feat(cve): cache trivy results for an image:tag (#1101)

Signed-off-by: Andrei Aaron <aaaron@luxoft.com>

pkg/extensions/search/cve/trivy/cache.go

@@ -0,0 +1,41 @@
+package trivy
+
+import (
+	lru "github.com/hashicorp/golang-lru"
+
+	cvemodel "zotregistry.io/zot/pkg/extensions/search/cve/model"
+	"zotregistry.io/zot/pkg/log"
+)
+
+type CveCache struct {
+	cache *lru.Cache
+	log   log.Logger
+}
+
+func NewCveCache(size int, log log.Logger) *CveCache {
+	cache, _ := lru.New(size)
+
+	return &CveCache{cache: cache, log: log}
+}
+
+func (cveCache *CveCache) Add(image string, cveMap map[string]cvemodel.CVE) {
+	cveCache.cache.Add(image, cveMap)
+}
+
+func (cveCache *CveCache) Get(image string) map[string]cvemodel.CVE {
+	value, ok := cveCache.cache.Get(image)
+	if !ok {
+		return nil
+	}
+
+	cveMap, ok := value.(map[string]cvemodel.CVE)
+	if !ok {
+		return nil
+	}
+
+	return cveMap
+}
+
+func (cveCache *CveCache) Purge() {
+	cveCache.cache.Purge()
+}

pkg/extensions/search/cve/trivy/scanner.go

@@ -77,6 +77,7 @@ type Scanner struct {
 	storeController storage.StoreController
 	log             log.Logger
 	dbLock          *sync.Mutex
+	cache           *CveCache
 }
 
 func NewScanner(storeController storage.StoreController,
@@ -114,6 +115,7 @@ func NewScanner(storeController storage.StoreController,
 		cveController:   cveController,
 		storeController: storeController,
 		dbLock:          &sync.Mutex{},
+		cache:           NewCveCache(10000, log), //nolint:gomnd
 	}
 }
 
@@ -147,6 +149,10 @@ func (scanner Scanner) getTrivyContext(image string) *trivyCtx {
 }
 
 func (scanner Scanner) IsImageFormatScannable(image string) (bool, error) {
+	if scanner.cache.Get(image) != nil {
+		return true, nil
+	}
+
 	imageDir, inputTag := common.GetImageDirAndTag(image)
 
 	repoMeta, err := scanner.repoDB.GetRepoMeta(imageDir)
@@ -194,6 +200,10 @@ func (scanner Scanner) IsImageFormatScannable(image string) (bool, error) {
 }
 
 func (scanner Scanner) ScanImage(image string) (map[string]cvemodel.CVE, error) {
+	if scanner.cache.Get(image) != nil {
+		return scanner.cache.Get(image), nil
+	}
+
 	cveidMap := make(map[string]cvemodel.CVE)
 
 	scanner.log.Debug().Str("image", image).Msg("scanning image")
@@ -264,6 +274,8 @@ func (scanner Scanner) ScanImage(image string) (map[string]cvemodel.CVE, error)
 		}
 	}
 
+	scanner.cache.Add(image, cveidMap)
+
 	return cveidMap, nil
 }
 
@@ -293,6 +305,8 @@ func (scanner Scanner) UpdateDB() error {
 		}
 	}
 
+	scanner.cache.Purge()
+
 	return nil
 }