caddy/middleware/redirect/redirect.go
AJ ONeal d6a7dfc1a5 add ability to do meta redirects
Proper Location redirects are disadvantageous in some situations.
For example, you may want a developer to know that a resource is available
via https, but you don't want an insecure call to the API to succeed.
2015-06-10 05:48:40 +00:00

58 lines
1.3 KiB
Go

// Package redirect is middleware for redirecting certain requests
// to other locations.
package redirect
import (
"fmt"
"html"
"net/http"
"strings"
"github.com/mholt/caddy/middleware"
)
// Redirect is middleware to respond with HTTP redirects
type Redirect struct {
Next middleware.Handler
Rules []Rule
}
// ServeHTTP implements the middleware.Handler interface.
func (rd Redirect) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
for _, rule := range rd.Rules {
if rule.From == "/" {
// Catchall redirect preserves path (TODO: Standardize/formalize this behavior)
newPath := strings.TrimSuffix(rule.To, "/") + r.URL.Path
if rule.Meta {
fmt.Fprintf(w, metaRedir, html.EscapeString(newPath))
} else {
http.Redirect(w, r, newPath, rule.Code)
}
return 0, nil
}
if r.URL.Path == rule.From {
if rule.Meta {
fmt.Fprintf(w, metaRedir, html.EscapeString(rule.To))
} else {
http.Redirect(w, r, rule.To, rule.Code)
}
return 0, nil
}
}
return rd.Next.ServeHTTP(w, r)
}
// Rule describes an HTTP redirect rule.
type Rule struct {
From, To string
Code int
Meta bool
}
var metaRedir = `<html>
<head>
<meta http-equiv="refresh" content="0;URL='%s'">
</head>
<body>redirecting...</body>
</html>`