Set cache headers for layers.

- Set an Etag header
     - Check If-None-Match and respond appropriately
     - Set a Cache-Control header with a default of 1 week

Signed-off-by: Richard Scothern <richard.scothern@gmail.com>
This commit is contained in:
Richard 2015-05-12 17:49:18 -07:00
parent fbd022e452
commit 3dc2d849c7
2 changed files with 62 additions and 0 deletions

View file

@ -263,6 +263,43 @@ func TestLayerAPI(t *testing.T) {
checkResponse(t, "fetching layer bad digest", resp, http.StatusBadRequest)
// Cache headers
resp, err = http.Get(layerURL)
if err != nil {
t.Fatalf("unexpected error fetching layer: %v", err)
}
checkResponse(t, "fetching layer", resp, http.StatusOK)
checkHeaders(t, resp, http.Header{
"Content-Length": []string{fmt.Sprint(layerLength)},
"Docker-Content-Digest": []string{layerDigest.String()},
"ETag": []string{layerDigest.String()},
"Cache-Control": []string{"max-age=86400"},
})
// Matching etag, gives 304
etag := resp.Header.Get("Etag")
req, err = http.NewRequest("GET", layerURL, nil)
if err != nil {
t.Fatalf("Error constructing request: %s", err)
}
req.Header.Set("If-None-Match", etag)
resp, err = http.DefaultClient.Do(req)
if err != nil {
t.Fatalf("Error constructing request: %s", err)
}
checkResponse(t, "fetching layer with etag", resp, http.StatusNotModified)
// Non-matching etag, gives 200
req, err = http.NewRequest("GET", layerURL, nil)
if err != nil {
t.Fatalf("Error constructing request: %s", err)
}
req.Header.Set("If-None-Match", "")
resp, err = http.DefaultClient.Do(req)
checkResponse(t, "fetching layer with invalid etag", resp, http.StatusOK)
// Missing tests:
// - Upload the same tarsum file under and different repository and
// ensure the content remains uncorrupted.

View file

@ -1,6 +1,7 @@
package storage
import (
"fmt"
"net/http"
"time"
@ -73,7 +74,31 @@ func (lr *layerReader) Handler(r *http.Request) (h http.Handler, err error) {
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// If the registry is serving this content itself, check
// the If-None-Match header and return 304 on match. Redirected
// storage implementations do the same.
if etagMatch(r, lr.digest.String()) {
w.WriteHeader(http.StatusNotModified)
return
}
setCacheHeaders(w, 86400, lr.digest.String())
w.Header().Set("Docker-Content-Digest", lr.digest.String())
handlerFunc.ServeHTTP(w, r)
}), nil
}
func etagMatch(r *http.Request, etag string) bool {
for _, headerVal := range r.Header["If-None-Match"] {
if headerVal == etag {
return true
}
}
return false
}
func setCacheHeaders(w http.ResponseWriter, cacheAge int, etag string) {
w.Header().Set("ETag", etag)
w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%d", cacheAge))
}