248 lines
7.1 KiB
Go
248 lines
7.1 KiB
Go
package customerrors
|
|
|
|
import (
|
|
"bufio"
|
|
"bytes"
|
|
"context"
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
"net/url"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/containous/traefik/old/types"
|
|
"github.com/containous/traefik/pkg/config"
|
|
"github.com/containous/traefik/pkg/middlewares"
|
|
"github.com/containous/traefik/pkg/tracing"
|
|
"github.com/opentracing/opentracing-go/ext"
|
|
"github.com/sirupsen/logrus"
|
|
"github.com/vulcand/oxy/utils"
|
|
)
|
|
|
|
// Compile time validation that the response recorder implements http interfaces correctly.
|
|
var _ middlewares.Stateful = &responseRecorderWithCloseNotify{}
|
|
|
|
const (
|
|
typeName = "customError"
|
|
backendURL = "http://0.0.0.0"
|
|
)
|
|
|
|
type serviceBuilder interface {
|
|
BuildHTTP(ctx context.Context, serviceName string, responseModifier func(*http.Response) error) (http.Handler, error)
|
|
}
|
|
|
|
// customErrors is a middleware that provides the custom error pages..
|
|
type customErrors struct {
|
|
name string
|
|
next http.Handler
|
|
backendHandler http.Handler
|
|
httpCodeRanges types.HTTPCodeRanges
|
|
backendQuery string
|
|
}
|
|
|
|
// New creates a new custom error pages middleware.
|
|
func New(ctx context.Context, next http.Handler, config config.ErrorPage, serviceBuilder serviceBuilder, name string) (http.Handler, error) {
|
|
middlewares.GetLogger(ctx, name, typeName).Debug("Creating middleware")
|
|
|
|
httpCodeRanges, err := types.NewHTTPCodeRanges(config.Status)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
backend, err := serviceBuilder.BuildHTTP(ctx, config.Service, nil)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &customErrors{
|
|
name: name,
|
|
next: next,
|
|
backendHandler: backend,
|
|
httpCodeRanges: httpCodeRanges,
|
|
backendQuery: config.Query,
|
|
}, nil
|
|
}
|
|
|
|
func (c *customErrors) GetTracingInformation() (string, ext.SpanKindEnum) {
|
|
return c.name, tracing.SpanKindNoneEnum
|
|
}
|
|
|
|
func (c *customErrors) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
|
|
logger := middlewares.GetLogger(req.Context(), c.name, typeName)
|
|
|
|
if c.backendHandler == nil {
|
|
logger.Error("Error pages: no backend handler.")
|
|
tracing.SetErrorWithEvent(req, "Error pages: no backend handler.")
|
|
c.next.ServeHTTP(rw, req)
|
|
return
|
|
}
|
|
|
|
recorder := newResponseRecorder(rw, middlewares.GetLogger(context.Background(), "test", typeName))
|
|
c.next.ServeHTTP(recorder, req)
|
|
|
|
// check the recorder code against the configured http status code ranges
|
|
for _, block := range c.httpCodeRanges {
|
|
if recorder.GetCode() >= block[0] && recorder.GetCode() <= block[1] {
|
|
logger.Errorf("Caught HTTP Status Code %d, returning error page", recorder.GetCode())
|
|
|
|
var query string
|
|
if len(c.backendQuery) > 0 {
|
|
query = "/" + strings.TrimPrefix(c.backendQuery, "/")
|
|
query = strings.Replace(query, "{status}", strconv.Itoa(recorder.GetCode()), -1)
|
|
}
|
|
|
|
pageReq, err := newRequest(backendURL + query)
|
|
if err != nil {
|
|
logger.Error(err)
|
|
rw.WriteHeader(recorder.GetCode())
|
|
_, err = fmt.Fprint(rw, http.StatusText(recorder.GetCode()))
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
return
|
|
}
|
|
|
|
recorderErrorPage := newResponseRecorder(rw, middlewares.GetLogger(context.Background(), "test", typeName))
|
|
utils.CopyHeaders(pageReq.Header, req.Header)
|
|
|
|
c.backendHandler.ServeHTTP(recorderErrorPage, pageReq.WithContext(req.Context()))
|
|
|
|
utils.CopyHeaders(rw.Header(), recorderErrorPage.Header())
|
|
rw.WriteHeader(recorder.GetCode())
|
|
|
|
if _, err = rw.Write(recorderErrorPage.GetBody().Bytes()); err != nil {
|
|
logger.Error(err)
|
|
}
|
|
return
|
|
}
|
|
}
|
|
|
|
// did not catch a configured status code so proceed with the request
|
|
utils.CopyHeaders(rw.Header(), recorder.Header())
|
|
rw.WriteHeader(recorder.GetCode())
|
|
_, err := rw.Write(recorder.GetBody().Bytes())
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
}
|
|
|
|
func newRequest(baseURL string) (*http.Request, error) {
|
|
u, err := url.Parse(baseURL)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("error pages: error when parse URL: %v", err)
|
|
}
|
|
|
|
req, err := http.NewRequest(http.MethodGet, u.String(), nil)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("error pages: error when create query: %v", err)
|
|
}
|
|
|
|
req.RequestURI = u.RequestURI()
|
|
return req, nil
|
|
}
|
|
|
|
type responseRecorder interface {
|
|
http.ResponseWriter
|
|
http.Flusher
|
|
GetCode() int
|
|
GetBody() *bytes.Buffer
|
|
IsStreamingResponseStarted() bool
|
|
}
|
|
|
|
// newResponseRecorder returns an initialized responseRecorder.
|
|
func newResponseRecorder(rw http.ResponseWriter, logger logrus.FieldLogger) responseRecorder {
|
|
recorder := &responseRecorderWithoutCloseNotify{
|
|
HeaderMap: make(http.Header),
|
|
Body: new(bytes.Buffer),
|
|
Code: http.StatusOK,
|
|
responseWriter: rw,
|
|
logger: logger,
|
|
}
|
|
if _, ok := rw.(http.CloseNotifier); ok {
|
|
return &responseRecorderWithCloseNotify{recorder}
|
|
}
|
|
return recorder
|
|
}
|
|
|
|
// responseRecorderWithoutCloseNotify is an implementation of http.ResponseWriter that
|
|
// records its mutations for later inspection.
|
|
type responseRecorderWithoutCloseNotify struct {
|
|
Code int // the HTTP response code from WriteHeader
|
|
HeaderMap http.Header // the HTTP response headers
|
|
Body *bytes.Buffer // if non-nil, the bytes.Buffer to append written data to
|
|
|
|
responseWriter http.ResponseWriter
|
|
err error
|
|
streamingResponseStarted bool
|
|
logger logrus.FieldLogger
|
|
}
|
|
|
|
type responseRecorderWithCloseNotify struct {
|
|
*responseRecorderWithoutCloseNotify
|
|
}
|
|
|
|
// CloseNotify returns a channel that receives at most a
|
|
// single value (true) when the client connection has gone away.
|
|
func (r *responseRecorderWithCloseNotify) CloseNotify() <-chan bool {
|
|
return r.responseWriter.(http.CloseNotifier).CloseNotify()
|
|
}
|
|
|
|
// Header returns the response headers.
|
|
func (r *responseRecorderWithoutCloseNotify) Header() http.Header {
|
|
if r.HeaderMap == nil {
|
|
r.HeaderMap = make(http.Header)
|
|
}
|
|
|
|
return r.HeaderMap
|
|
}
|
|
|
|
func (r *responseRecorderWithoutCloseNotify) GetCode() int {
|
|
return r.Code
|
|
}
|
|
|
|
func (r *responseRecorderWithoutCloseNotify) GetBody() *bytes.Buffer {
|
|
return r.Body
|
|
}
|
|
|
|
func (r *responseRecorderWithoutCloseNotify) IsStreamingResponseStarted() bool {
|
|
return r.streamingResponseStarted
|
|
}
|
|
|
|
// Write always succeeds and writes to rw.Body, if not nil.
|
|
func (r *responseRecorderWithoutCloseNotify) Write(buf []byte) (int, error) {
|
|
if r.err != nil {
|
|
return 0, r.err
|
|
}
|
|
return r.Body.Write(buf)
|
|
}
|
|
|
|
// WriteHeader sets rw.Code.
|
|
func (r *responseRecorderWithoutCloseNotify) WriteHeader(code int) {
|
|
r.Code = code
|
|
}
|
|
|
|
// Hijack hijacks the connection
|
|
func (r *responseRecorderWithoutCloseNotify) Hijack() (net.Conn, *bufio.ReadWriter, error) {
|
|
return r.responseWriter.(http.Hijacker).Hijack()
|
|
}
|
|
|
|
// Flush sends any buffered data to the client.
|
|
func (r *responseRecorderWithoutCloseNotify) Flush() {
|
|
if !r.streamingResponseStarted {
|
|
utils.CopyHeaders(r.responseWriter.Header(), r.Header())
|
|
r.responseWriter.WriteHeader(r.Code)
|
|
r.streamingResponseStarted = true
|
|
}
|
|
|
|
_, err := r.responseWriter.Write(r.Body.Bytes())
|
|
if err != nil {
|
|
r.logger.Errorf("Error writing response in responseRecorder: %v", err)
|
|
r.err = err
|
|
}
|
|
r.Body.Reset()
|
|
|
|
if flusher, ok := r.responseWriter.(http.Flusher); ok {
|
|
flusher.Flush()
|
|
}
|
|
}
|