Define Artifact diffs layers

It also add in simpledocker a naive implementation using the container-diff binary, which is supposed to go away with a proper API implementation.

pkg/compiler/artifact.go

@@ -15,11 +15,6 @@
 
 package compiler
 
-type Artifact interface {
-	GetPath() string
-	SetPath(string)
-}
-
 type PackageArtifact struct {
 	Path string
 }

pkg/compiler/backend/simpledocker.go

@@ -16,6 +16,7 @@
 package backend
 
 import (
+	"encoding/json"
 	"os/exec"
 
 	"github.com/mudler/luet/pkg/compiler"
@@ -37,6 +38,8 @@ func (*SimpleDocker) BuildImage(opts compiler.CompilerBackendOptions) error {
 	dockerfileName := opts.DockerFileName
 	buildarg := []string{"build", "-f", dockerfileName, "-t", name, "."}
 	Spinner(22)
+	defer SpinnerStop()
+
 	Debug("Building image "+name+" - running docker with: ", buildarg)
 	cmd := exec.Command("docker", buildarg...)
 	cmd.Dir = path
@@ -44,7 +47,6 @@ func (*SimpleDocker) BuildImage(opts compiler.CompilerBackendOptions) error {
 	if err != nil {
 		return errors.Wrap(err, "Failed building image: "+string(out))
 	}
-	SpinnerStop()
 	Info(string(out))
 	return nil
 }
@@ -53,11 +55,11 @@ func (*SimpleDocker) RemoveImage(opts compiler.CompilerBackendOptions) error {
 	name := opts.ImageName
 	buildarg := []string{"rmi", name}
 	Spinner(22)
+	defer SpinnerStop()
 	out, err := exec.Command("docker", buildarg...).CombinedOutput()
 	if err != nil {
 		return errors.Wrap(err, "Failed removing image: "+string(out))
 	}
-	SpinnerStop()
 	Info(string(out))
 	return nil
 }
@@ -81,14 +83,59 @@ func (*SimpleDocker) ExportImage(opts compiler.CompilerBackendOptions) error {
 
 	buildarg := []string{"save", name, "-o", path}
 	Spinner(22)
+	defer SpinnerStop()
 	Debug("Saving image "+name+" - running docker with: ", buildarg)
 	out, err := exec.Command("docker", buildarg...).CombinedOutput()
 	if err != nil {
 		return errors.Wrap(err, "Failed exporting image: "+string(out))
 	}
-	SpinnerStop()
+
 	Info(string(out))
 	return nil
 }
 
-// TODO: Use container-diff (https://github.com/GoogleContainerTools/container-diff) for checking out layer diffs
+// 	container-diff diff daemon://luet/base alpine --type=file -j
+// [
+//   {
+//     "Image1": "luet/base",
+//     "Image2": "alpine",
+//     "DiffType": "File",
+//     "Diff": {
+//       "Adds": null,
+//       "Dels": [
+//         {
+//           "Name": "/luetbuild",
+//           "Size": 5830706
+//         },
+//         {
+//           "Name": "/luetbuild/Dockerfile",
+//           "Size": 50
+//         },
+//         {
+//           "Name": "/luetbuild/output1",
+//           "Size": 5830656
+//         }
+//       ],
+//       "Mods": null
+//     }
+//   }
+// ]
+// Changes uses container-diff (https://github.com/GoogleContainerTools/container-diff) for retrieving out layer diffs
+func (*SimpleDocker) Changes(fromImage, toImage string) ([]compiler.ArtifactLayer, error) {
+	diffargs := []string{"diff", fromImage, toImage, "--type=file", "-j"}
+	Spinner(22)
+	defer SpinnerStop()
+
+	out, err := exec.Command("container-diff", diffargs...).CombinedOutput()
+	if err != nil {
+		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed Resolving layer diffs: "+string(out))
+	}
+
+	var diffs []compiler.ArtifactLayer
+
+	err = json.Unmarshal(out, &diffs)
+	if err != nil {
+		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed unmarshalling json response: "+string(out))
+	}
+	return diffs, nil
+}

pkg/compiler/backend/simpledocker_test.go

@@ -55,6 +55,10 @@ var _ = Describe("Docker backend", func() {
 			Expect(err).ToNot(HaveOccurred())
 			defer os.RemoveAll(tmpdir) // clean up
 
+			tmpdir2, err := ioutil.TempDir(os.TempDir(), "tree2")
+			Expect(err).ToNot(HaveOccurred())
+			defer os.RemoveAll(tmpdir2) // clean up
+
 			err = lspec.WriteBuildImageDefinition(filepath.Join(tmpdir, "Dockerfile"))
 			Expect(err).ToNot(HaveOccurred())
 			dockerfile, err := helpers.Read(filepath.Join(tmpdir, "Dockerfile"))
@@ -69,10 +73,10 @@ WORKDIR /luetbuild
 				ImageName:      "luet/base",
 				SourcePath:     tmpdir,
 				DockerFileName: "Dockerfile",
-				Destination:    filepath.Join(tmpdir, "output1"),
+				Destination:    filepath.Join(tmpdir2, "output1.tar"),
 			}
 			Expect(b.ImageDefinitionToTar(opts)).ToNot(HaveOccurred())
-			Expect(helpers.Exists(filepath.Join(tmpdir, "output1"))).To(BeTrue())
+			Expect(helpers.Exists(filepath.Join(tmpdir2, "output1.tar"))).To(BeTrue())
 			Expect(b.BuildImage(opts)).ToNot(HaveOccurred())
 
 			err = lspec.WriteStepImageDefinition(lspec.Image, filepath.Join(tmpdir, "LuetDockerfile"))
@@ -87,10 +91,22 @@ RUN echo bar > /test2`))
 				ImageName:      "test",
 				SourcePath:     tmpdir,
 				DockerFileName: "LuetDockerfile",
-				Destination:    filepath.Join(tmpdir, "output2"),
+				Destination:    filepath.Join(tmpdir, "output2.tar"),
 			}
 			Expect(b.ImageDefinitionToTar(opts)).ToNot(HaveOccurred())
-			Expect(helpers.Exists(filepath.Join(tmpdir, "output2"))).To(BeTrue())
+			Expect(helpers.Exists(filepath.Join(tmpdir, "output2.tar"))).To(BeTrue())
+
+			Expect(b.Changes(filepath.Join(tmpdir2, "output1.tar"), filepath.Join(tmpdir, "output2.tar"))).To(Equal(
+				[]ArtifactLayer{{
+					FromImage: filepath.Join(tmpdir2, "output1.tar"),
+					ToImage:   filepath.Join(tmpdir, "output2.tar"),
+					Diffs: ArtifactDiffs{
+						Additions: []ArtifactNode{
+							{Name: "/test", Size: 4},
+							{Name: "/test2", Size: 4},
+						},
+					},
+				}}))
 
 		})
 

pkg/compiler/backend/simpleimg.go

@@ -16,6 +16,7 @@
 package backend
 
 import (
+	"encoding/json"
 	"os/exec"
 
 	"github.com/mudler/luet/pkg/compiler"
@@ -89,4 +90,25 @@ func (*SimpleImg) ExportImage(opts compiler.CompilerBackendOptions) error {
 	return nil
 }
 
+// TODO: Dup in docker, refactor common code in helpers for shared parts
+
 // TODO: Use container-diff (https://github.com/GoogleContainerTools/container-diff) for checking out layer diffs
+// Changes uses container-diff (https://github.com/GoogleContainerTools/container-diff) for retrieving out layer diffs
+func (*SimpleImg) Changes(fromImage, toImage string) ([]compiler.ArtifactLayer, error) {
+	diffargs := []string{"diff", fromImage, toImage, "--type=file", "-j"}
+	Spinner(22)
+	defer SpinnerStop()
+
+	out, err := exec.Command("container-diff", diffargs...).CombinedOutput()
+	if err != nil {
+		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed Resolving layer diffs: "+string(out))
+	}
+
+	var diffs []compiler.ArtifactLayer
+
+	err = json.Unmarshal(out, &diffs)
+	if err != nil {
+		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed unmarshalling json response: "+string(out))
+	}
+	return diffs, nil
+}

pkg/compiler/interface.go

@@ -15,7 +15,9 @@
 
 package compiler
 
-import pkg "github.com/mudler/luet/pkg/package"
+import (
+	pkg "github.com/mudler/luet/pkg/package"
+)
 
 type Compiler interface {
 	Compile(CompilationSpec) (Artifact, error)
@@ -36,9 +38,30 @@ type CompilerBackend interface {
 	BuildImage(CompilerBackendOptions) error
 	ExportImage(CompilerBackendOptions) error
 	RemoveImage(CompilerBackendOptions) error
+	Changes(fromImage, toImage string) ([]ArtifactLayer, error)
 	ImageDefinitionToTar(CompilerBackendOptions) error
 }
 
+type Artifact interface {
+	GetPath() string
+	SetPath(string)
+}
+
+type ArtifactNode struct {
+	Name string `json:"Name"`
+	Size int    `json:"Size"`
+}
+type ArtifactDiffs struct {
+	Additions []ArtifactNode `json:"Adds"`
+	Deletions []ArtifactNode `json:"Dels"`
+	Changes   []ArtifactNode `json:"Mods"`
+}
+type ArtifactLayer struct {
+	FromImage string        `json:"Image1"`
+	ToImage   string        `json:"Image2"`
+	Diffs     ArtifactDiffs `json:"Diff"`
+}
+
 // CompilationSpec represent a compilation specification derived from a package
 type CompilationSpec interface {
 	RenderBuildImage() (string, error)