61 lines
1.7 KiB
Go
61 lines
1.7 KiB
Go
package middlewares
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import (
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"context"
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"net/http"
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"strings"
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)
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const (
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// StripPrefixKey is the key within the request context used to
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// store the stripped prefix
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StripPrefixKey key = "StripPrefix"
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// StripPrefixSlashKey is the key within the request context used to
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// store the stripped slash
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StripPrefixSlashKey key = "StripPrefixSlash"
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// ForwardedPrefixHeader is the default header to set prefix
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ForwardedPrefixHeader = "X-Forwarded-Prefix"
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)
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// StripPrefix is a middleware used to strip prefix from an URL request
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type StripPrefix struct {
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Handler http.Handler
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Prefixes []string
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}
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func (s *StripPrefix) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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for _, prefix := range s.Prefixes {
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if strings.HasPrefix(r.URL.Path, prefix) {
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trailingSlash := r.URL.Path == prefix+"/"
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r.URL.Path = stripPrefix(r.URL.Path, prefix)
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if r.URL.RawPath != "" {
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r.URL.RawPath = stripPrefix(r.URL.RawPath, prefix)
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}
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s.serveRequest(w, r, strings.TrimSpace(prefix), trailingSlash)
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return
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}
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}
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http.NotFound(w, r)
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}
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func (s *StripPrefix) serveRequest(w http.ResponseWriter, r *http.Request, prefix string, trailingSlash bool) {
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r = r.WithContext(context.WithValue(r.Context(), StripPrefixSlashKey, trailingSlash))
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r = r.WithContext(context.WithValue(r.Context(), StripPrefixKey, prefix))
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r.Header.Add(ForwardedPrefixHeader, prefix)
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r.RequestURI = r.URL.RequestURI()
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s.Handler.ServeHTTP(w, r)
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}
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// SetHandler sets handler
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func (s *StripPrefix) SetHandler(Handler http.Handler) {
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s.Handler = Handler
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}
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func stripPrefix(s, prefix string) string {
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return ensureLeadingSlash(strings.TrimPrefix(s, prefix))
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}
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func ensureLeadingSlash(str string) string {
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return "/" + strings.TrimPrefix(str, "/")
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}
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