caddy/modules/caddyhttp/staticresp.go
Matt Holt e2c5c28597
caddyhttp: Implement handler abort; new 'abort' directive (close #3871) (#3983)
* caddyhttp: Implement handler abort; new 'abort' directive (close #3871)

* Move abort directive ordering; clean up redirects

Seems logical for the end-all of handlers to go at the... end.

The Connection header no longer needs to be set there, since Close is
true, and the static_response handler now does that.
2021-01-28 12:54:55 -07:00

171 lines
4.4 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddyhttp
import (
"fmt"
"net/http"
"strconv"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
)
func init() {
caddy.RegisterModule(StaticResponse{})
}
// StaticResponse implements a simple responder for static responses.
type StaticResponse struct {
// The HTTP status code to respond with. Can be an integer or,
// if needing to use a placeholder, a string.
StatusCode WeakString `json:"status_code,omitempty"`
// Header fields to set on the response.
Headers http.Header `json:"headers,omitempty"`
// The response body.
Body string `json:"body,omitempty"`
// If true, the server will close the client's connection
// after writing the response.
Close bool `json:"close,omitempty"`
// Immediately and forcefully closes the connection without
// writing a response. Interrupts any other HTTP streams on
// the same connection.
Abort bool `json:"abort,omitempty"`
}
// CaddyModule returns the Caddy module information.
func (StaticResponse) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "http.handlers.static_response",
New: func() caddy.Module { return new(StaticResponse) },
}
}
// UnmarshalCaddyfile sets up the handler from Caddyfile tokens. Syntax:
//
// respond [<matcher>] <status>|<body> [<status>] {
// body <text>
// close
// }
//
// If there is just one argument (other than the matcher), it is considered
// to be a status code if it's a valid positive integer of 3 digits.
func (s *StaticResponse) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
for d.Next() {
args := d.RemainingArgs()
switch len(args) {
case 1:
if len(args[0]) == 3 {
if num, err := strconv.Atoi(args[0]); err == nil && num > 0 {
s.StatusCode = WeakString(args[0])
break
}
}
s.Body = args[0]
case 2:
s.Body = args[0]
s.StatusCode = WeakString(args[1])
default:
return d.ArgErr()
}
for d.NextBlock(0) {
switch d.Val() {
case "body":
if s.Body != "" {
return d.Err("body already specified")
}
if !d.AllArgs(&s.Body) {
return d.ArgErr()
}
case "close":
if s.Close {
return d.Err("close already specified")
}
s.Close = true
}
}
}
return nil
}
func (s StaticResponse) ServeHTTP(w http.ResponseWriter, r *http.Request, _ Handler) error {
// close the connection immediately
if s.Abort {
panic(http.ErrAbortHandler)
}
// close the connection after responding
if s.Close {
r.Close = true
w.Header().Set("Connection", "close")
}
repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
// set all headers
for field, vals := range s.Headers {
field = repl.ReplaceAll(field, "")
newVals := make([]string, len(vals))
for i := range vals {
newVals[i] = repl.ReplaceAll(vals[i], "")
}
w.Header()[field] = newVals
}
// do not allow Go to sniff the content-type
if w.Header().Get("Content-Type") == "" {
w.Header()["Content-Type"] = nil
}
// get the status code; if this handler exists in an error route,
// use the recommended status code as the default; otherwise 200
statusCode := http.StatusOK
if reqErr, ok := r.Context().Value(ErrorCtxKey).(error); ok {
if handlerErr, ok := reqErr.(HandlerError); ok {
if handlerErr.StatusCode > 0 {
statusCode = handlerErr.StatusCode
}
}
}
if codeStr := s.StatusCode.String(); codeStr != "" {
intVal, err := strconv.Atoi(repl.ReplaceAll(codeStr, ""))
if err != nil {
return Error(http.StatusInternalServerError, err)
}
statusCode = intVal
}
// write headers
w.WriteHeader(statusCode)
// write response body
if s.Body != "" {
fmt.Fprint(w, repl.ReplaceKnown(s.Body, ""))
}
return nil
}
// Interface guards
var (
_ MiddlewareHandler = (*StaticResponse)(nil)
_ caddyfile.Unmarshaler = (*StaticResponse)(nil)
)