Support force cache even when server doesn't set the Date header

This fixes a bug where when a upstream server doesn't set a Date header the response will be cached but then once the cache is expired it never gets refreshed because parseResponseHeaders returns a no date header error This also makes it so that the force_cache_duration_seconds is respected when an upstream returns a 304 not modified Signed-off-by: Peter <[email protected]>
open-policy-agent · Aug 22, 2023 · 218979d · 218979d
1 parent de896d9
commit 218979d
Showing 1 changed file with 14 additions and 5 deletions.
diff --git a/topdown/http.go b/topdown/http.go
@@ -841,7 +841,11 @@ func (c *interQueryCache) checkHTTPSendInterQueryCache() (ast.Value, error) {
 
 	headers, err := parseResponseHeaders(cachedRespData.Headers)
 	if err != nil {
-		return nil, err
+		if forceCaching(c.forceCacheParams) {
+			headers = &responseHeaders{}
+		} else {
+			return nil, err
+		}
 	}
 
 	// check with the server if the stale response is still up-to-date.
@@ -864,11 +868,16 @@ func (c *interQueryCache) checkHTTPSendInterQueryCache() (ast.Value, error) {
 			}
 		}
 
-		expiresAt, err := expiryFromHeaders(result.Header)
-		if err != nil {
-			return nil, err
+		if forceCaching(c.forceCacheParams) {
+			createdAt := getCurrentTime(c.bctx)
+			cachedRespData.ExpiresAt = createdAt.Add(time.Second * time.Duration(c.forceCacheParams.forceCacheDurationSeconds))
+		} else {
+			expiresAt, err := expiryFromHeaders(result.Header)
+			if err != nil {
+				return nil, err
+			}
+			cachedRespData.ExpiresAt = expiresAt
 		}
-		cachedRespData.ExpiresAt = expiresAt
 
 		cachingMode, err := getCachingMode(c.key)
 		if err != nil {