cloudfoundry/cf-k8s-controllers

package validation

import (
    "encoding/json"
    "errors"
    "net/http"

    k8serrors "k8s.io/apimachinery/pkg/api/errors"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

const (
    UnknownErrorType                   = "UnknownError"
    UnknownErrorMessage                = "An unknown error has occurred"
    ImmutableFieldErrorType            = "ImmutableFieldError"
    ImmutableFieldErrorMessageTemplate = "'%s' field is immutable"
)

type ValidationError struct {
    Type    string `json:"validationErrorType"`
    Message string `json:"message"`
}

func (v ValidationError) Error() string {
    return "ValidationError-" + v.Type + ": " + v.Message
}

func (v ValidationError) GetMessage() string {
    return v.Message
}

func (v ValidationError) ExportJSONError() error {
    bytes, err := json.Marshal(v)
    if err != nil { // This (probably) can't fail, untested
        return err
    }

    return &k8serrors.StatusError{
        ErrStatus: metav1.Status{
            Reason: metav1.StatusReason(bytes),
            Code:   http.StatusForbidden,
        },
    }
}

func WebhookErrorToValidationError(err error) (ValidationError, bool) {
    statusErr := new(k8serrors.StatusError)
    if !errors.As(err, &statusErr) {
        return ValidationError{}, false
    }

    validationErr := new(ValidationError)
    if err := json.Unmarshal([]byte(statusErr.Status().Reason), validationErr); err != nil {
        return ValidationError{}, false
    }

    return *validationErr, true
}