Source packages metadata to update repository tree

This allows to generate trees with `create-repo` by just having
the metadata files, making tree(s) an optional requirement.

pkg/installer/repository.go

@@ -24,6 +24,7 @@ import (
 	"regexp"
 	"sort"
 	"strconv"
+	"strings"
 	"time"
 
 	artifact "github.com/mudler/luet/pkg/compiler/types/artifact"
@@ -297,6 +298,37 @@ func GenerateRepository(name, descr, t string, urls []string,
 		}
 	}
 
+	// Load packages from metadata files if not present already.
+	var ff = func(currentpath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return nil
+		}
+
+		// Only those which are metadata
+		if !strings.HasSuffix(info.Name(), pkg.PackageMetaSuffix) {
+			return nil
+		}
+
+		dat, err := ioutil.ReadFile(currentpath)
+		if err != nil {
+			return nil
+		}
+
+		art, err := artifact.NewPackageArtifactFromYaml(dat)
+		if err != nil {
+			return nil
+		}
+		if _, err := runtimeTree.FindPackage(art.CompileSpec.Package); err != nil && art.CompileSpec.Package.Name != "" {
+			Debug("Added", art.CompileSpec.Package.HumanReadableString(), "from metadata files")
+			runtimeTree.CreatePackage(art.CompileSpec.Package)
+		}
+
+		return nil
+	}
+
+	// Best effort
+	filepath.Walk(src, ff)
+
 	repo := &LuetSystemRepository{
 		LuetRepository:  config.NewLuetRepository(name, t, descr, urls, priority, true, false),
 		Tree:            tree.NewInstallerRecipe(runtimeTree),

pkg/package/package.go

@@ -124,6 +124,8 @@ type Package interface {
 	JSON() ([]byte, error)
 }
 
+const PackageMetaSuffix = "metadata.yaml"
+
 type Tree interface {
 	GetPackageSet() PackageDatabase
 	Prelude() string // A tree might have a prelude to be able to consume a tree
@@ -246,7 +248,7 @@ func (t *DefaultPackage) JSON() ([]byte, error) {
 
 // GetMetadataFilePath returns the canonical name of an artifact metadata file
 func (d *DefaultPackage) GetMetadataFilePath() string {
-	return d.GetFingerPrint() + ".metadata.yaml"
+	return fmt.Sprintf("%s.%s", d.GetFingerPrint(), PackageMetaSuffix)
 }
 
 // DefaultPackage represent a standard package definition