cloudfoundry-incubator/stratos

package interfaces

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"

    "github.com/labstack/echo/v4"
)

type ErrHTTPShadow struct {
    HTTPError       *echo.HTTPError
    LogMessage      string
    UserFacingError string
}

type ErrHTTPRequest struct {
    Status     int
    InnerError error
    Response   string
}

type ErrorResponseBody struct {
    Status string `json:"status"`
    Error  string `json:"error"`
}

func (e ErrHTTPShadow) Error() string {
    return fmt.Sprintf("HTTP Error: %v\nLog Message: %s", e.HTTPError, e.LogMessage)
}

func NewHTTPError(status int, userFacingError string) error {
    return NewHTTPShadowError(status, userFacingError, "")
}

func NewHTTPShadowError(status int, userFacingError string, fmtString string, args ...interface{}) error {
    //Only set the HTTPError field of the ErrHTTPShadow struct if we have been passed an error message intended for logging
    httpErrorMsg := ""
    if len(userFacingError) > 0 {
        errBody := ErrorResponseBody{Status: "error", Error: userFacingError}
        bytes, _ := json.Marshal(errBody)
        httpErrorMsg = string(bytes)
    }
    shadowError := ErrHTTPShadow{
        UserFacingError: userFacingError,
        HTTPError:       echo.NewHTTPError(status, httpErrorMsg),
    }
    if args != nil {
        shadowError.LogMessage = fmt.Sprintf(fmtString, args...)
    }
    return shadowError
}

func (e ErrHTTPRequest) Error() string {
    body := "No request body"
    if len(e.Response) != 0 {
        body = e.Response
    }
    return fmt.Sprintf("Error: %v\nStatus: %d\nResponse: %s", e.InnerError, e.Status, body)
}

func LogHTTPError(r *http.Response, innerErr error) error {
    b := []byte("No request body")
    status := 0
    if r != nil {
        defer r.Body.Close()
        if bb, err := ioutil.ReadAll(r.Body); err == nil {
            b = bb
        }
        status = r.StatusCode
    }

    return ErrHTTPRequest{
        Status:     status,
        InnerError: innerErr,
        Response:   string(b),
    }

}