Add Separate tree for build dependency

Reuse the Recipe and extend it to read a separate tree for build
dependencies.

Also add accessors to compilespec to produce dockerfile image format.

pkg/tree/compiler_recipe.go

@@ -0,0 +1,105 @@
+// Copyright © 2019 Ettore Di Giacinto <mudler@gentoo.org>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, see <http://www.gnu.org/licenses/>.
+
+// Recipe is a builder imeplementation.
+
+// It reads a Tree and spit it in human readable form (YAML), called recipe,
+// It also loads a tree (recipe) from a YAML (to a db, e.g. BoltDB), allowing to query it
+// with the solver, using the package object.
+package tree
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/mudler/luet/pkg/helpers"
+	pkg "github.com/mudler/luet/pkg/package"
+	"github.com/pkg/errors"
+)
+
+const (
+	CompilerDefinitionFile = "build.yaml"
+)
+
+func NewCompilerRecipe() Builder { return &CompilerRecipe{} }
+
+// Recipe is the "general" reciper for Trees
+type CompilerRecipe struct {
+	Recipe
+}
+
+func (r *CompilerRecipe) Load(path string) error {
+
+	if r.Tree() == nil {
+		r.PackageTree = NewDefaultTree()
+	}
+
+	tmpfile, err := ioutil.TempFile("", "luet")
+	if err != nil {
+		return err
+	}
+
+	r.Tree().SetPackageSet(pkg.NewBoltDatabase(tmpfile.Name()))
+	// TODO: Handle cleaning after? Cleanup implemented in GetPackageSet().Clean()
+
+	// the function that handles each file or dir
+	var ff = func(currentpath string, info os.FileInfo, err error) error {
+
+		if info.Name() != DefinitionFile {
+			return nil // Skip with no errors
+		}
+
+		dat, err := ioutil.ReadFile(currentpath)
+		if err != nil {
+			return errors.Wrap(err, "Error reading file "+currentpath)
+		}
+		pack, err := pkg.DefaultPackageFromYaml(dat)
+		if err != nil {
+			return errors.Wrap(err, "Error reading yaml "+currentpath)
+		}
+
+		// Path is set only internally when tree is loaded from disk
+		pack.SetPath(filepath.Dir(currentpath))
+
+		// Instead of rdeps, have a different tree for build deps.
+		compileDefPath := pack.Rel(CompilerDefinitionFile)
+		if helpers.Exists(compileDefPath) {
+			dat, err = ioutil.ReadFile(currentpath)
+			if err != nil {
+				return errors.Wrap(err, "Error reading file "+currentpath)
+			}
+			packbuild, err := pkg.DefaultPackageFromYaml(dat)
+			if err != nil {
+				return errors.Wrap(err, "Error reading yaml "+currentpath)
+			}
+			pack.Requires(packbuild.GetRequires())
+			pack.Conflicts(packbuild.GetConflicts())
+		}
+
+		_, err = r.Tree().GetPackageSet().CreatePackage(&pack)
+		if err != nil {
+			return errors.Wrap(err, "Error creating package "+pack.GetName())
+		}
+
+		return nil
+	}
+
+	err = filepath.Walk(path, ff)
+	if err != nil {
+		return err
+	}
+	return nil
+}