[CPP] add Conan conan.lock file support

Signed-off-by: Hiroaki KAWAI <hiroaki.kawai@gmail.com>

syft/pkg/cataloger/cpp/cataloger.go

@@ -8,6 +8,7 @@ import (
 func NewConanfileCataloger() *common.GenericCataloger {
 	globParsers := map[string]common.ParserFn{
 		"**/conanfile.txt": parseConanfile,
+		"**/conan.lock":    parseConanlock,
 	}
 
 	return common.NewGenericCataloger(nil, globParsers, "conan-cataloger")

syft/pkg/cataloger/cpp/parse_conanlock.go

@@ -0,0 +1,52 @@
+package cpp
+
+import (
+	"encoding/json"
+	"io"
+	"strings"
+
+	"github.com/anchore/syft/syft/artifact"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/pkg/cataloger/common"
+)
+
+// integrity check
+var _ common.ParserFn = parseConanlock
+
+// parseConanlock is a parser function for conan.lock contents, returning all packages discovered.
+func parseConanlock(_ string, reader io.Reader) ([]*pkg.Package, []artifact.Relationship, error) {
+	pkgs := []*pkg.Package{}
+	var graphLock struct {
+		GraphLock struct {
+			Nodes map[string]struct {
+				Ref string
+			}
+		} `json:"graph_lock"`
+	}
+	if err := json.NewDecoder(reader).Decode(&graphLock); err != nil {
+		return nil, nil, err
+	} else {
+		for _, node := range graphLock.GraphLock.Nodes {
+			if len(node.Ref) > 0 {
+				// ref: pkga/0.1@user/testing
+				splits := strings.Split(strings.Split(node.Ref, "@")[0], "/")
+				if len(splits) < 2 {
+					continue
+				}
+				pkgName, pkgVersion := splits[0], splits[1]
+				pkgs = append(pkgs, &pkg.Package{
+					Name:         pkgName,
+					Version:      pkgVersion,
+					Language:     pkg.CPP,
+					Type:         pkg.ConanPkg,
+					MetadataType: pkg.ConanaMetadataType,
+					Metadata: pkg.ConanMetadata{
+						Name:    pkgName,
+						Version: pkgVersion,
+					},
+				})
+			}
+		}
+		return pkgs, nil, nil
+	}
+}

syft/pkg/cataloger/cpp/parse_conanlock_test.go

@@ -0,0 +1,42 @@
+package cpp
+
+import (
+	"os"
+	"testing"
+
+	"github.com/go-test/deep"
+
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func TestParseConanlock(t *testing.T) {
+	expected := []*pkg.Package{
+		{
+			Name:         "zlib",
+			Version:      "1.2.12",
+			Language:     pkg.CPP,
+			Type:         pkg.ConanPkg,
+			MetadataType: pkg.ConanaMetadataType,
+			Metadata: pkg.ConanMetadata{
+				Name:    "zlib",
+				Version: "1.2.12",
+			},
+		},
+	}
+
+	fixture, err := os.Open("test-fixtures/conan.lock")
+	if err != nil {
+		t.Fatalf("failed to open fixture: %+v", err)
+	}
+
+	// TODO: no relationships are under test yet
+	actual, _, err := parseConanlock(fixture.Name(), fixture)
+	if err != nil {
+		t.Error(err)
+	}
+
+	differences := deep.Equal(expected, actual)
+	if differences != nil {
+		t.Errorf("returned package list differed from expectation: %+v", differences)
+	}
+}

syft/pkg/cataloger/cpp/test-fixtures/conan.lock

@@ -0,0 +1,15 @@
+{
+ "graph_lock": {
+  "nodes": {
+   "0": {
+    "ref": "zlib/1.2.12",
+    "options": "fPIC=True\nshared=False",
+    "path": "all/conanfile.py",
+    "context": "host"
+   }
+  },
+  "revisions_enabled": false
+ },
+ "version": "0.4",
+ "profile_host": "[settings]\narch=x86_64\narch_build=x86_64\nbuild_type=Release\ncompiler=gcc\ncompiler.libcxx=libstdc++\ncompiler.version=9\nos=Linux\nos_build=Linux\n[options]\n[build_requires]\n[env]\n"
+}