35 lines
880 B
Go
35 lines
880 B
Go
package server
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import (
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"net/http"
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"net/url"
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"path"
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"strings"
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)
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type interceptingResponseWriter struct {
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http.ResponseWriter
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Prefix string
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}
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func (i *interceptingResponseWriter) WriteHeader(status int) {
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if status >= 300 && status < 400 {
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location := i.ResponseWriter.Header().Get("Location")
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if u, err := url.Parse(location); err == nil && !u.IsAbs() {
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if !strings.HasPrefix(location, i.Prefix) {
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i.ResponseWriter.Header().Set("Location", path.Join(i.Prefix, location)+"/")
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}
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}
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}
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i.ResponseWriter.WriteHeader(status)
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}
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// PrefixingRedirector alters the Location header of downstream http.Handlers
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// to include a specified prefix
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func PrefixedRedirect(prefix string, next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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iw := &interceptingResponseWriter{w, prefix}
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next.ServeHTTP(iw, r)
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})
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}
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