cache/httpcache: Add respectCacheControlNoStoreInResponse and respectCacheControlNoStoreInRequest options

This cache is used by `resources.GetRemote`.

Default values are:

* respectCacheControlNoStoreInResponse: false
* respectCacheControlNoStoreInRequest: true

This is a slightly breaking change, but the current behaviour is confusing, as:

* Many servers set the `no-store` header without much consideration, see https://developer.chrome.com/docs/web-platform/bfcache-ccns for more context
* We almost always want to cache the `resources.GetRemote` to disk.

Fixes #13990

Author: bep

cache/httpcache/httpcache.go

@@ -25,6 +25,8 @@ import (
 
 // DefaultConfig holds the default configuration for the HTTP cache.
 var DefaultConfig = Config{
+	RespectCacheControlNoStoreInRequest:  true,
+	RespectCacheControlNoStoreInResponse: false,
 	Cache: Cache{
 		For: GlobMatcher{
 			Excludes: []string{"**"},
@@ -42,7 +44,13 @@ var DefaultConfig = Config{
 
 // Config holds the configuration for the HTTP cache.
 type Config struct {
-	// Configures the HTTP cache behavior (RFC 9111).
+	// When enabled and there's a Cache-Control: no-store directive in the request, response will never be stored in disk cache.
+	RespectCacheControlNoStoreInRequest bool
+
+	// When enabled and there's a Cache-Control: no-store directive in the response, response will never be stored in disk cache.
+	RespectCacheControlNoStoreInResponse bool
+
+	// Enables HTTP cache behavior (RFC 9111) for these resources.
 	// When this is not enabled for a resource, Hugo will go straight to the file cache.
 	Cache Cache
 
@@ -57,7 +65,9 @@ type Cache struct {
 }
 
 func (c *Config) Compile() (ConfigCompiled, error) {
-	var cc ConfigCompiled
+	cc := ConfigCompiled{
+		Base: *c,
+	}
 
 	p, err := c.Cache.For.CompilePredicate()
 	if err != nil {
@@ -127,6 +137,7 @@ func (gm GlobMatcher) IsZero() bool {
 }
 
 type ConfigCompiled struct {
+	Base        Config
 	For         predicate.P[string]
 	PollConfigs []PollConfigCompiled
 }

go.mod

@@ -37,7 +37,7 @@ require (
 	github.com/gobwas/glob v0.2.3
 	github.com/gohugoio/go-i18n/v2 v2.1.3-0.20230805085216-e63c13218d0e
 	github.com/gohugoio/hashstructure v0.5.0
-	github.com/gohugoio/httpcache v0.7.0
+	github.com/gohugoio/httpcache v0.8.0
 	github.com/gohugoio/hugo-goldmark-extensions/extras v0.5.0
 	github.com/gohugoio/hugo-goldmark-extensions/passthrough v0.3.1
 	github.com/gohugoio/locales v0.14.0

go.sum

@@ -268,6 +268,8 @@ github.com/gohugoio/hashstructure v0.5.0 h1:G2fjSBU36RdwEJBWJ+919ERvOVqAg9tfcYp4
 github.com/gohugoio/hashstructure v0.5.0/go.mod h1:Ser0TniXuu/eauYmrwM4o64EBvySxNzITEOLlm4igec=
 github.com/gohugoio/httpcache v0.7.0 h1:ukPnn04Rgvx48JIinZvZetBfHaWE7I01JR2Q2RrQ3Vs=
 github.com/gohugoio/httpcache v0.7.0/go.mod h1:fMlPrdY/vVJhAriLZnrF5QpN3BNAcoBClgAyQd+lGFI=
+github.com/gohugoio/httpcache v0.8.0 h1:hNdsmGSELztetYCsPVgjA960zSa4dfEqqF/SficorCU=
+github.com/gohugoio/httpcache v0.8.0/go.mod h1:fMlPrdY/vVJhAriLZnrF5QpN3BNAcoBClgAyQd+lGFI=
 github.com/gohugoio/hugo-goldmark-extensions/extras v0.5.0 h1:dco+7YiOryRoPOMXwwaf+kktZSCtlFtreNdiJbETvYE=
 github.com/gohugoio/hugo-goldmark-extensions/extras v0.5.0/go.mod h1:CRrxQTKeM3imw+UoS4EHKyrqB7Zp6sAJiqHit+aMGTE=
 github.com/gohugoio/hugo-goldmark-extensions/passthrough v0.3.1 h1:nUzXfRTszLliZuN0JTKeunXTRaiFX6ksaWP0puLLYAY=

resources/resource_factories/create/create.go

@@ -111,6 +111,19 @@ func New(rs *resources.Spec) *Client {
 				ShouldCache: func(req *http.Request, resp *http.Response, key string) bool {
 					return shouldCache(resp.StatusCode)
 				},
+				CanStore: func(reqCacheControl, respCacheControl httpcache.CacheControl) (canStore bool) {
+					if httpCacheConfig.Base.RespectCacheControlNoStoreInResponse {
+						if _, ok := respCacheControl["no-store"]; ok {
+							return false
+						}
+					}
+					if httpCacheConfig.Base.RespectCacheControlNoStoreInRequest {
+						if _, ok := reqCacheControl["no-store"]; ok {
+							return false
+						}
+					}
+					return true
+				},
 				MarkCachedResponses: true,
 				EnableETagPair:      true,
 				Transport: &transport{