mirror of
https://github.com/caddyserver/caddy.git
synced 2024-11-26 02:09:47 +08:00
111 lines
2.8 KiB
Go
111 lines
2.8 KiB
Go
// Package header provides middleware that appends headers to
|
|
// requests based on a set of configuration rules that define
|
|
// which routes receive which headers.
|
|
package header
|
|
|
|
import (
|
|
"net/http"
|
|
"strings"
|
|
|
|
"github.com/mholt/caddy/caddyhttp/httpserver"
|
|
)
|
|
|
|
// Headers is middleware that adds headers to the responses
|
|
// for requests matching a certain path.
|
|
type Headers struct {
|
|
Next httpserver.Handler
|
|
Rules []Rule
|
|
}
|
|
|
|
// ServeHTTP implements the httpserver.Handler interface and serves requests,
|
|
// setting headers on the response according to the configured rules.
|
|
func (h Headers) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
|
|
replacer := httpserver.NewReplacer(r, nil, "")
|
|
rww := &responseWriterWrapper{
|
|
ResponseWriterWrapper: &httpserver.ResponseWriterWrapper{ResponseWriter: w},
|
|
}
|
|
for _, rule := range h.Rules {
|
|
if httpserver.Path(r.URL.Path).Matches(rule.Path) {
|
|
for name := range rule.Headers {
|
|
|
|
// One can either delete a header, add multiple values to a header, or simply
|
|
// set a header.
|
|
|
|
if strings.HasPrefix(name, "-") {
|
|
rww.delHeader(strings.TrimLeft(name, "-"))
|
|
} else if strings.HasPrefix(name, "+") {
|
|
for _, value := range rule.Headers[name] {
|
|
rww.Header().Add(strings.TrimLeft(name, "+"), replacer.Replace(value))
|
|
}
|
|
} else {
|
|
for _, value := range rule.Headers[name] {
|
|
rww.Header().Set(name, replacer.Replace(value))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return h.Next.ServeHTTP(rww, r)
|
|
}
|
|
|
|
type (
|
|
// Rule groups a slice of HTTP headers by a URL pattern.
|
|
Rule struct {
|
|
Path string
|
|
Headers http.Header
|
|
}
|
|
)
|
|
|
|
// headerOperation represents an operation on the header
|
|
type headerOperation func(http.Header)
|
|
|
|
// responseWriterWrapper wraps the real ResponseWriter.
|
|
// It defers header operations until writeHeader
|
|
type responseWriterWrapper struct {
|
|
*httpserver.ResponseWriterWrapper
|
|
ops []headerOperation
|
|
wroteHeader bool
|
|
}
|
|
|
|
func (rww *responseWriterWrapper) Header() http.Header {
|
|
return rww.ResponseWriterWrapper.Header()
|
|
}
|
|
|
|
func (rww *responseWriterWrapper) Write(d []byte) (int, error) {
|
|
if !rww.wroteHeader {
|
|
rww.WriteHeader(http.StatusOK)
|
|
}
|
|
return rww.ResponseWriterWrapper.Write(d)
|
|
}
|
|
|
|
func (rww *responseWriterWrapper) WriteHeader(status int) {
|
|
if rww.wroteHeader {
|
|
return
|
|
}
|
|
rww.wroteHeader = true
|
|
// capture the original headers
|
|
h := rww.Header()
|
|
|
|
// perform our revisions
|
|
for _, op := range rww.ops {
|
|
op(h)
|
|
}
|
|
|
|
rww.ResponseWriterWrapper.WriteHeader(status)
|
|
}
|
|
|
|
// delHeader deletes the existing header according to the key
|
|
// Also it will delete that header added later.
|
|
func (rww *responseWriterWrapper) delHeader(key string) {
|
|
// remove the existing one if any
|
|
rww.Header().Del(key)
|
|
|
|
// register a future deletion
|
|
rww.ops = append(rww.ops, func(h http.Header) {
|
|
h.Del(key)
|
|
})
|
|
}
|
|
|
|
// Interface guards
|
|
var _ httpserver.HTTPInterfaces = (*responseWriterWrapper)(nil)
|