arrange power-user tasks ahead of parsing the source image

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

cmd/power_user.go

@@ -72,6 +72,12 @@ func powerUserExecWorker(userInput string) <-chan error {
 	go func() {
 		defer close(errs)
 
+		tasks, err := powerUserTasks()
+		if err != nil {
+			errs <- err
+			return
+		}
+
 		checkForApplicationUpdate()
 
 		src, cleanup, err := source.New(userInput)
@@ -90,14 +96,9 @@ func powerUserExecWorker(userInput string) <-chan error {
 			SourceMetadata:    src.Metadata,
 			ApplicationConfig: *appConfig,
 		}
-		tasks, err := powerUserTasks(src)
-		if err != nil {
-			errs <- err
-			return
-		}
 
 		for _, task := range tasks {
-			if err = task(&analysisResults); err != nil {
+			if err = task(&analysisResults, src); err != nil {
 				errs <- err
 				return
 			}

cmd/power_user_tasks.go

@@ -7,41 +7,36 @@ import (
 	"github.com/anchore/syft/syft/source"
 )
 
-type powerUserTask func(*poweruser.JSONDocumentConfig) error
+type powerUserTask func(*poweruser.JSONDocumentConfig, source.Source) error
 
-func powerUserTasks(src source.Source) ([]powerUserTask, error) {
+func powerUserTasks() ([]powerUserTask, error) {
 	var tasks []powerUserTask
-	var err error
-	var task powerUserTask
 
-	task = catalogPackagesTask(src)
+	generators := []func() (powerUserTask, error){
+		catalogPackagesTask,
+		catalogFileMetadataTask,
+		catalogFileDigestTask,
+	}
+
+	for _, generator := range generators {
+		task, err := generator()
+		if err != nil {
+			return nil, err
+		}
 		if task != nil {
 			tasks = append(tasks, task)
 		}
-
-	task, err = catalogFileMetadataTask(src)
-	if err != nil {
-		return nil, err
-	} else if task != nil {
-		tasks = append(tasks, task)
-	}
-
-	task, err = catalogFileDigestTask(src)
-	if err != nil {
-		return nil, err
-	} else if task != nil {
-		tasks = append(tasks, task)
 	}
 
 	return tasks, nil
 }
 
-func catalogPackagesTask(src source.Source) powerUserTask {
+func catalogPackagesTask() (powerUserTask, error) {
 	if !appConfig.Package.Cataloger.Enabled {
-		return nil
+		return nil, nil
 	}
 
-	task := func(results *poweruser.JSONDocumentConfig) error {
+	task := func(results *poweruser.JSONDocumentConfig, src source.Source) error {
 		packageCatalog, theDistro, err := syft.CatalogPackages(src, appConfig.Package.Cataloger.ScopeOpt)
 		if err != nil {
 			return err
@@ -53,21 +48,23 @@ func catalogPackagesTask(src source.Source) powerUserTask {
 		return nil
 	}
 
-	return task
+	return task, nil
 }
 
-func catalogFileMetadataTask(src source.Source) (powerUserTask, error) {
+func catalogFileMetadataTask() (powerUserTask, error) {
 	if !appConfig.FileMetadata.Cataloger.Enabled {
 		return nil, nil
 	}
 
+	metadataCataloger := file.NewMetadataCataloger()
+
+	task := func(results *poweruser.JSONDocumentConfig, src source.Source) error {
 		resolver, err := src.FileResolver(appConfig.FileMetadata.Cataloger.ScopeOpt)
 		if err != nil {
-		return nil, err
+			return err
 		}
 
-	task := func(results *poweruser.JSONDocumentConfig) error {
+		result, err := metadataCataloger.Catalog(resolver)
-		result, err := file.NewMetadataCataloger(resolver).Catalog()
 		if err != nil {
 			return err
 		}
@@ -78,23 +75,23 @@ func catalogFileMetadataTask(src source.Source) (powerUserTask, error) {
 	return task, nil
 }
 
-func catalogFileDigestTask(src source.Source) (powerUserTask, error) {
+func catalogFileDigestTask() (powerUserTask, error) {
 	if !appConfig.FileMetadata.Cataloger.Enabled {
 		return nil, nil
 	}
 
+	digestsCataloger, err := file.NewDigestsCataloger(appConfig.FileMetadata.Digests)
+	if err != nil {
+		return nil, err
+	}
+
+	task := func(results *poweruser.JSONDocumentConfig, src source.Source) error {
 		resolver, err := src.FileResolver(appConfig.FileMetadata.Cataloger.ScopeOpt)
 		if err != nil {
-		return nil, err
+			return err
 		}
 
-	cataloger, err := file.NewDigestsCataloger(resolver, appConfig.FileMetadata.Digests)
+		result, err := digestsCataloger.Catalog(resolver)
-	if err != nil {
-		return nil, err
-	}
-
-	task := func(results *poweruser.JSONDocumentConfig) error {
-		result, err := cataloger.Catalog()
 		if err != nil {
 			return err
 		}