Tag 0.14.7

Add unit tests, consume imagehashtree in compiler and cleanup

Fixes: #203

cmd/build.go

@@ -247,11 +247,12 @@ Build packages specifying multiple definition trees:
 			}
 
 			for _, sp := range toCalculate {
-				packs, err := luetCompiler.ComputeDepTree(sp)
+				ht := compiler.NewHashTree(generalRecipe.GetDatabase())
+				hashTree, err := ht.Query(luetCompiler, sp)
 				if err != nil {
 					errs = append(errs, err)
 				}
-				for _, p := range packs {
+				for _, p := range hashTree.Dependencies {
 					results.Packages = append(results.Packages,
 						PackageResult{
 							Name:       p.Package.GetName(),

cmd/root.go

@@ -40,7 +40,7 @@ var Verbose bool
 var LockedCommands = []string{"install", "uninstall", "upgrade"}
 
 const (
-	LuetCLIVersion = "0.14.5"
+	LuetCLIVersion = "0.14.7"
 	LuetEnvPrefix  = "LUET"
 )
 
@@ -97,7 +97,7 @@ To build a package, from a tree definition:
 
 		plugin := viper.GetStringSlice("plugin")
 
-		bus.Manager.Load(plugin...).Register()
+		bus.Manager.Initialize(plugin...)
 		if len(bus.Manager.Plugins) != 0 {
 			Info(":lollipop:Enabled plugins:")
 			for _, p := range bus.Manager.Plugins {

pkg/bus/events.go

@@ -1,6 +1,8 @@
 package bus
 
 import (
+	. "github.com/mudler/luet/pkg/logger"
+
 	"github.com/mudler/go-pluggable"
 )
 
@@ -47,21 +49,47 @@ var (
 )
 
 // Manager is the bus instance manager, which subscribes plugins to events emitted by Luet
-var Manager *pluggable.Manager = pluggable.NewManager(
+var Manager *Bus = &Bus{
-	[]pluggable.EventType{
+	Manager: pluggable.NewManager(
-		EventPackageInstall,
+		[]pluggable.EventType{
-		EventPackageUnInstall,
+			EventPackageInstall,
-		EventPackagePreBuild,
+			EventPackageUnInstall,
-		EventPackagePreBuildArtifact,
+			EventPackagePreBuild,
-		EventPackagePostBuildArtifact,
+			EventPackagePreBuildArtifact,
-		EventPackagePostBuild,
+			EventPackagePostBuildArtifact,
-		EventRepositoryPreBuild,
+			EventPackagePostBuild,
-		EventRepositoryPostBuild,
+			EventRepositoryPreBuild,
-		EventImagePreBuild,
+			EventRepositoryPostBuild,
-		EventImagePrePull,
+			EventImagePreBuild,
-		EventImagePrePush,
+			EventImagePrePull,
-		EventImagePostBuild,
+			EventImagePrePush,
-		EventImagePostPull,
+			EventImagePostBuild,
-		EventImagePostPush,
+			EventImagePostPull,
-	},
+			EventImagePostPush,
-)
+		},
+	),
+}
+
+type Bus struct {
+	*pluggable.Manager
+}
+
+func (b *Bus) Initialize(plugin ...string) {
+	b.Manager.Load(plugin...).Register()
+
+	for _, e := range b.Manager.Events {
+		b.Manager.Response(e, func(p *pluggable.Plugin, r *pluggable.EventResponse) {
+			if r.Errored() {
+				Fatal("Plugin", p.Name, "at", p.Executable, "Error", r.Error)
+			}
+			Debug(
+				"plugin_event",
+				"received from",
+				p.Name,
+				"at",
+				p.Executable,
+				r,
+			)
+		})
+	}
+}

pkg/compiler/compiler.go

@@ -146,11 +146,6 @@ func (cs *LuetCompiler) CompileParallel(keepPermissions bool, ps *compilerspec.L
 	}
 
 	for _, p := range ps.All() {
-		asserts, err := cs.ComputeDepTree(p)
-		if err != nil {
-			panic(err)
-		}
-		p.SetSourceAssertion(asserts)
 		all <- p
 	}
 
@@ -295,17 +290,6 @@ func (cs *LuetCompiler) unpackDelta(concurrency int, keepPermissions bool, p *co
 	return artifact, nil
 }
 
-func (cs *LuetCompiler) genBuilderImageTag(p *compilerspec.LuetCompilationSpec, packageImage string) string {
-	// Use packageImage as salt into the fp being used
-	// so the hash is unique also in cases where
-	// some package deps does have completely different
-	// depgraphs
-	// TODO: We should use the image tag, or pass by the package assertion hash which is unique
-	// and identifies the deptree of the package.
-	return fmt.Sprintf("builder-%s", p.GetPackage().HashFingerprint(helpers.StripRegistryFromImage(packageImage)))
-
-}
-
 func (cs *LuetCompiler) buildPackageImage(image, buildertaggedImage, packageImage string,
 	concurrency int, keepPermissions bool,
 	p *compilerspec.LuetCompilationSpec) (backend.Options, backend.Options, error) {
@@ -680,33 +664,7 @@ func (cs *LuetCompiler) FromDatabase(db pkg.PackageDatabase, minimum bool, dst s
 	}
 }
 
-// ComputeMinimumCompilableSet strips specs that are eventually compiled by leafs
-func (cs *LuetCompiler) ComputeMinimumCompilableSet(p ...*compilerspec.LuetCompilationSpec) ([]*compilerspec.LuetCompilationSpec, error) {
-	// Generate a set with all the deps of the provided specs
-	// we will use that set to remove the deps from the list of provided compilation specs
-	allDependencies := solver.PackagesAssertions{} // Get all packages that will be in deps
-	result := []*compilerspec.LuetCompilationSpec{}
-	for _, spec := range p {
-		ass, err := cs.ComputeDepTree(spec)
-		if err != nil {
-			return result, errors.Wrap(err, "computin specs deptree")
-		}
-
-		allDependencies = append(allDependencies, ass.Drop(spec.GetPackage())...)
-	}
-
-	for _, spec := range p {
-		if found := allDependencies.Search(spec.GetPackage().GetFingerPrint()); found == nil {
-			result = append(result, spec)
-		}
-	}
-	return result, nil
-}
-
-// ComputeDepTree computes the dependency tree of a compilation spec and returns solver assertions
-// in order to be able to compile the spec.
 func (cs *LuetCompiler) ComputeDepTree(p *compilerspec.LuetCompilationSpec) (solver.PackagesAssertions, error) {
-
 	s := solver.NewResolver(cs.Options.SolverOptions.Options, pkg.NewInMemoryDatabase(false), cs.Database, pkg.NewInMemoryDatabase(false), cs.Options.SolverOptions.Resolver())
 
 	solution, err := s.Install(pkg.Packages{p.GetPackage()})
@@ -718,31 +676,34 @@ func (cs *LuetCompiler) ComputeDepTree(p *compilerspec.LuetCompilationSpec) (sol
 	if err != nil {
 		return nil, errors.Wrap(err, "While order a solution for "+p.GetPackage().HumanReadableString())
 	}
+	return dependencies, nil
+}
 
-	assertions := solver.PackagesAssertions{}
+// ComputeMinimumCompilableSet strips specs that are eventually compiled by leafs
-	for _, assertion := range dependencies { //highly dependent on the order
+func (cs *LuetCompiler) ComputeMinimumCompilableSet(p ...*compilerspec.LuetCompilationSpec) ([]*compilerspec.LuetCompilationSpec, error) {
-		if assertion.Value {
+	// Generate a set with all the deps of the provided specs
-			nthsolution := dependencies.Cut(assertion.Package)
+	// we will use that set to remove the deps from the list of provided compilation specs
-			assertion.Hash = solver.PackageHash{
+	allDependencies := solver.PackagesAssertions{} // Get all packages that will be in deps
-				BuildHash:   nthsolution.HashFrom(assertion.Package),
+	result := []*compilerspec.LuetCompilationSpec{}
-				PackageHash: nthsolution.AssertionHash(),
+	for _, spec := range p {
-			}
+		sol, err := cs.ComputeDepTree(spec)
-			assertion.Package.SetTreeDir(p.Package.GetTreeDir())
+		if err != nil {
-			assertions = append(assertions, assertion)
+			return nil, errors.Wrap(err, "failed querying hashtree")
+		}
+		allDependencies = append(allDependencies, sol.Drop(spec.GetPackage())...)
+	}
+
+	for _, spec := range p {
+		if found := allDependencies.Search(spec.GetPackage().GetFingerPrint()); found == nil {
+			result = append(result, spec)
 		}
 	}
-	p.SetSourceAssertion(assertions)
+	return result, nil
-	return assertions, nil
 }
 
 // Compile is a non-parallel version of CompileParallel. It builds the compilation specs and generates
 // an artifact
 func (cs *LuetCompiler) Compile(keepPermissions bool, p *compilerspec.LuetCompilationSpec) (*artifact.PackageArtifact, error) {
-	asserts, err := cs.ComputeDepTree(p)
-	if err != nil {
-		return nil, err
-	}
-	p.SetSourceAssertion(asserts)
 	return cs.compile(cs.Options.Concurrency, keepPermissions, p)
 }
 
@@ -773,11 +734,6 @@ func (cs *LuetCompiler) inheritSpecBuildOptions(p *compilerspec.LuetCompilationS
 }
 
 func (cs *LuetCompiler) compile(concurrency int, keepPermissions bool, p *compilerspec.LuetCompilationSpec) (*artifact.PackageArtifact, error) {
-	// TODO: Racy, remove it
-	// Inherit build options from compilation specs metadata
-	// orig := cs.Options.PullImageRepository
-	// defer func() { cs.Options.PullImageRepository = orig }()
-
 	Info(":package: Compiling", p.GetPackage().HumanReadableString(), ".... :coffee:")
 
 	Debug(fmt.Sprintf("%s: has images %t, empty package: %t", p.GetPackage().HumanReadableString(), p.HasImageSource(), p.EmptyPackage()))
@@ -789,36 +745,42 @@ func (cs *LuetCompiler) compile(concurrency int, keepPermissions bool, p *compil
 			)
 	}
 
-	targetAssertion := p.GetSourceAssertion().Search(p.GetPackage().GetFingerPrint())
+	ht := NewHashTree(cs.Database)
+
+	packageHashTree, err := ht.Query(cs, p)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed querying hashtree")
+	}
+
+	// This is in order to have the metadata in the yaml
+	p.SetSourceAssertion(packageHashTree.Solution)
+	targetAssertion := packageHashTree.Target
 
 	bus.Manager.Publish(bus.EventPackagePreBuild, struct {
-		CompileSpec *compilerspec.LuetCompilationSpec
+		CompileSpec     *compilerspec.LuetCompilationSpec
-		Assert      solver.PackageAssert
+		Assert          solver.PackageAssert
+		PackageHashTree *PackageImageHashTree
 	}{
-		CompileSpec: p,
+		CompileSpec:     p,
-		Assert:      *targetAssertion,
+		Assert:          *targetAssertion,
+		PackageHashTree: packageHashTree,
 	})
 
 	// Update compilespec build options - it will be then serialized into the compilation metadata file
-	//p.SetBuildOptions(cs.Options)
 	p.BuildOptions.PushImageRepository = cs.Options.PushImageRepository
-	//p.BuildOptions.BuildValues = cs.Options.BuildValues
-	//p.BuildOptions.BuildValuesFile = cs.Options.BuildValuesFile
 
 	// - If image is set we just generate a plain dockerfile
 	// Treat last case (easier) first. The image is provided and we just compute a plain dockerfile with the images listed as above
 	if p.GetImage() != "" {
-		return cs.compileWithImage(p.GetImage(), cs.genBuilderImageTag(p, targetAssertion.Hash.PackageHash), targetAssertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, p, true)
+		return cs.compileWithImage(p.GetImage(), packageHashTree.BuilderImageHash, targetAssertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, p, true)
 	}
 
 	// - If image is not set, we read a base_image. Then we will build one image from it to kick-off our build based
 	// on how we compute the resolvable tree.
 	// This means to recursively build all the build-images needed to reach that tree part.
 	// - We later on compute an hash used to identify the image, so each similar deptree keeps the same build image.
-
+	dependencies := packageHashTree.Dependencies  // at this point we should have a flattened list of deps to build, including all of them (with all constraints propagated already)
-	dependencies := p.GetSourceAssertion().Drop(p.GetPackage()) // at this point we should have a flattened list of deps to build, including all of them (with all constraints propagated already)
+	departifacts := []*artifact.PackageArtifact{} // TODO: Return this somehow
-	departifacts := []*artifact.PackageArtifact{}               // TODO: Return this somehow
-	var lastHash string
 	depsN := 0
 	currentN := 0
 
@@ -845,8 +807,6 @@ func (cs *LuetCompiler) compile(concurrency int, keepPermissions bool, p *compil
 			Debug("PullImage repos:", compileSpec.BuildOptions.PullImageRepository)
 
 			compileSpec.SetOutputPath(p.GetOutputPath())
-			Debug(pkgTag, "    :arrow_right_hook: :whale: Builder image from hash", assertion.Hash.BuildHash)
-			Debug(pkgTag, "    :arrow_right_hook: :whale: Package image from hash", assertion.Hash.PackageHash)
 
 			bus.Manager.Publish(bus.EventPackagePreBuild, struct {
 				CompileSpec *compilerspec.LuetCompilationSpec
@@ -856,29 +816,43 @@ func (cs *LuetCompiler) compile(concurrency int, keepPermissions bool, p *compil
 				Assert:      assertion,
 			})
 
-			lastHash = assertion.Hash.PackageHash
+			buildHash, err := packageHashTree.DependencyBuildImage(assertion.Package)
-			// for the source instead, pick an image and a buildertaggedImage from hashes if they exists.
+			if err != nil {
-			// otherways fallback to the pushed repo
+				return nil, errors.Wrap(err, "failed looking for dependency in hashtree")
-			// Resolve images from the hashtree
-			resolvedBuildImage := cs.resolveExistingImageHash(assertion.Hash.BuildHash, compileSpec)
-			if compileSpec.GetImage() != "" {
-				Debug(pkgTag, " :wrench: Compiling "+compileSpec.GetPackage().HumanReadableString()+" from image")
-
-				a, err := cs.compileWithImage(compileSpec.GetImage(), assertion.Hash.BuildHash, assertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, compileSpec, packageDeps)
-				if err != nil {
-					return nil, errors.Wrap(err, "Failed compiling "+compileSpec.GetPackage().HumanReadableString())
-				}
-				departifacts = append(departifacts, a)
-				Info(pkgTag, ":white_check_mark: Done")
-				continue
 			}
 
-			Debug(pkgTag, " :wrench: Compiling "+compileSpec.GetPackage().HumanReadableString()+" from tree")
+			Debug(pkgTag, "    :arrow_right_hook: :whale: Builder image from hash", assertion.Hash.BuildHash)
-			a, err := cs.compileWithImage(resolvedBuildImage, cs.genBuilderImageTag(compileSpec, targetAssertion.Hash.PackageHash), assertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, compileSpec, packageDeps)
+			Debug(pkgTag, "    :arrow_right_hook: :whale: Package image from hash", assertion.Hash.PackageHash)
+
+			var sourceImage string
+
+			if compileSpec.GetImage() != "" {
+				Debug(pkgTag, " :wrench: Compiling "+compileSpec.GetPackage().HumanReadableString()+" from image")
+				sourceImage = compileSpec.GetImage()
+			} else {
+				// for the source instead, pick an image and a buildertaggedImage from hashes if they exists.
+				// otherways fallback to the pushed repo
+				// Resolve images from the hashtree
+				sourceImage = cs.resolveExistingImageHash(assertion.Hash.BuildHash, compileSpec)
+				Debug(pkgTag, " :wrench: Compiling "+compileSpec.GetPackage().HumanReadableString()+" from tree")
+			}
+
+			a, err := cs.compileWithImage(
+				sourceImage,
+				buildHash,
+				assertion.Hash.PackageHash,
+				concurrency,
+				keepPermissions,
+				cs.Options.KeepImg,
+				compileSpec,
+				packageDeps,
+			)
 			if err != nil {
 				return nil, errors.Wrap(err, "Failed compiling "+compileSpec.GetPackage().HumanReadableString())
 			}
 
+			Info(pkgTag, ":white_check_mark: Done")
+
 			bus.Manager.Publish(bus.EventPackagePostBuild, struct {
 				CompileSpec *compilerspec.LuetCompilationSpec
 				Artifact    *artifact.PackageArtifact
@@ -888,18 +862,14 @@ func (cs *LuetCompiler) compile(concurrency int, keepPermissions bool, p *compil
 			})
 
 			departifacts = append(departifacts, a)
-			Info(pkgTag, ":white_check_mark: Done")
 		}
-
-	} else if len(dependencies) > 0 {
-		lastHash = dependencies[len(dependencies)-1].Hash.PackageHash
 	}
 
 	if buildTarget {
-		resolvedBuildImage := cs.resolveExistingImageHash(lastHash, p)
+		resolvedSourceImage := cs.resolveExistingImageHash(packageHashTree.SourceHash, p)
 		Info(":rocket: All dependencies are satisfied, building package requested by the user", p.GetPackage().HumanReadableString())
-		Info(":package:", p.GetPackage().HumanReadableString(), " Using image: ", resolvedBuildImage)
+		Info(":package:", p.GetPackage().HumanReadableString(), " Using image: ", resolvedSourceImage)
-		a, err := cs.compileWithImage(resolvedBuildImage, cs.genBuilderImageTag(p, targetAssertion.Hash.PackageHash), targetAssertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, p, true)
+		a, err := cs.compileWithImage(resolvedSourceImage, packageHashTree.BuilderImageHash, targetAssertion.Hash.PackageHash, concurrency, keepPermissions, cs.Options.KeepImg, p, true)
 		if err != nil {
 			return a, err
 		}

pkg/compiler/imagehashtree.go

@@ -0,0 +1,126 @@
+// Copyright © 2021 Ettore Di Giacinto <mudler@mocaccino.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/>.
+
+package compiler
+
+import (
+	"fmt"
+
+	compilerspec "github.com/mudler/luet/pkg/compiler/types/spec"
+	"github.com/mudler/luet/pkg/config"
+	pkg "github.com/mudler/luet/pkg/package"
+	"github.com/mudler/luet/pkg/solver"
+	"github.com/pkg/errors"
+)
+
+type ImageHashTree struct {
+	Database      pkg.PackageDatabase
+	SolverOptions config.LuetSolverOptions
+}
+
+type PackageImageHashTree struct {
+	Target                       *solver.PackageAssert
+	Dependencies                 solver.PackagesAssertions
+	Solution                     solver.PackagesAssertions
+	dependencyBuilderImageHashes map[string]string
+	SourceHash                   string
+	BuilderImageHash             string
+}
+
+func NewHashTree(db pkg.PackageDatabase) *ImageHashTree {
+	return &ImageHashTree{
+		Database: db,
+	}
+}
+
+func (ht *PackageImageHashTree) DependencyBuildImage(p pkg.Package) (string, error) {
+	found, ok := ht.dependencyBuilderImageHashes[p.GetFingerPrint()]
+	if !ok {
+		return "", errors.New("package hash not found")
+	}
+	return found, nil
+}
+
+// TODO: ___ When computing the hash per package (and evaluating the sat solver solution tree part)
+// we should use the hash of each package  + its fingerprint  instead as a salt.
+// That's because the hash will be salted with its `build.yaml`.
+// In this way, we trigger recompilations if some dep of a target changes
+// a build.yaml, without touching the version
+func (ht *ImageHashTree) Query(cs *LuetCompiler, p *compilerspec.LuetCompilationSpec) (*PackageImageHashTree, error) {
+	assertions, err := ht.resolve(cs, p)
+	if err != nil {
+		return nil, err
+	}
+	targetAssertion := assertions.Search(p.GetPackage().GetFingerPrint())
+
+	dependencies := assertions.Drop(p.GetPackage())
+	var sourceHash string
+	imageHashes := map[string]string{}
+	for _, assertion := range dependencies {
+		var depbuildImageTag string
+		compileSpec, err := cs.FromPackage(assertion.Package)
+		if err != nil {
+			return nil, errors.Wrap(err, "Error while generating compilespec for "+assertion.Package.GetName())
+		}
+		if compileSpec.GetImage() != "" {
+			depbuildImageTag = assertion.Hash.BuildHash
+		} else {
+			depbuildImageTag = ht.genBuilderImageTag(compileSpec, targetAssertion.Hash.PackageHash)
+		}
+		imageHashes[assertion.Package.GetFingerPrint()] = depbuildImageTag
+		sourceHash = assertion.Hash.PackageHash
+	}
+
+	return &PackageImageHashTree{
+		Dependencies:                 dependencies,
+		Target:                       targetAssertion,
+		SourceHash:                   sourceHash,
+		BuilderImageHash:             ht.genBuilderImageTag(p, targetAssertion.Hash.PackageHash),
+		dependencyBuilderImageHashes: imageHashes,
+		Solution:                     assertions,
+	}, nil
+}
+
+func (ht *ImageHashTree) genBuilderImageTag(p *compilerspec.LuetCompilationSpec, packageImage string) string {
+	// Use packageImage as salt into the fp being used
+	// so the hash is unique also in cases where
+	// some package deps does have completely different
+	// depgraphs
+	return fmt.Sprintf("builder-%s", p.GetPackage().HashFingerprint(packageImage))
+}
+
+// resolve computes the dependency tree of a compilation spec and returns solver assertions
+// in order to be able to compile the spec.
+func (ht *ImageHashTree) resolve(cs *LuetCompiler, p *compilerspec.LuetCompilationSpec) (solver.PackagesAssertions, error) {
+	dependencies, err := cs.ComputeDepTree(p)
+	if err != nil {
+		return nil, errors.Wrap(err, "While computing a solution for "+p.GetPackage().HumanReadableString())
+	}
+
+	assertions := solver.PackagesAssertions{}
+	for _, assertion := range dependencies { //highly dependent on the order
+		if assertion.Value {
+			nthsolution := dependencies.Cut(assertion.Package)
+			assertion.Hash = solver.PackageHash{
+				BuildHash:   nthsolution.HashFrom(assertion.Package),
+				PackageHash: nthsolution.AssertionHash(),
+			}
+			assertion.Package.SetTreeDir(p.Package.GetTreeDir())
+			assertions = append(assertions, assertion)
+		}
+	}
+
+	return assertions, nil
+}

pkg/compiler/imagehashtree_test.go

@@ -0,0 +1,94 @@
+// Copyright © 2021 Ettore Di Giacinto <mudler@mocaccino.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/>.
+
+package compiler_test
+
+import (
+	. "github.com/mudler/luet/pkg/compiler"
+	sd "github.com/mudler/luet/pkg/compiler/backend"
+	"github.com/mudler/luet/pkg/compiler/types/options"
+	pkg "github.com/mudler/luet/pkg/package"
+	"github.com/mudler/luet/pkg/tree"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("ImageHashTree", func() {
+	generalRecipe := tree.NewCompilerRecipe(pkg.NewInMemoryDatabase(false))
+	compiler := NewLuetCompiler(sd.NewSimpleDockerBackend(), generalRecipe.GetDatabase(), options.Concurrency(2))
+	hashtree := NewHashTree(generalRecipe.GetDatabase())
+	Context("Simple package definition", func() {
+		BeforeEach(func() {
+			generalRecipe = tree.NewCompilerRecipe(pkg.NewInMemoryDatabase(false))
+			err := generalRecipe.Load("../../tests/fixtures/buildable")
+			Expect(err).ToNot(HaveOccurred())
+			compiler = NewLuetCompiler(sd.NewSimpleDockerBackend(), generalRecipe.GetDatabase(), options.Concurrency(2))
+			hashtree = NewHashTree(generalRecipe.GetDatabase())
+
+		})
+
+		It("Calculates the hash correctly", func() {
+
+			spec, err := compiler.FromPackage(&pkg.DefaultPackage{Name: "b", Category: "test", Version: "1.0"})
+			Expect(err).ToNot(HaveOccurred())
+
+			packageHash, err := hashtree.Query(compiler, spec)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(packageHash.Target.Hash.BuildHash).To(Equal("6490e800fe443b99328fc363529aee74bda513930fb27ce6ab814d692bba068e"))
+			Expect(packageHash.Target.Hash.PackageHash).To(Equal("79d7107d13d578b362e6a7bf10ec850efce26316405b8d732ce8f9e004d64281"))
+			Expect(packageHash.BuilderImageHash).To(Equal("builder-79462b60bf899ad79db63f194a3c9c2a"))
+		})
+	})
+
+	Context("complex package definition", func() {
+		BeforeEach(func() {
+			generalRecipe = tree.NewCompilerRecipe(pkg.NewInMemoryDatabase(false))
+
+			err := generalRecipe.Load("../../tests/fixtures/upgrade_old_repo_revision")
+			Expect(err).ToNot(HaveOccurred())
+			compiler = NewLuetCompiler(sd.NewSimpleDockerBackend(), generalRecipe.GetDatabase(), options.Concurrency(2))
+			hashtree = NewHashTree(generalRecipe.GetDatabase())
+
+		})
+		It("Calculates the hash correctly", func() {
+			spec, err := compiler.FromPackage(&pkg.DefaultPackage{Name: "c", Category: "test", Version: "1.0"})
+			Expect(err).ToNot(HaveOccurred())
+
+			packageHash, err := hashtree.Query(compiler, spec)
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(packageHash.Dependencies[len(packageHash.Dependencies)-1].Hash.PackageHash).To(Equal("c46e653125d71ee3fd696b3941ec1ed6e8a0268f896204c7a222a5aa03eb9982"))
+			Expect(packageHash.SourceHash).To(Equal("c46e653125d71ee3fd696b3941ec1ed6e8a0268f896204c7a222a5aa03eb9982"))
+			Expect(packageHash.BuilderImageHash).To(Equal("builder-37f4d05ba8a39525742ca364f69b4090"))
+
+			//Expect(packageHash.Target.Hash.BuildHash).To(Equal("79d7107d13d578b362e6a7bf10ec850efce26316405b8d732ce8f9e004d64281"))
+			Expect(packageHash.Target.Hash.PackageHash).To(Equal("bb1d9a99c0c309a297c75b436504e664a42121fadbb4e035bda403cd418117aa"))
+			a := &pkg.DefaultPackage{Name: "a", Category: "test", Version: "1.1"}
+			hash, err := packageHash.DependencyBuildImage(a)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(hash).To(Equal("79d7107d13d578b362e6a7bf10ec850efce26316405b8d732ce8f9e004d64281"))
+
+			assertionA := packageHash.Dependencies.Search(a.GetFingerPrint())
+			Expect(assertionA.Hash.PackageHash).To(Equal("c46e653125d71ee3fd696b3941ec1ed6e8a0268f896204c7a222a5aa03eb9982"))
+			b := &pkg.DefaultPackage{Name: "b", Category: "test", Version: "1.0"}
+			assertionB := packageHash.Dependencies.Search(b.GetFingerPrint())
+			Expect(assertionB.Hash.PackageHash).To(Equal("79d7107d13d578b362e6a7bf10ec850efce26316405b8d732ce8f9e004d64281"))
+			hashB, err := packageHash.DependencyBuildImage(b)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(hashB).To(Equal("6490e800fe443b99328fc363529aee74bda513930fb27ce6ab814d692bba068e"))
+		})
+	})
+
+})

pkg/compiler/types/artifact/artifact.go

@@ -390,15 +390,15 @@ func tarModifierWrapperFunc(dst, path string, header *tar.Header, content io.Rea
 		f, err := os.Lstat(destPath)
 		if err == nil {
 			Debug("File exists already, computing hash for", destPath)
-			hash, err := hashFileContent(destPath)
+			hash, herr := hashFileContent(destPath)
-			if err == nil {
+			if herr == nil {
 				existingHash = hash
 			}
 		}
 
 		Debug("Existing file hash: ", existingHash, "Tar file hashsum: ", tarHash)
 		// We want to protect file only if the hash of the files are differing OR the file size are
-		differs := (existingHash != "" && existingHash != tarHash) || header.Size != f.Size()
+		differs := (existingHash != "" && existingHash != tarHash) || (err != nil && f != nil && header.Size != f.Size())
 		// Check if exists
 		if helpers.Exists(destPath) && differs {
 			for i := 1; i < 1000; i++ {

pkg/compiler/types/spec/spec.go

@@ -16,6 +16,7 @@
 package compilerspec
 
 import (
+	"fmt"
 	"io/ioutil"
 	"path/filepath"
 
@@ -85,6 +86,13 @@ func (specs *LuetCompilationspecs) Unique() *LuetCompilationspecs {
 	return &newSpecs
 }
 
+type CopyField struct {
+	Package     *pkg.DefaultPackage `json:"package"`
+	Image       string              `json:"image"`
+	Source      string              `json:"src"`
+	Destination string              `json:"dst"`
+}
+
 type LuetCompilationSpec struct {
 	Steps           []string                  `json:"steps"` // Are run inside a container and the result layer diff is saved
 	Env             []string                  `json:"env"`
@@ -103,6 +111,8 @@ type LuetCompilationSpec struct {
 	Excludes   []string `json:"excludes"`
 
 	BuildOptions *options.Compiler `json:"build_options"`
+
+	Copy []CopyField `json:"copy"`
 }
 
 func NewLuetCompilationSpec(b []byte, p pkg.Package) (*LuetCompilationSpec, error) {
@@ -256,6 +266,12 @@ ADD ` + s + ` /luetbuild/`
 		}
 	}
 
+	for _, c := range cs.Copy {
+		if c.Image != "" {
+			spec = spec + fmt.Sprintf("\nCOPY --from=%s %s %s\n", c.Image, c.Source, c.Destination)
+		}
+	}
+
 	for _, s := range cs.Env {
 		spec = spec + `
 ENV ` + s

tests/fixtures/plugin/test-foo

@@ -1,3 +1,5 @@
 #!/bin/bash
 echo "$1" >> $EVENT_FILE
-echo "$2" >> $PAYLOAD_FILE
+echo "$2" >> $PAYLOAD_FILE
+
+echo "{}"