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hydra_oidc_poc/common/handlers/errors.go

138 lines
3.3 KiB
Go

package handlers
import (
"context"
"html/template"
"net/http"
"path"
"github.com/nicksnyder/go-i18n/v2/i18n"
log "github.com/sirupsen/logrus"
commonServices "git.cacert.org/oidc_login/common/services"
)
type errorKey int
const (
errorBucketKey errorKey = iota
)
type ErrorDetails struct {
ErrorMessage string
ErrorDetails []string
ErrorCode string
Error error
}
type ErrorBucket struct {
errorDetails *ErrorDetails
templates *template.Template
logger *log.Logger
bundle *i18n.Bundle
messageCatalog *commonServices.MessageCatalog
}
func (b *ErrorBucket) serveHTTP(w http.ResponseWriter, r *http.Request) {
if b.errorDetails != nil {
accept := r.Header.Get("Accept-Language")
localizer := i18n.NewLocalizer(b.bundle, accept)
err := b.templates.Lookup("base").Execute(w, map[string]interface{}{
"Title": b.messageCatalog.LookupMessage(
"ErrorTitle",
nil,
localizer,
),
"details": b.errorDetails,
})
if err != nil {
log.Errorf("error rendering error template: %v", err)
http.Error(
w,
http.StatusText(http.StatusInternalServerError),
http.StatusInternalServerError,
)
}
}
}
func GetErrorBucket(r *http.Request) *ErrorBucket {
return r.Context().Value(errorBucketKey).(*ErrorBucket)
}
// call this from your application's handler
func (b *ErrorBucket) AddError(details *ErrorDetails) {
b.errorDetails = details
}
type errorResponseWriter struct {
http.ResponseWriter
ctx context.Context
statusCode int
}
func (w *errorResponseWriter) WriteHeader(code int) {
w.statusCode = code
if code >= 400 {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
errorBucket := w.ctx.Value(errorBucketKey).(*ErrorBucket)
if errorBucket != nil && errorBucket.errorDetails == nil {
errorBucket.AddError(&ErrorDetails{
ErrorMessage: http.StatusText(code),
})
}
}
w.ResponseWriter.WriteHeader(code)
}
func (w *errorResponseWriter) Write(content []byte) (int, error) {
if w.statusCode > 400 {
errorBucket := w.ctx.Value(errorBucketKey).(*ErrorBucket)
if errorBucket != nil {
if errorBucket.errorDetails.ErrorDetails == nil {
errorBucket.errorDetails.ErrorDetails = make([]string, 0)
}
errorBucket.errorDetails.ErrorDetails = append(
errorBucket.errorDetails.ErrorDetails, string(content),
)
return len(content), nil
}
}
return w.ResponseWriter.Write(content)
}
func ErrorHandling(
handlerContext context.Context,
logger *log.Logger,
templateBaseDir string,
) (func(http.Handler) http.Handler, error) {
errorTemplates, err := template.ParseFiles(
path.Join(templateBaseDir, "base.gohtml"),
path.Join(templateBaseDir, "errors.gohtml"),
)
if err != nil {
return nil, err
}
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
errorBucket := &ErrorBucket{
templates: errorTemplates,
logger: logger,
bundle: commonServices.GetI18nBundle(handlerContext),
messageCatalog: commonServices.GetMessageCatalog(handlerContext),
}
ctx := context.WithValue(r.Context(), errorBucketKey, errorBucket)
interCeptingResponseWriter := &errorResponseWriter{
w,
ctx,
http.StatusOK,
}
next.ServeHTTP(
interCeptingResponseWriter,
r.WithContext(ctx),
)
errorBucket.serveHTTP(w, r)
})
}, nil
}