Merge pull request #200 from ktock/imagemounter-r

Allow fetching unmodified container images to browser and running them

Dockerfile

@@ -16,6 +16,7 @@ ARG LINUX_LOGLEVEL=7
 ARG INIT_DEBUG=true
 ARG VM_MEMORY_SIZE_MB=128
 ARG NO_VMTOUCH=
+ARG EXTERNAL_BUNDLE=
 
 ARG OUTPUT_NAME=out.wasm # for wasi
 ARG JS_OUTPUT_NAME=out # for emscripten; must not include "."
@@ -43,6 +44,7 @@ ARG TARGETPLATFORM
 ARG INIT_DEBUG
 ARG OPTIMIZATION_MODE
 ARG NO_VMTOUCH
+ARG EXTERNAL_BUNDLE
 COPY --link --from=assets / /work
 WORKDIR /work
 RUN --mount=type=cache,target=/root/.cache/go-build \
@@ -60,12 +62,16 @@ RUN mkdir -p /out/oci/rootfs /out/oci/bundle && \
     NO_VMTOUCH_F=false && \
     if test "${OPTIMIZATION_MODE}" = "native" ; then NO_VMTOUCH_F=true ; fi && \
     if test "${NO_VMTOUCH}" != "" ; then NO_VMTOUCH_F="${NO_VMTOUCH}" ; fi && \
-    create-spec --debug=${INIT_DEBUG} --debug-init=${IS_WIZER} --no-vmtouch=${NO_VMTOUCH_F} \
+    EXTERNAL_BUNDLE_F=false && \
+    if test "${EXTERNAL_BUNDLE}" = "true" ; then EXTERNAL_BUNDLE_F=true ; fi && \
+    create-spec --debug=${INIT_DEBUG} --debug-init=${IS_WIZER} --no-vmtouch=${NO_VMTOUCH_F} --external-bundle=${EXTERNAL_BUNDLE_F} \
                 --image-config-path=/oci/image.json \
                 --runtime-config-path=/oci/spec.json \
                 --rootfs-path=/oci/rootfs \
-                /oci "${TARGETPLATFORM}" /out/oci/rootfs && \
-    mv image.json spec.json /out/oci/ && mv initconfig.json /out/oci/
+                /oci "${TARGETPLATFORM}" /out/oci/rootfs
+RUN if test -f image.json; then mv image.json /out/oci/ ; fi && \
+    if test -f spec.json; then mv spec.json /out/oci/ ; fi
+RUN mv initconfig.json /out/oci/
 
 FROM ubuntu:22.04 AS gcc-riscv64-linux-gnu-base
 RUN apt-get update && apt-get install -y gcc-riscv64-linux-gnu libc-dev-riscv64-cross git make

Dockerfile.test

@@ -26,6 +26,11 @@ COPY ./tests/c2w-net-proxy-test /c2w-net-proxy-test
 WORKDIR /c2w-net-proxy-test
 RUN go build -o /out/c2w-net-proxy-test main.go
 
+FROM golang:1.21 AS imagemounter-test-dev
+COPY ./tests/imagemounter-test /imagemounter-test
+WORKDIR /imagemounter-test
+RUN go build -o /out/imagemounter-test main.go
+
 FROM ubuntu:22.04
 ARG BUILDX_VERSION
 ARG DOCKER_VERSION
@@ -70,6 +75,7 @@ RUN wget https://github.com/WasmEdge/WasmEdge/releases/download/${WASMEDGE_VERSI
 COPY --from=wazero-test-dev /out/wazero-test /usr/local/bin/
 COPY --from=httphello-dev /out/httphello /usr/local/bin/
 COPY --from=c2w-net-proxy-test-dev /out/c2w-net-proxy-test /usr/local/bin/
+COPY --from=imagemounter-test-dev /out/imagemounter-test /usr/local/bin/
 
 # install golang
 RUN wget https://go.dev/dl/go${GOLANG_VERSION}.linux-amd64.tar.gz
@@ -83,6 +89,7 @@ WORKDIR /test/
 RUN go build -o /usr/local/bin/ ./cmd/c2w
 RUN go build -o /usr/local/bin/ ./cmd/c2w-net
 RUN cd extras/c2w-net-proxy/ ; GOOS=wasip1 GOARCH=wasm go build -o /opt/c2w-net-proxy.wasm .
+RUN cd extras/imagemounter/ ; GOOS=wasip1 GOARCH=wasm go build -o /opt/imagemounter.wasm .
 
 ENTRYPOINT ["dockerd-entrypoint.sh"]
 CMD []

Makefile

@@ -21,6 +21,9 @@ c2w-net:
 c2w-net-proxy.wasm:
 	cd extras/c2w-net-proxy/ ; GOOS=wasip1 GOARCH=wasm go build -o $(PREFIX)/c2w-net-proxy.wasm .
 
+imagemounter.wasm:
+	cd extras/imagemounter ; GOOS=wasip1 GOARCH=wasm go build -o $(PREFIX)/imagemounter.wasm .
+
 install:
 	install -D -m 755 $(PREFIX)/c2w $(CMD_DESTDIR)/bin
 	install -D -m 755 $(PREFIX)/c2w-net $(CMD_DESTDIR)/bin

README.md

@@ -310,6 +310,7 @@ Re-compilation (and possibe re-implementation) of the application is needed.
 
 - [`./examples/`](./examples): Examples (python, php, on-browser, networking, etc.)
 - `vscode-container-wasm`: VSCode extension for running containers on VSCode on browser (e.g. `github.dev`), leveraging container2wasm: https://github.com/ktock/vscode-container-wasm
+- [`./extras/imagemounter`]: A helper tool for enabling to distributing and running container images on browser without pre-conversion of the images.
 
 ## Acknowledgement
 

cmd/c2w/main.go

@@ -66,6 +66,10 @@ func main() {
 			Name:  "legacy",
 			Usage: "Use \"docker build\" instead of buildx (no support for assets flag)",
 		},
+		cli.BoolFlag{
+			Name:  "external-bundle",
+			Usage: "Do not embed container image to the Wasm image but mount it during runtime",
+		},
 	}, flags...)
 	app.Action = rootAction
 	if err := app.Run(os.Args); err != nil {
@@ -80,9 +84,22 @@ func rootAction(clicontext *cli.Context) error {
 		fmt.Printf("\n")
 		return nil
 	}
-	srcImgName := clicontext.Args().First()
-	if srcImgName == "" {
-		return fmt.Errorf("specify image name")
+	arg1 := clicontext.Args().First()
+	if arg1 == "" {
+		if clicontext.Bool("external-bundle") {
+			return fmt.Errorf("specify output image name")
+		} else {
+			return fmt.Errorf("specify image name")
+		}
+	}
+	var outputPath string
+	if clicontext.Bool("external-bundle") {
+		outputPath = arg1
+		if clicontext.Args().Get(1) != "" {
+			return fmt.Errorf("command receives only 1 arg (output image path) with external-bundle")
+		}
+	} else {
+		outputPath = clicontext.Args().Get(1)
 	}
 	builderPath, err := exec.LookPath(clicontext.String("builder"))
 	if err != nil {
@@ -100,8 +117,8 @@ func rootAction(clicontext *cli.Context) error {
 	if clicontext.Bool("to-js") {
 		destFile = ""
 	}
-	if o := clicontext.Args().Get(1); o != "" {
-		d, f := filepath.Split(o)
+	if outputPath != "" {
+		d, f := filepath.Split(outputPath)
 		destDir, err = filepath.Abs(d)
 		if err != nil {
 			return err
@@ -113,28 +130,34 @@ func rootAction(clicontext *cli.Context) error {
 	if clicontext.Bool("to-js") && destFile != "" {
 		return fmt.Errorf("output destination must be a slash-terminated directory path when using \"to-js\" option")
 	}
-	if legacy {
-		return buildWithLegacyBuilder(builderPath, srcImgName, destDir, destFile, clicontext)
+	if a := clicontext.String("assets"); a != "" && legacy {
+		return fmt.Errorf("\"assets\" unsupported on docker build as of now; install docker buildx instead")
 	}
 
-	return build(builderPath, srcImgName, destDir, destFile, clicontext)
-}
-
-func build(builderPath string, srcImgName string, destDir, destFile string, clicontext *cli.Context) error {
+	srcImgName := arg1
 	tmpdir, err := os.MkdirTemp("", "container2wasm")
 	if err != nil {
 		return err
 	}
 	defer os.RemoveAll(tmpdir)
-
 	srcImgPath := filepath.Join(tmpdir, "img")
 	if err := os.Mkdir(srcImgPath, 0755); err != nil {
 		return err
 	}
-	if err := prepareSourceImg(builderPath, srcImgName, srcImgPath, clicontext.String("target-arch")); err != nil {
-		return fmt.Errorf("failed to prepare image: %w", err)
+	if !clicontext.Bool("external-bundle") {
+		if err := prepareSourceImg(builderPath, srcImgName, srcImgPath, clicontext.String("target-arch")); err != nil {
+			return fmt.Errorf("failed to prepare image: %w", err)
+		}
+	}
+
+	if legacy {
+		return buildWithLegacyBuilder(builderPath, srcImgPath, destDir, destFile, clicontext)
 	}
 
+	return build(builderPath, srcImgPath, destDir, destFile, clicontext)
+}
+
+func build(builderPath string, srcImgPath string, destDir, destFile string, clicontext *cli.Context) error {
 	buildxArgs := []string{
 		"buildx", "build", "--progress=plain",
 		"--build-arg", fmt.Sprintf("TARGETARCH=%s", clicontext.String("target-arch")),
@@ -145,11 +168,15 @@ func build(builderPath string, srcImgName string, destDir, destFile string, clic
 	if o := clicontext.String("dockerfile"); o != "" {
 		dockerfilePath = o
 	} else {
-		df := filepath.Join(tmpdir, "Dockerfile")
-		if err := os.WriteFile(df, vendor.Dockerfile, 0600); err != nil {
+		f, err := os.CreateTemp("", "container2wasm")
+		if err != nil {
+			return err
+		}
+		defer os.Remove(f.Name())
+		if _, err := f.Write(vendor.Dockerfile); err != nil {
 			return err
 		}
-		dockerfilePath = df
+		dockerfilePath = f.Name()
 	}
 	buildxArgs = append(buildxArgs, "-f", dockerfilePath)
 	if o := clicontext.String("assets"); o != "" {
@@ -173,6 +200,9 @@ func build(builderPath string, srcImgName string, destDir, destFile string, clic
 		"--build-arg", fmt.Sprintf("LINUX_LOGLEVEL=%d", linuxLogLevel),
 		"--build-arg", fmt.Sprintf("INIT_DEBUG=%v", initDebug),
 	)
+	if clicontext.Bool("external-bundle") {
+		buildxArgs = append(buildxArgs, "--build-arg", "EXTERNAL_BUNDLE=true")
+	}
 	for _, a := range clicontext.StringSlice("build-arg") {
 		buildxArgs = append(buildxArgs, "--build-arg", a)
 	}
@@ -185,24 +215,7 @@ func build(builderPath string, srcImgName string, destDir, destFile string, clic
 	return cmd.Run()
 }
 
-func buildWithLegacyBuilder(builderPath string, srcImgName, destDir, destFile string, clicontext *cli.Context) error {
-	if o := clicontext.String("assets"); o != "" {
-		return fmt.Errorf("\"assets\" unsupported on docker build as of now; install docker buildx instead")
-	}
-	tmpdir, err := os.MkdirTemp("", "container2wasm")
-	if err != nil {
-		return err
-	}
-	defer os.RemoveAll(tmpdir)
-
-	srcImgPath := filepath.Join(tmpdir, "img")
-	if err := os.Mkdir(srcImgPath, 0755); err != nil {
-		return err
-	}
-	if err := prepareSourceImg(builderPath, srcImgName, srcImgPath, clicontext.String("target-arch")); err != nil {
-		return fmt.Errorf("failed to prepare image: %w", err)
-	}
-
+func buildWithLegacyBuilder(builderPath string, srcImgPath, destDir, destFile string, clicontext *cli.Context) error {
 	buildArgs := []string{
 		"build", "--progress=plain",
 		"--platform=linux/amd64",
@@ -212,11 +225,15 @@ func buildWithLegacyBuilder(builderPath string, srcImgName, destDir, destFile st
 	if o := clicontext.String("dockerfile"); o != "" {
 		dockerfilePath = o
 	} else {
-		df := filepath.Join(tmpdir, "Dockerfile")
-		if err := os.WriteFile(df, vendor.Dockerfile, 0600); err != nil {
+		f, err := os.CreateTemp("", "container2wasm")
+		if err != nil {
 			return err
 		}
-		dockerfilePath = df
+		defer os.Remove(f.Name())
+		if _, err := f.Write(vendor.Dockerfile); err != nil {
+			return err
+		}
+		dockerfilePath = f.Name()
 	}
 	buildArgs = append(buildArgs, "-f", dockerfilePath)
 	if clicontext.Bool("to-js") {
@@ -237,6 +254,9 @@ func buildWithLegacyBuilder(builderPath string, srcImgName, destDir, destFile st
 		"--build-arg", fmt.Sprintf("LINUX_LOGLEVEL=%d", linuxLogLevel),
 		"--build-arg", fmt.Sprintf("INIT_DEBUG=%v", initDebug),
 	)
+	if clicontext.Bool("external-bundle") {
+		buildArgs = append(buildArgs, "--build-arg", "EXTERNAL_BUNDLE=true")
+	}
 	for _, a := range clicontext.StringSlice("build-arg") {
 		buildArgs = append(buildArgs, "--build-arg", a)
 	}