148 lines
3.4 KiB
Go
148 lines
3.4 KiB
Go
package redirect
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"html/template"
|
|
"io"
|
|
"net/http"
|
|
"net/url"
|
|
"regexp"
|
|
"strings"
|
|
|
|
"github.com/containous/traefik/config"
|
|
"github.com/containous/traefik/middlewares"
|
|
"github.com/containous/traefik/tracing"
|
|
"github.com/opentracing/opentracing-go/ext"
|
|
"github.com/vulcand/oxy/utils"
|
|
)
|
|
|
|
const (
|
|
typeName = "Redirect"
|
|
)
|
|
|
|
type redirect struct {
|
|
next http.Handler
|
|
regex *regexp.Regexp
|
|
replacement string
|
|
permanent bool
|
|
errHandler utils.ErrorHandler
|
|
name string
|
|
}
|
|
|
|
// New creates a redirect middleware.
|
|
func New(ctx context.Context, next http.Handler, config config.Redirect, name string) (http.Handler, error) {
|
|
logger := middlewares.GetLogger(ctx, name, typeName)
|
|
logger.Debug("Creating middleware")
|
|
logger.Debugf("Setting up redirect %s -> %s", config.Regex, config.Replacement)
|
|
|
|
re, err := regexp.Compile(config.Regex)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &redirect{
|
|
regex: re,
|
|
replacement: config.Replacement,
|
|
permanent: config.Permanent,
|
|
errHandler: utils.DefaultHandler,
|
|
next: next,
|
|
name: name,
|
|
}, nil
|
|
}
|
|
|
|
func (r *redirect) GetTracingInformation() (string, ext.SpanKindEnum) {
|
|
return r.name, tracing.SpanKindNoneEnum
|
|
}
|
|
|
|
func (r *redirect) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
|
|
oldURL := rawURL(req)
|
|
|
|
// If the Regexp doesn't match, skip to the next handler
|
|
if !r.regex.MatchString(oldURL) {
|
|
r.next.ServeHTTP(rw, req)
|
|
return
|
|
}
|
|
|
|
// apply a rewrite regexp to the URL
|
|
newURL := r.regex.ReplaceAllString(oldURL, r.replacement)
|
|
|
|
// replace any variables that may be in there
|
|
rewrittenURL := &bytes.Buffer{}
|
|
if err := applyString(newURL, rewrittenURL, req); err != nil {
|
|
r.errHandler.ServeHTTP(rw, req, err)
|
|
return
|
|
}
|
|
|
|
// parse the rewritten URL and replace request URL with it
|
|
parsedURL, err := url.Parse(rewrittenURL.String())
|
|
if err != nil {
|
|
r.errHandler.ServeHTTP(rw, req, err)
|
|
return
|
|
}
|
|
|
|
if newURL != oldURL {
|
|
handler := &moveHandler{location: parsedURL, permanent: r.permanent}
|
|
handler.ServeHTTP(rw, req)
|
|
return
|
|
}
|
|
|
|
req.URL = parsedURL
|
|
|
|
// make sure the request URI corresponds the rewritten URL
|
|
req.RequestURI = req.URL.RequestURI()
|
|
r.next.ServeHTTP(rw, req)
|
|
}
|
|
|
|
type moveHandler struct {
|
|
location *url.URL
|
|
permanent bool
|
|
}
|
|
|
|
func (m *moveHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
|
|
rw.Header().Set("Location", m.location.String())
|
|
|
|
status := http.StatusFound
|
|
if req.Method != http.MethodGet {
|
|
status = http.StatusTemporaryRedirect
|
|
}
|
|
|
|
if m.permanent {
|
|
status = http.StatusMovedPermanently
|
|
if req.Method != http.MethodGet {
|
|
status = http.StatusPermanentRedirect
|
|
}
|
|
}
|
|
rw.WriteHeader(status)
|
|
_, err := rw.Write([]byte(http.StatusText(status)))
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
}
|
|
|
|
func rawURL(req *http.Request) string {
|
|
scheme := "http"
|
|
if req.TLS != nil || isXForwardedHTTPS(req) {
|
|
scheme = "https"
|
|
}
|
|
|
|
return strings.Join([]string{scheme, "://", req.Host, req.RequestURI}, "")
|
|
}
|
|
|
|
func isXForwardedHTTPS(request *http.Request) bool {
|
|
xForwardedProto := request.Header.Get("X-Forwarded-Proto")
|
|
|
|
return len(xForwardedProto) > 0 && xForwardedProto == "https"
|
|
}
|
|
|
|
func applyString(in string, out io.Writer, req *http.Request) error {
|
|
t, err := template.New("t").Parse(in)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
data := struct{ Request *http.Request }{Request: req}
|
|
|
|
return t.Execute(out, data)
|
|
}
|