drone/app/api/middleware/nocache/nocache.go
2024-05-03 20:03:37 +00:00

49 lines
1.4 KiB
Go

// Copyright 2023 Harness, Inc.
//
// 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 nocache
import (
"net/http"
"time"
)
// Ported from Chi's middleware, source:
// https://github.com/go-chi/chi/blob/v5.0.12/middleware/nocache.go
// Modified the middleware to retain ETags.
var epoch = time.Unix(0, 0).Format(time.RFC1123)
var noCacheHeaders = map[string]string{
"Expires": epoch,
"Cache-Control": "no-cache, no-store, no-transform, must-revalidate, private, max-age=0",
"Pragma": "no-cache",
"X-Accel-Expires": "0",
}
// NoCache is same as chi's default NoCache middleware except it doesn't remove etag headers.
func NoCache(h http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
// Set our NoCache headers
for k, v := range noCacheHeaders {
w.Header().Set(k, v)
}
h.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}