// Package redirect is middleware for redirecting certain requests
// to other locations.
package redirect
import (
"fmt"
"html"
"net/http"
"github.com/mholt/caddy/caddyhttp/httpserver"
)
// Redirect is middleware to respond with HTTP redirects
type Redirect struct {
Next httpserver.Handler
Rules []Rule
}
// ServeHTTP implements the httpserver.Handler interface.
func (rd Redirect) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
for _, rule := range rd.Rules {
if (rule.FromPath == "/" || r.URL.Path == rule.FromPath) && schemeMatches(rule, r) {
to := httpserver.NewReplacer(r, nil, "").Replace(rule.To)
if rule.Meta {
safeTo := html.EscapeString(to)
fmt.Fprintf(w, metaRedir, safeTo, safeTo)
} else {
http.Redirect(w, r, to, rule.Code)
}
return 0, nil
}
}
return rd.Next.ServeHTTP(w, r)
}
func schemeMatches(rule Rule, req *http.Request) bool {
return (rule.FromScheme == "https" && req.TLS != nil) ||
(rule.FromScheme != "https" && req.TLS == nil)
}
// Rule describes an HTTP redirect rule.
type Rule struct {
FromScheme, FromPath, To string
Code int
Meta bool
}
// Script tag comes first since that will better imitate a redirect in the browser's
// history, but the meta tag is a fallback for most non-JS clients.
const metaRedir = `
Redirecting...
`