/
utils.go
62 lines (58 loc) · 1.57 KB
/
utils.go
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package k8s
import (
"errors"
"fmt"
"reflect"
"regexp"
"strconv"
"strings"
"github.com/fatih/structs"
)
var (
sliceRe = regexp.MustCompile(`([^\[\]]+)\[(\d+)\]$`)
)
func CompareAndUpdateStructField(o any, path []string, setValue string) (string, bool, error) {
if len(path) == 0 {
return "", false, errors.New("no path specified")
}
fields := structs.Fields(o)
lookForTag := path[0]
wantSlice := false
var sliceIndex uint64
if match := sliceRe.FindStringSubmatch(lookForTag); match != nil {
var err error
sliceIndex, err = strconv.ParseUint(match[2], 10, 64)
if err != nil {
return "", false, fmt.Errorf("failed to parse slice index '%s' to uint64, err: %v", match[2], err)
}
wantSlice = true
lookForTag = match[1]
}
for _, f := range fields {
sp := strings.Split(f.Tag("json"), ",")
tag := sp[0]
if tag != lookForTag {
continue
}
if len(path) == 1 {
if wantSlice {
return "", false, errors.New("directly setting a slice element is not supported")
}
oldVal := f.Value().(string)
if setValue == oldVal {
return oldVal, false, nil
}
return oldVal, true, f.Set(setValue)
}
var obj any = f.Value()
if wantSlice {
if f.Kind() != reflect.Slice {
return "", false, fmt.Errorf("expected '%s' to be a slice, got %s instead", lookForTag, f.Kind().String())
}
obj = reflect.ValueOf(f.Value()).Index(int(sliceIndex)).Addr().Interface()
}
newPath := path[1:]
return CompareAndUpdateStructField(obj, newPath, setValue)
}
return "", false, fmt.Errorf("could not find field with JSON tag %s in object %+v", lookForTag, o)
}