add analysis coordination (with dummy analyzer)

imgbom/analyzer/analyzer.go

@@ -2,13 +2,13 @@ package analyzer
 
 import (
 	"github.com/anchore/imgbom/imgbom/pkg"
-	"github.com/anchore/imgbom/imgbom/scope"
 	"github.com/anchore/stereoscope/pkg/file"
+	"github.com/anchore/stereoscope/pkg/tree"
 )
 
 type Analyzer interface {
-	SelectFiles(scope.Scope) []file.Reference
+	SelectFiles([]*tree.FileTree) []file.Reference
 	// NOTE: one of the errors which is returned is "IterationNeeded", which indicates to the driver to
 	// continue with another Select/Analyze pass
-	Analyze(pkg.CatalogWriter, map[file.Reference]string) error
+	Analyze(map[file.Reference]string) ([]pkg.Package, error)
 }

imgbom/analyzer/controller.go

@@ -1,11 +1,24 @@
 package analyzer
 
+import (
+	"github.com/anchore/imgbom/imgbom/analyzer/dummy"
+	"github.com/anchore/imgbom/imgbom/pkg"
+	"github.com/anchore/imgbom/imgbom/scope"
+	"github.com/anchore/stereoscope/pkg/file"
+	"github.com/hashicorp/go-multierror"
+)
+
 var controllerInstance controller
 
 func init() {
 	controllerInstance = controller{
 		analyzers: make([]Analyzer, 0),
 	}
+	controllerInstance.add(dummy.NewAnalyzer())
+}
+
+func Analyze(s scope.Scope) (pkg.Catalog, error) {
+	return controllerInstance.analyze(s)
 }
 
 type controller struct {
@@ -16,6 +29,37 @@ func (c *controller) add(a Analyzer) {
 	c.analyzers = append(c.analyzers, a)
 }
 
-func Add(a Analyzer) {
-	controllerInstance.add(a)
-}
+func (c *controller) analyze(s scope.Scope) (pkg.Catalog, error) {
+	catalog := pkg.NewCatalog()
+	fileSelection := make([]file.Reference, 0)
+
+	// ask analyzers for files to extract from the image tar
+	for _, a := range c.analyzers {
+		fileSelection = append(fileSelection, a.SelectFiles(s.Trees)...)
+	}
+
+	// fetch contents for requested selection by analyzers
+	contents, err := s.Image.MultipleFileContentsByRef(fileSelection...)
+	if err != nil {
+		return pkg.Catalog{}, err
+	}
+
+	// perform analysis, accumulating errors for each failed analysis
+	var errs error
+	for _, a := range c.analyzers {
+		packages, err := a.Analyze(contents)
+		// TODO: check for multiple rounds of analyses by Iterate error
+		if err != nil {
+			errs = multierror.Append(errs, err)
+		}
+		for _, p := range packages {
+			catalog.Add(p)
+		}
+	}
+
+	if errs != nil {
+		return pkg.Catalog{}, errs
+	}
+
+	return catalog, nil
+}

imgbom/analyzer/dummy/analyzer.go

@@ -0,0 +1,30 @@
+package dummy
+
+import (
+	"github.com/anchore/imgbom/imgbom/pkg"
+	"github.com/anchore/stereoscope/pkg/file"
+	"github.com/anchore/stereoscope/pkg/tree"
+)
+
+// TODO: delete me
+
+type Analyzer struct{}
+
+func NewAnalyzer() *Analyzer {
+	return &Analyzer{}
+}
+
+func (a *Analyzer) SelectFiles(trees []*tree.FileTree) []file.Reference {
+	return []file.Reference{*trees[0].File("/etc/centos-release")}
+}
+
+func (a *Analyzer) Analyze(contents map[file.Reference]string) ([]pkg.Package, error) {
+	return []pkg.Package{
+		{
+			Name:     "dummy",
+			Version:  "1.0.0",
+			Type:     pkg.DebPkg,
+			Metadata: pkg.DummyPackage{Extra: "some extra metadata"},
+		},
+	}, nil
+}