feat: Add Lua cataloger (#2613)

Signed-off-by: Laurent Goderre <laurent.goderre@docker.com>

syft/pkg/cataloger/lua/parse_rockspec.go

@@ -0,0 +1,80 @@
+package lua
+
+import (
+	"context"
+	"strings"
+
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/syft/artifact"
+	"github.com/anchore/syft/syft/file"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/pkg/cataloger/generic"
+)
+
+type luaRocksPackage struct {
+	Name         string
+	Version      string
+	License      string
+	Homepage     string
+	Description  string
+	Dependencies map[string]string
+	Repository   repository
+}
+
+type repository struct {
+	URL string
+}
+
+// parseRockspec parses a package.rockspec and returns the discovered Lua packages.
+func parseRockspec(_ context.Context, _ file.Resolver, _ *generic.Environment, reader file.LocationReadCloser) ([]pkg.Package, []artifact.Relationship, error) {
+	doc, err := parseRockspecData(reader)
+	if err != nil {
+		log.WithFields("error", err).Trace("unable to parse Rockspec app")
+		return nil, nil, nil
+	}
+
+	var name, version, license, homepage, description, url string
+
+	for _, node := range doc.value {
+		switch node.key {
+		case "package":
+			name = node.String()
+		case "version":
+			version = node.String()
+		case "source":
+			for _, child := range node.Slice() {
+				if child.key == "url" {
+					url = child.String()
+					break
+				}
+			}
+		case "description":
+			for _, child := range node.Slice() {
+				switch child.key {
+				case "summary":
+					description = child.String()
+				case "homepage":
+					homepage = child.String()
+				case "license":
+					license = strings.ReplaceAll(child.String(), " ", "-")
+				}
+			}
+		}
+	}
+
+	p := newLuaRocksPackage(
+		luaRocksPackage{
+			Name:    name,
+			Version: version,
+			License: license,
+			Repository: repository{
+				URL: url,
+			},
+			Homepage:    homepage,
+			Description: description,
+		},
+		reader.Location.WithAnnotation(pkg.EvidenceAnnotationKey, pkg.PrimaryEvidenceAnnotation),
+	)
+
+	return []pkg.Package{p}, nil, nil
+}