Perform app building via docker image

builders/dotnet.go

@@ -63,10 +63,6 @@ indent() {
   sed -u "s/^/       /"
 }
 
-puts-header() {
-  echo "=====> $*"
-}
-
 puts-step() {
   echo "-----> $*"
 }
@@ -103,11 +99,8 @@ hook-package() {
 
   puts-step "Creating package at lambda.zip"
   zip -q -r lambda.zip ./*
-  mv lambda.zip /tmp/task/lambda.zip
-  rm -rf lambda.zip
 }
 
-cp -a /tmp/task/. /var/task
 hook-pre-compile
 install-dotnet
 hook-post-compile

builders/go.go

@@ -69,10 +69,6 @@ indent() {
   sed -u "s/^/       /"
 }
 
-puts-header() {
-  echo "=====> $*"
-}
-
 puts-step() {
   echo "-----> $*"
 }
@@ -117,11 +113,11 @@ hook-package() {
 
   puts-step "Creating package at lambda.zip"
   zip -q -r lambda.zip bootstrap
-  mv lambda.zip /tmp/task/lambda.zip
-  rm -rf lambda.zip
+  mv lambda.zip /var/task/lambda.zip
 }
 
-cp -a /tmp/task/. /go/src/handler
+cp -a /var/task/. /go/src/handler
+cd /go/src/handler
 hook-pre-compile
 install-gomod
 hook-post-compile

builders/main.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 
 	"lambda-builder/io"
 
@@ -31,7 +32,7 @@ type Config struct {
 	Builder           string
 	BuilderBuildImage string
 	BuilderRunImage   string
-	GenerateImage     bool
+	GenerateRunImage  bool
 	Handler           string
 	HandlerMap        map[string]string
 	Identifier        string
@@ -100,7 +101,7 @@ func executeBuilder(script string, config Config) error {
 		}
 	}
 
-	if config.GenerateImage {
+	if config.GenerateRunImage {
 		fmt.Printf("=====> Building image\n")
 		fmt.Printf("       Generating temporary Dockerfile\n")
 
@@ -113,12 +114,12 @@ func executeBuilder(script string, config Config) error {
 			return fmt.Errorf("error generating temporary Dockerfile: %w", err)
 		}
 
-		if err := generateDockerfile(handler, config, dockerfilePath); err != nil {
+		if err := generateRunDockerfile(handler, config, dockerfilePath); err != nil {
 			return err
 		}
 
 		fmt.Printf("       Executing build of %s\n", config.GetImageTag())
-		if err := buildDockerImage(taskHostBuildDir, config, dockerfilePath); err != nil {
+		if err := buildDockerImage(taskHostBuildDir, config, "run", dockerfilePath); err != nil {
 			return err
 		}
 	}
@@ -127,20 +128,109 @@ func executeBuilder(script string, config Config) error {
 }
 
 func executeBuildContainer(script string, config Config) error {
+	fmt.Printf("       Generating temporary build script\n")
+	scriptPath, err := os.Create(filepath.Join(config.WorkingDirectory, ".lambda-builder"))
+	defer func() {
+		os.Remove(scriptPath.Name())
+	}()
+
+	if err != nil {
+		return fmt.Errorf("error generating temporary build script: %w", err)
+	}
+
+	if _, err := scriptPath.WriteString(strings.TrimSpace(script)); err != nil {
+		return err
+	}
+
+	fmt.Printf("       Generating temporary Dockerfile\n")
+	dockerfilePath, err := ioutil.TempFile("", "lambda-builder")
+	defer func() {
+		os.Remove(dockerfilePath.Name())
+	}()
+
+	if err != nil {
+		return fmt.Errorf("error generating temporary Dockerfile: %w", err)
+	}
+
+	if err := generateBuildDockerfile(config, dockerfilePath, scriptPath); err != nil {
+		return err
+	}
+
+	fmt.Printf("       Executing build of %s\n", config.GetImageTag())
+	if err := buildDockerImage(config.WorkingDirectory, config, "build", dockerfilePath); err != nil {
+		return err
+	}
+
+	defer func() {
+		buildImageTag := fmt.Sprintf("%s-build", config.GetImageTag())
+		fmt.Printf("       Removing build image: %s", buildImageTag)
+		args := []string{
+			"image",
+			"rm",
+			"--force",
+			buildImageTag,
+		}
+		cmd := execute.ExecTask{
+			Args:        args,
+			Command:     "docker",
+			Cwd:         config.WorkingDirectory,
+			StreamStdio: !config.RunQuiet,
+		}
+
+		if _, err := cmd.Execute(); err != nil {
+			fmt.Printf("       Error cleaning up build image: %s", err.Error())
+		}
+	}()
+
+	extractLambdaFromBuildImage(config)
+
+	return nil
+}
+
+func generateBuildDockerfile(config Config, dockerfilePath *os.File, scriptPath *os.File) error {
+	tpl, err := template.New("t1").Parse(`
+FROM {{ .build_image }}
+LABEL com.dokku.lambda-builder/builder={{ .builder_name }}
+ENV LAMBDA_BUILD_ZIP=1
+WORKDIR /var/task
+COPY . /var/task
+{{range .env}}
+ENV {{.}}
+{{end}}
+RUN mv {{ .build_script_name }} /usr/local/bin/build-lambda && \
+	chmod +x /usr/local/bin/build-lambda && \
+	head -n1 /usr/local/bin/build-lambda && \
+	/usr/local/bin/build-lambda
+`)
+	if err != nil {
+		return fmt.Errorf("error generating template: %s", err)
+	}
+
+	data := map[string]interface{}{
+		"build_script_name": filepath.Base(scriptPath.Name()),
+		"env":               config.BuildEnv,
+		"builder":           config.Builder,
+		"build_image":       config.BuilderBuildImage,
+	}
+
+	if err := tpl.Execute(dockerfilePath, data); err != nil {
+		return fmt.Errorf("error writing Dockerfile: %s", err)
+	}
+
+	return nil
+}
+
+func extractLambdaFromBuildImage(config Config) error {
 	args := []string{
 		"container",
 		"run",
 		"--rm",
-		"--env", "LAMBDA_BUILD_ZIP=1",
-		"--label", "com.dokku.lambda-builder/executor=true",
-		"--name", fmt.Sprintf("lambda-builder-executor-%s", config.Identifier),
+		"--label", "com.dokku.lambda-builder/extractor=true",
+		"--name", fmt.Sprintf("lambda-builder-extractor-%s", config.Identifier),
 		"--volume", fmt.Sprintf("%s:/tmp/task", config.WorkingDirectory),
 	}
 
-	for _, envPair := range config.BuildEnv {
-		args = append(args, "--env", envPair)
-	}
-	args = append(args, config.BuilderBuildImage, "/bin/bash", "-c", script)
+	args = append(args, fmt.Sprintf("%s-build", config.GetImageTag()), "/bin/bash", "-c", "mv /var/task/lambda.zip /tmp/task/lambda.zip")
 
 	cmd := execute.ExecTask{
 		Args:        args,
@@ -161,7 +251,7 @@ func executeBuildContainer(script string, config Config) error {
 	return nil
 }
 
-func generateDockerfile(cmd string, config Config, dockerfilePath *os.File) error {
+func generateRunDockerfile(cmd string, config Config, dockerfilePath *os.File) error {
 	tpl, err := template.New("t1").Parse(`
 FROM {{ .run_image }}
 {{ if ne .port "-1" }}
@@ -194,17 +284,24 @@ COPY . /var/task
 	return nil
 }
 
-func buildDockerImage(directory string, config Config, dockerfilePath *os.File) error {
+func buildDockerImage(directory string, config Config, phase string, dockerfilePath *os.File) error {
+	imageTag := config.GetImageTag()
+	if phase == "build" {
+		imageTag = fmt.Sprintf("%s-build", config.GetImageTag())
+	}
+
 	args := []string{
 		"image",
 		"build",
 		"--file", dockerfilePath.Name(),
 		"--progress", "plain",
-		"--tag", config.GetImageTag(),
+		"--tag", imageTag,
 	}
 
-	for _, label := range config.ImageLabels {
-		args = append(args, "--label", label)
+	if phase == "run" {
+		for _, label := range config.ImageLabels {
+			args = append(args, "--label", label)
+		}
 	}
 
 	args = append(args, directory)

builders/nodejs.go

@@ -66,10 +66,6 @@ indent() {
   sed -u "s/^/       /"
 }
 
-puts-header() {
-  echo "=====> $*"
-}
-
 puts-step() {
   echo "-----> $*"
 }
@@ -106,11 +102,8 @@ hook-package() {
 
   puts-step "Creating package at lambda.zip"
   zip -q -r lambda.zip ./*
-  mv lambda.zip /tmp/task/lambda.zip
-  rm -rf lambda.zip
 }
 
-cp -a /tmp/task/. /var/task
 hook-pre-compile
 install-npm
 hook-post-compile

builders/python.go

@@ -97,10 +97,6 @@ indent() {
   sed -u "s/^/       /"
 }
 
-puts-header() {
-  echo "=====> $*"
-}
-
 puts-step() {
   echo "-----> $*"
 }
@@ -181,11 +177,8 @@ hook-package() {
 
   puts-step "Creating package at lambda.zip"
   zip -q -r lambda.zip ./*
-  mv lambda.zip /tmp/task/lambda.zip
-  rm -rf lambda.zip
 }
 
-cp -a /tmp/task/. /var/task
 hook-pre-compile
 
 if [[ -f "requirements.txt" ]]; then

builders/ruby.go

@@ -66,10 +66,6 @@ indent() {
   sed -u "s/^/       /"
 }
 
-puts-header() {
-  echo "=====> $*"
-}
-
 puts-step() {
   echo "-----> $*"
 }
@@ -107,11 +103,8 @@ hook-package() {
 
   puts-step "Creating package at lambda.zip"
   zip -q -r lambda.zip ./*
-  mv lambda.zip /tmp/task/lambda.zip
-  rm -rf lambda.zip
 }
 
-cp -a /tmp/task/. /var/task
 hook-pre-compile
 install-bundler
 hook-post-compile

commands/build.go

@@ -22,7 +22,7 @@ type BuildCommand struct {
 	buildEnv         []string
 	builder          string
 	buildImage       string
-	generateImage    bool
+	generateRunImage bool
 	handler          string
 	imageEnv         []string
 	imageTag         string
@@ -73,7 +73,7 @@ func (c *BuildCommand) FlagSet() *flag.FlagSet {
 	}
 
 	f := c.Meta.FlagSet(c.Name(), command.FlagSetClient)
-	f.BoolVar(&c.generateImage, "generate-image", false, "build a docker image")
+	f.BoolVar(&c.generateRunImage, "generate-image", false, "build a docker image")
 	f.BoolVar(&c.quiet, "quiet", false, "run builder in quiet mode")
 	f.BoolVar(&c.writeProcfile, "write-procfile", false, "writes a Procfile if a handler is specified or detected")
 	f.IntVar(&c.port, "port", -1, "set the default port for the lambda to listen on")
@@ -149,7 +149,7 @@ func (c *BuildCommand) Run(args []string) int {
 		Builder:           c.builder,
 		BuilderBuildImage: c.buildImage,
 		BuilderRunImage:   c.runImage,
-		GenerateImage:     c.generateImage,
+		GenerateRunImage:  c.generateRunImage,
 		Identifier:        identifier,
 		ImageEnv:          c.imageEnv,
 		ImageLabels:       c.labels,