feat(staged-dockerfile): refactored container backend dockerfile builder

* Unified interface of instructions.
* No switch-case by instruction type, use polymorphism instead.
* Introduced BuildContext to keep unpacked context tar between executing multiple instructions.
* Renaming of primitives and some packages.

Signed-off-by: Timofey Kirillov <timofey.kirillov@flant.com>

pkg/build/build_phase.go

@@ -21,6 +21,7 @@ import (
 	"github.com/werf/werf/pkg/build/image"
 	"github.com/werf/werf/pkg/build/stage"
 	"github.com/werf/werf/pkg/container_backend"
+	backend_instruction "github.com/werf/werf/pkg/container_backend/instruction"
 	"github.com/werf/werf/pkg/docker_registry"
 	"github.com/werf/werf/pkg/git_repo"
 	imagePkg "github.com/werf/werf/pkg/image"
@@ -676,8 +677,7 @@ func (phase *BuildPhase) prepareStageInstructions(ctx context.Context, img *imag
 			return stageImage.Builder.DockerfileBuilder().Cleanup(ctx)
 		})
 	} else {
-		stageImage.Builder.DockerfileStageBuilder().AppendPostCommands(&container_backend.InstructionLabel{Labels: serviceLabels})
-		// staged dockerfile
+		stageImage.Builder.DockerfileStageBuilder().AppendPostInstruction(backend_instruction.NewLabel(serviceLabels))
 	}
 
 	err := stg.PrepareImage(ctx, phase.Conveyor, phase.Conveyor.ContainerBackend, phase.StagesIterator.GetPrevBuiltImage(img, stg), stageImage)

pkg/build/image/dockerfile.go

@@ -12,9 +12,9 @@ import (
 
 	"github.com/werf/logboek"
 	"github.com/werf/werf/pkg/build/stage"
-	"github.com/werf/werf/pkg/build/stage/dockerfile_instruction"
+	stage_instruction "github.com/werf/werf/pkg/build/stage/instruction"
 	"github.com/werf/werf/pkg/config"
-	"github.com/werf/werf/pkg/container_backend"
+	backend_instruction "github.com/werf/werf/pkg/container_backend/instruction"
 	"github.com/werf/werf/pkg/dockerfile"
 	"github.com/werf/werf/pkg/path_matcher"
 	"github.com/werf/werf/pkg/util"
@@ -82,7 +82,7 @@ func mapDockerfileToImagesSets(ctx context.Context, cfg *dockerfile.Dockerfile,
 			return nil, fmt.Errorf("unable to create image %q: %w", "test", err)
 		}
 
-		img.stages = append(img.stages, dockerfile_instruction.NewRun(&container_backend.InstructionRun{Command: []string{"ls", "/"}}, nil, false, &stage.BaseStageOptions{
+		img.stages = append(img.stages, stage_instruction.NewRun(backend_instruction.NewRun([]string{"ls", "/"}), nil, false, &stage.BaseStageOptions{
 			ImageName:        img.Name,
 			ImageTmpDir:      img.TmpDir,
 			ContainerWerfDir: img.ContainerWerfDir,

pkg/build/stage/dockerfile_instruction/base.go → pkg/build/stage/instruction/base.go

@@ -1,4 +1,4 @@
-package dockerfile_instruction
+package instruction
 
 import (
 	"github.com/werf/werf/pkg/build/stage"

pkg/build/stage/dockerfile_instruction/dockerfile_instruction.go → pkg/build/stage/instruction/instruction.go

@@ -1,4 +1,4 @@
-package dockerfile_instruction
+package instruction
 
 import "github.com/werf/werf/pkg/build/stage"
 

pkg/build/stage/dockerfile_instruction/run.go → pkg/build/stage/instruction/run.go

@@ -1,31 +1,32 @@
-package dockerfile_instruction
+package instruction
 
 import (
 	"context"
 
 	"github.com/werf/werf/pkg/build/stage"
 	"github.com/werf/werf/pkg/config"
 	"github.com/werf/werf/pkg/container_backend"
+	backend_instruction "github.com/werf/werf/pkg/container_backend/instruction"
 	"github.com/werf/werf/pkg/util"
 )
 
 type Run struct {
 	*Base
-	instruction *container_backend.InstructionRun
+	instruction *backend_instruction.Run
 }
 
-func NewRun(instruction *container_backend.InstructionRun, dependencies []*config.Dependency, hasPrevStage bool, opts *stage.BaseStageOptions) *Run {
+func NewRun(i *backend_instruction.Run, dependencies []*config.Dependency, hasPrevStage bool, opts *stage.BaseStageOptions) *Run {
 	return &Run{
-		Base:        NewBase("RUN", dependencies, hasPrevStage, opts),
-		instruction: instruction,
+		Base:        NewBase(InstructionRun, dependencies, hasPrevStage, opts),
+		instruction: i,
 	}
 }
 
 func (stage *Run) GetDependencies(ctx context.Context, c stage.Conveyor, cb container_backend.ContainerBackend, prevImage, prevBuiltImage *stage.StageImage) (string, error) {
-	return util.Sha256Hash(stage.instruction.Command...), nil
+	return util.Sha256Hash(append([]string{string(InstructionRun)}, stage.instruction.Command...)...), nil
 }
 
 func (stage *Run) PrepareImage(ctx context.Context, c stage.Conveyor, cb container_backend.ContainerBackend, prevBuiltImage, stageImage *stage.StageImage) error {
-	stageImage.Builder.DockerfileStageBuilder().AppendMainCommands(stage.instruction)
+	stageImage.Builder.DockerfileStageBuilder().AppendInstruction(stage.instruction)
 	return nil
 }

pkg/container_backend/build_context/build_context.go

@@ -0,0 +1,54 @@
+package build_context
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/werf/werf/pkg/util"
+)
+
+type BuildContext struct {
+	ContextTarReader io.ReadCloser
+	TmpDir           string
+
+	contextTmpDir string
+}
+
+func NewBuildContext(tmpDir string, contextTarReader io.ReadCloser) *BuildContext {
+	return &BuildContext{TmpDir: tmpDir, ContextTarReader: contextTarReader}
+}
+
+func (c *BuildContext) GetContextDir(ctx context.Context) (string, error) {
+	if c.contextTmpDir != "" {
+		return c.contextTmpDir, nil
+	}
+
+	contextTmpDir, err := ioutil.TempDir(c.TmpDir, "context")
+	if err != nil {
+		return "", fmt.Errorf("unable to create context tmp dir: %w", err)
+	}
+
+	if err := util.ExtractTar(c.ContextTarReader, contextTmpDir, util.ExtractTarOptions{}); err != nil {
+		return "", fmt.Errorf("unable to extract context tar to tmp context dir: %w", err)
+	}
+	if err := c.ContextTarReader.Close(); err != nil {
+		return "", fmt.Errorf("error closing context tar: %w", err)
+	}
+
+	c.contextTmpDir = contextTmpDir
+
+	return c.contextTmpDir, nil
+}
+
+func (c *BuildContext) Terminate() error {
+	if c.contextTmpDir == "" {
+		return nil
+	}
+	if err := os.RemoveAll(c.contextTmpDir); err != nil {
+		return fmt.Errorf("unable to remove dir %q: %w", c.contextTmpDir, err)
+	}
+	return nil
+}

pkg/container_backend/buildah_backend.go

@@ -20,6 +20,7 @@ import (
 	copyrec "github.com/werf/copy-recurse"
 	"github.com/werf/logboek"
 	"github.com/werf/werf/pkg/buildah"
+	"github.com/werf/werf/pkg/container_backend/build_context"
 	"github.com/werf/werf/pkg/image"
 	"github.com/werf/werf/pkg/path_matcher"
 	"github.com/werf/werf/pkg/util"
@@ -422,10 +423,22 @@ func (runtime *BuildahBackend) applyDependenciesImports(ctx context.Context, con
 	return nil
 }
 
-func (runtime *BuildahBackend) BuildDockerfileStage(ctx context.Context, baseImage string, opts BuildDockerfileStageOptions, instructions ...any) (string, error) {
+func (runtime *BuildahBackend) BuildDockerfileStage(ctx context.Context, baseImage string, opts BuildDockerfileStageOptions, instructions ...InstructionInterface) (string, *build_context.BuildContext, error) {
+	buildContext := opts.BuildContext
+	if buildContext == nil {
+		for _, instruction := range instructions {
+			if instruction.UsesBuildContext() {
+				if opts.ContextTarReader == nil {
+					panic(fmt.Sprintf("opts.ContextTarReader needed for %q instruction", instruction.Name()))
+				}
+				buildContext = build_context.NewBuildContext(runtime.TmpDir, opts.ContextTarReader)
+			}
+		}
+	}
+
 	var container *containerDesc
 	if c, err := runtime.createContainers(ctx, []string{baseImage}); err != nil {
-		return "", err
+		return "", nil, err
 	} else {
 		container = c[0]
 	}
@@ -439,7 +452,7 @@ func (runtime *BuildahBackend) BuildDockerfileStage(ctx context.Context, baseIma
 
 	logboek.Context(ctx).Debug().LogF("Mounting build container %s\n", container.Name)
 	if err := runtime.mountContainers(ctx, []*containerDesc{container}); err != nil {
-		return "", fmt.Errorf("unable to mount build container %s: %w", container.Name, err)
+		return "", buildContext, fmt.Errorf("unable to mount build container %s: %w", container.Name, err)
 	}
 	defer func() {
 		logboek.Context(ctx).Debug().LogF("Unmounting build container %s\n", container.Name)
@@ -448,127 +461,11 @@ func (runtime *BuildahBackend) BuildDockerfileStage(ctx context.Context, baseIma
 		}
 	}()
 
-	var contextTmpDir string
-	if opts.ContextTar != nil {
-		var err error
-
-		// TODO(staged-dockerfile): build-context object param
-		contextTmpDir, err = runtime.ExtractContext(opts.ContextTar)
-		if err != nil {
-			return "", fmt.Errorf("error extracting context: %w", err)
-		}
-
-		defer func() {
-			if err := os.RemoveAll(contextTmpDir); err != nil {
-				logboek.Context(ctx).Error().LogF("ERROR: unable to remove temporary context dir %s: %s\n", contextTmpDir, err)
-			}
-		}()
-	}
-
 	logboek.Context(ctx).Debug().LogF("Executing commands for build container %s: %#v\n", container.Name, instructions)
 
-	for _, i := range instructions {
-		switch instruction := i.(type) {
-		case *InstructionLabel:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Labels:     instruction.LabelsAsList(),
-			}); err != nil {
-				return "", fmt.Errorf("error setting labels %v for container %s: %w", instruction.LabelsAsList(), container.Name, err)
-			}
-		case *InstructionExpose:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Expose:     instruction.Ports,
-			}); err != nil {
-				return "", fmt.Errorf("error setting exposed ports %v for container %s: %w", instruction.Ports, container.Name, err)
-			}
-		case *InstructionVolume:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Volumes:    instruction.Volumes,
-			}); err != nil {
-				return "", fmt.Errorf("error setting volumes %v for container %s: %w", instruction.Volumes, container.Name, err)
-			}
-		case *InstructionOnBuild:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				OnBuild:    instruction.Instruction,
-			}); err != nil {
-				return "", fmt.Errorf("error setting onbuild %v for container %s: %w", instruction.Instruction, container.Name, err)
-			}
-		case *InstructionStopSignal:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				StopSignal: instruction.Signal,
-			}); err != nil {
-				return "", fmt.Errorf("error setting stop signal %v for container %s: %w", instruction.Signal, container.Name, err)
-			}
-		case *InstructionShell:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Shell:      instruction.Shell,
-			}); err != nil {
-				return "", fmt.Errorf("error setting shell %v for container %s: %w", instruction.Shell, container.Name, err)
-			}
-		case *InstructionEnv:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Envs:       instruction.Envs,
-			}); err != nil {
-				return "", fmt.Errorf("error setting envs %v for container %s: %w", instruction.Envs, container.Name, err)
-			}
-		case *InstructionRun:
-			if err := runtime.buildah.RunCommand(ctx, container.Name, instruction.Command, buildah.RunCommandOpts{
-				// FIXME(ilya-lesikov): should we suppress or not?
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-			}); err != nil {
-				return "", fmt.Errorf("error running command %v for container %s: %w", instruction.Command, container.Name, err)
-			}
-		case *InstructionCopy:
-			if err := runtime.buildah.Copy(ctx, container.Name, contextTmpDir, instruction.Src, instruction.Dst, buildah.CopyOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				From:       instruction.From,
-			}); err != nil {
-				return "", fmt.Errorf("error copying %v to %s for container %s: %w", instruction.Src, instruction.Dst, container.Name, err)
-			}
-		case *InstructionAdd:
-			if err := runtime.buildah.Add(ctx, container.Name, instruction.Src, instruction.Dst, buildah.AddOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				ContextDir: contextTmpDir,
-			}); err != nil {
-				return "", fmt.Errorf("error adding %v to %s for container %s: %w", instruction.Src, instruction.Dst, container.Name, err)
-			}
-		case *InstructionUser:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				User:       instruction.User,
-			}); err != nil {
-				return "", fmt.Errorf("error setting user %s for container %s: %w", instruction.User, container.Name, err)
-			}
-		case *InstructionWorkdir:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Workdir:    instruction.Workdir,
-			}); err != nil {
-				return "", fmt.Errorf("error setting workdir %s for container %s: %w", instruction.Workdir, container.Name, err)
-			}
-		case *InstructionEntrypoint:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Entrypoint: instruction.Entrypoint,
-			}); err != nil {
-				return "", fmt.Errorf("error setting entrypoint %v for container %s: %w", instruction.Entrypoint, container.Name, err)
-			}
-		case *InstructionCmd:
-			if err := runtime.buildah.Config(ctx, container.Name, buildah.ConfigOpts{
-				CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
-				Cmd:        instruction.Cmd,
-			}); err != nil {
-				return "", fmt.Errorf("error setting cmd %v for container %s: %w", instruction.Cmd, container.Name, err)
-			}
-		default:
-			panic(fmt.Sprintf("invalid command type: %T", i))
+	for _, instruction := range instructions {
+		if err := instruction.Apply(ctx, container.Name, runtime.buildah, runtime.getBuildahCommonOpts(ctx, false), buildContext); err != nil {
+			return "", buildContext, fmt.Errorf("unable to apply instruction %s: %w", instruction.Name(), err)
 		}
 	}
 
@@ -577,10 +474,10 @@ func (runtime *BuildahBackend) BuildDockerfileStage(ctx context.Context, baseIma
 		CommonOpts: runtime.getBuildahCommonOpts(ctx, true),
 	})
 	if err != nil {
-		return "", fmt.Errorf("error committing container %s: %w", container.Name, err)
+		return "", buildContext, fmt.Errorf("error committing container %s: %w", container.Name, err)
 	}
 
-	return imageID, nil
+	return imageID, buildContext, nil
 }
 
 func (runtime *BuildahBackend) BuildStapelStage(ctx context.Context, baseImage string, opts BuildStapelStageOptions) (string, error) {
@@ -728,13 +625,14 @@ func (runtime *BuildahBackend) BuildDockerfile(ctx context.Context, dockerfileCo
 		buildArgs[argParts[0]] = argParts[1]
 	}
 
-	contextTmpDir, err := runtime.ExtractContext(opts.ContextTar)
+	buildContext := build_context.NewBuildContext(runtime.TmpDir, opts.ContextTar)
+	contextTmpDir, err := buildContext.GetContextDir(ctx)
 	if err != nil {
-		return "", fmt.Errorf("error extracting context: %w", err)
+		return "", fmt.Errorf("unable to get context dir: %w", err)
 	}
 	defer func() {
-		if err := os.RemoveAll(contextTmpDir); err != nil {
-			logboek.Context(ctx).Error().LogF("ERROR: unable to remove temporary context dir %s: %s\n", contextTmpDir, err)
+		if err := buildContext.Terminate(); err != nil {
+			logboek.Context(ctx).Error().LogF("ERROR: unable to terminate dockerfile building context: %s\n", err)
 		}
 	}()
 
@@ -876,21 +774,6 @@ func (runtime *BuildahBackend) RemoveHostDirs(ctx context.Context, mountDir stri
 	})
 }
 
-func (runtime *BuildahBackend) ExtractContext(contextTar io.Reader) (string, error) {
-	contextTmpDir, err := ioutil.TempDir(runtime.TmpDir, "context")
-	if err != nil {
-		return "", fmt.Errorf("unable to create context tmp dir: %w", err)
-	}
-
-	if contextTar != nil {
-		if err := util.ExtractTar(contextTar, contextTmpDir, util.ExtractTarOptions{}); err != nil {
-			return "", fmt.Errorf("unable to extract context tar to tmp context dir: %w", err)
-		}
-	}
-
-	return contextTmpDir, nil
-}
-
 func parseVolume(volume string) (string, string, error) {
 	volumeParts := strings.SplitN(volume, ":", 2)
 	if len(volumeParts) != 2 {

pkg/container_backend/docker_server_backend.go

@@ -10,6 +10,7 @@ import (
 	"github.com/google/uuid"
 
 	"github.com/werf/logboek"
+	"github.com/werf/werf/pkg/container_backend/build_context"
 	"github.com/werf/werf/pkg/docker"
 	"github.com/werf/werf/pkg/image"
 	"github.com/werf/werf/pkg/util"
@@ -79,7 +80,7 @@ func (runtime *DockerServerBackend) BuildDockerfile(ctx context.Context, _ []byt
 	return tempID, docker.CliBuild_LiveOutputWithCustomIn(ctx, opts.ContextTar, cliArgs...)
 }
 
-func (runtime *DockerServerBackend) BuildDockerfileStage(ctx context.Context, baseImage string, opts BuildDockerfileStageOptions, instructions ...any) (string, error) {
+func (runtime *DockerServerBackend) BuildDockerfileStage(ctx context.Context, baseImage string, opts BuildDockerfileStageOptions, instructions ...InstructionInterface) (string, *build_context.BuildContext, error) {
 	panic("not implemented")
 }