YAML. This will ensure the original base64
|
|
// encoded data makes it all the way through to the JSON.
|
|
//
|
|
// For strict decoding of YAML, use YAMLToJSONStrict.
|
|
func YAMLToJSON(y []byte) ([]byte, error) {
|
|
return yamlToJSON(y, nil, yaml.Unmarshal)
|
|
}
|
|
|
|
// YAMLToJSONStrict is like YAMLToJSON but enables strict YAML decoding,
|
|
// returning an error on any duplicate field names.
|
|
func YAMLToJSONStrict(y []byte) ([]byte, error) {
|
|
return yamlToJSON(y, nil, yaml.UnmarshalStrict)
|
|
}
|
|
|
|
func yamlToJSON(y []byte, jsonTarget *reflect.Value, yamlUnmarshal func([]byte, interface{}) error) ([]byte, error) {
|
|
// Convert the YAML to an object.
|
|
var yamlObj interface{}
|
|
err := yamlUnmarshal(y, &yamlObj)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// YAML objects are not completely compatible with JSON objects (e.g. you
|
|
// can have non-string keys in YAML). So, convert the YAML-compatible object
|
|
// to a JSON-compatible object, failing with an error if irrecoverable
|
|
// incompatibilties happen along the way.
|
|
jsonObj, err := convertToJSONableObject(yamlObj, jsonTarget)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Convert this object to JSON and return the data.
|
|
return json.Marshal(jsonObj)
|
|
}
|
|
|
|
func convertToJSONableObject(yamlObj interface{}, jsonTarget *reflect.Value) (interface{}, error) {
|
|
var err error
|
|
|
|
// Resolve jsonTarget to a concrete value (i.e. not a pointer or an
|
|
// interface). We pass decodingNull as false because we're not actually
|
|
// decoding into the value, we're just checking if the ultimate target is a
|
|
// string.
|
|
if jsonTarget != nil {
|
|
ju, tu, pv := indirect(*jsonTarget, false)
|
|
// We have a JSON or Text Umarshaler at this level, so we can't be trying
|
|
// to decode into a string.
|
|
if ju != nil || tu != nil {
|
|
jsonTarget = nil
|
|
} else {
|
|
jsonTarget = &pv
|
|
}
|
|
}
|
|
|
|
// If yamlObj is a number or a boolean, check if jsonTarget is a string -
|
|
// if so, coerce. Else return normal.
|
|
// If yamlObj is a map or array, find the field that each key is
|
|
// unmarshaling to, and when you recurse pass the reflect.Value for that
|
|
// field back into this function.
|
|
switch typedYAMLObj := yamlObj.(type) {
|
|
case map[interface{}]interface{}:
|
|
// JSON does not support arbitrary keys in a map, so we must convert
|
|
// these keys to strings.
|
|
//
|
|
// From my reading of go-yaml v2 (specifically the resolve function),
|
|
// keys can only have the types string, int, int64, float64, binary
|
|
// (unsupported), or null (unsupported).
|
|
strMap := make(map[string]interface{})
|
|
for k, v := range typedYAMLObj {
|
|
// Resolve the key to a string first.
|
|
var keyString string
|
|
switch typedKey := k.(type) {
|
|
case string:
|
|
keyString = typedKey
|
|
case int:
|
|
keyString = strconv.Itoa(typedKey)
|
|
case int64:
|
|
// go-yaml will only return an int64 as a key if the system
|
|
// architecture is 32-bit and the key's value is between 32-bit
|
|
// and 64-bit. Otherwise the key type will simply be int.
|
|
keyString = strconv.FormatInt(typedKey, 10)
|
|
case float64:
|
|
// Stolen from go-yaml to use the same conversion to string as
|
|
// the go-yaml library uses to convert float to string when
|
|
// Marshaling.
|
|
s := strconv.FormatFloat(typedKey, 'g', -1, 32)
|
|
switch s {
|
|
case "+Inf":
|
|
s = ".inf"
|
|
case "-Inf":
|
|
s = "-.inf"
|
|
case "NaN":
|
|
s = ".nan"
|
|
}
|
|
keyString = s
|
|
case bool:
|
|
if typedKey {
|
|
keyString = "true"
|
|
} else {
|
|
keyString = "false"
|
|
}
|
|
default:
|
|
return nil, fmt.Errorf("Unsupported map key of type: %s, key: %+#v, value: %+#v",
|
|
reflect.TypeOf(k), k, v)
|
|
}
|
|
|
|
// jsonTarget should be a struct or a map. If it's a struct, find
|
|
// the field it's going to map to and pass its reflect.Value. If
|
|
// it's a map, find the element type of the map and pass the
|
|
// reflect.Value created from that type. If it's neither, just pass
|
|
// nil - JSON conversion will error for us if it's a real issue.
|
|
if jsonTarget != nil {
|
|
t := *jsonTarget
|
|
if t.Kind() == reflect.Struct {
|
|
keyBytes := []byte(keyString)
|
|
// Find the field that the JSON library would use.
|
|
var f *field
|
|
fields := cachedTypeFields(t.Type())
|
|
for i := range fields {
|
|
ff := &fields[i]
|
|
if bytes.Equal(ff.nameBytes, keyBytes) {
|
|
f = ff
|
|
break
|
|
}
|
|
// Do case-insensitive comparison.
|
|
if f == nil && ff.equalFold(ff.nameBytes, keyBytes) {
|
|
f = ff
|
|
}
|
|
}
|
|
if f != nil {
|
|
// Find the reflect.Value of the most preferential
|
|
// struct field.
|
|
jtf := t.Field(f.index[0])
|
|
strMap[keyString], err = convertToJSONableObject(v, &jtf)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
continue
|
|
}
|
|
} else if t.Kind() == reflect.Map {
|
|
// Create a zero value of the map's element type to use as
|
|
// the JSON target.
|
|
jtv := reflect.Zero(t.Type().Elem())
|
|
strMap[keyString], err = convertToJSONableObject(v, &jtv)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
continue
|
|
}
|
|
}
|
|
strMap[keyString], err = convertToJSONableObject(v, nil)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return strMap, nil
|
|
case []interface{}:
|
|
// We need to recurse into arrays in case there are any
|
|
// map[interface{}]interface{}'s inside and to convert any
|
|
// numbers to strings.
|
|
|
|
// If jsonTarget is a slice (which it really should be), find the
|
|
// thing it's going to map to. If it's not a slice, just pass nil
|
|
// - JSON conversion will error for us if it's a real issue.
|
|
var jsonSliceElemValue *reflect.Value
|
|
if jsonTarget != nil {
|
|
t := *jsonTarget
|
|
if t.Kind() == reflect.Slice {
|
|
// By default slices point to nil, but we need a reflect.Value
|
|
// pointing to a value of the slice type, so we create one here.
|
|
ev := reflect.Indirect(reflect.New(t.Type().Elem()))
|
|
jsonSliceElemValue = &ev
|
|
}
|
|
}
|
|
|
|
// Make and use a new array.
|
|
arr := make([]interface{}, len(typedYAMLObj))
|
|
for i, v := range typedYAMLObj {
|
|
arr[i], err = convertToJSONableObject(v, jsonSliceElemValue)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return arr, nil
|
|
default:
|
|
// If the target type is a string and the YAML type is a number,
|
|
// convert the YAML type to a string.
|
|
if jsonTarget != nil && (*jsonTarget).Kind() == reflect.String {
|
|
// Based on my reading of go-yaml, it may return int, int64,
|
|
// float64, or uint64.
|
|
var s string
|
|
switch typedVal := typedYAMLObj.(type) {
|
|
case int:
|
|
s = strconv.FormatInt(int64(typedVal), 10)
|
|
case int64:
|
|
s = strconv.FormatInt(typedVal, 10)
|
|
case float64:
|
|
s = strconv.FormatFloat(typedVal, 'g', -1, 32)
|
|
case uint64:
|
|
s = strconv.FormatUint(typedVal, 10)
|
|
case bool:
|
|
if typedVal {
|
|
s = "true"
|
|
} else {
|
|
s = "false"
|
|
}
|
|
}
|
|
if len(s) > 0 {
|
|
yamlObj = interface{}(s)
|
|
}
|
|
}
|
|
return yamlObj, nil
|
|
}
|
|
}
|