agent-orchestrator/backend/internal/httpd/envelope/envelope.go

95 lines
3.3 KiB
Go

package envelope
import (
"context"
"encoding/json"
"errors"
"net/http"
"github.com/go-chi/chi/v5/middleware"
"github.com/aoagents/agent-orchestrator/backend/internal/httpd/apierr"
)
// errCapture is a request-scoped slot WriteError records the raw service error
// into. The wire envelope deliberately hides internals behind "Internal server
// error", which previously meant a 500's cause was lost entirely — the access
// log reads the captured error back so the daemon log keeps the diagnosis.
type errCapture struct{ err error }
type errCaptureKey struct{}
// WithErrorCapture returns a copy of the request whose context carries an
// error-capture slot, plus a getter for the error recorded by WriteError while
// handling it. The request logger installs it and reads it after the handler.
func WithErrorCapture(r *http.Request) (*http.Request, func() error) {
capture := &errCapture{}
req := r.WithContext(context.WithValue(r.Context(), errCaptureKey{}, capture))
return req, func() error { return capture.err }
}
// captureError records err for the request if a capture slot is present.
func captureError(r *http.Request, err error) {
if c, ok := r.Context().Value(errCaptureKey{}).(*errCapture); ok {
c.err = err
}
}
// APIError is the locked wire shape for every non-2xx response.
type APIError struct {
Error string `json:"error"`
Code string `json:"code"`
Message string `json:"message"`
RequestID string `json:"requestId,omitempty"`
Details map[string]any `json:"details,omitempty"`
}
// WriteJSON serialises v as JSON with the given status.
func WriteJSON(w http.ResponseWriter, status int, v any) {
w.Header().Set("Content-Type", "application/json; charset=utf-8")
w.WriteHeader(status)
_ = json.NewEncoder(w).Encode(v)
}
// WriteAPIError emits the locked envelope for any non-2xx response.
func WriteAPIError(w http.ResponseWriter, r *http.Request, status int, kind, code, message string, details map[string]any) {
WriteJSON(w, status, APIError{
Error: kind,
Code: code,
Message: message,
RequestID: middleware.GetReqID(r.Context()),
Details: details,
})
}
// WriteError is the single path from any service error to the wire envelope. It
// renders an *apierr.Error (anywhere in the chain) using its Kind, and falls
// back to a 500 for any other error so internal details never leak. This is the
// only place an apierr.Kind is translated into an HTTP status and wire word.
func WriteError(w http.ResponseWriter, r *http.Request, err error) {
captureError(r, err)
var e *apierr.Error
if errors.As(err, &e) {
status, kind := httpStatus(e.Kind)
WriteAPIError(w, r, status, kind, e.Code, e.Message, e.Details)
return
}
WriteAPIError(w, r, http.StatusInternalServerError, "internal", "INTERNAL_ERROR", "Internal server error", nil)
}
// httpStatus maps a semantic failure Kind to its HTTP status and wire word.
func httpStatus(k apierr.Kind) (int, string) {
switch k {
case apierr.KindInvalid:
return http.StatusBadRequest, "bad_request"
case apierr.KindNotFound:
return http.StatusNotFound, "not_found"
case apierr.KindConflict:
return http.StatusConflict, "conflict"
case apierr.KindInternal:
return http.StatusInternalServerError, "internal"
default:
return http.StatusInternalServerError, "internal"
}
}