ignore target link files based on path (#667)

* ignore target link files based on path

log when files are actually indexed

add test for sym link resolution

golang test nits

Signed-off-by: Jonas Galvão Xavier <jonas.agx@gmail.com>

* nil catalog should act like an empty catalog

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

* remove dir path filtering in favor of file type filtering

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

* split out addPathToIndex into specialized functions

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

* add test for nul catalog enumeration

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

* conditionally discover MIME types for file based on file resolver index

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

* change logging around cataloging

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

* add tests to cover possible infinite symlink loop for resolver

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

Co-authored-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/cataloger/catalog.go

@@ -51,6 +51,7 @@ func Catalog(resolver source.FileResolver, theDistro *distro.Distro, catalogers
 	var errs error
 	for _, theCataloger := range catalogers {
 		// find packages from the underlying raw data
+		log.Debugf("cataloging with %q", theCataloger.Name())
 		packages, relationships, err := theCataloger.Catalog(resolver)
 		if err != nil {
 			errs = multierror.Append(errs, err)
@@ -59,7 +60,7 @@ func Catalog(resolver source.FileResolver, theDistro *distro.Distro, catalogers
 
 		catalogedPackages := len(packages)
 
-		log.Debugf("package cataloger %q discovered %d packages", theCataloger.Name(), catalogedPackages)
+		log.Debugf("discovered %d packages", catalogedPackages)
 		packagesDiscovered.N += int64(catalogedPackages)
 
 		for _, p := range packages {