Add fixtures for testing phases 1 and 2 of Dockerfiles

.github/workflows/build-and-deploy.yml

@@ -35,6 +35,10 @@ jobs:
         run: |
           curl -s -L -o pack.tgz ${{ steps.pack-download-url.outputs.result }}
           tar -xvf pack.tgz
+      - name: Set config needed for image extensions
+        run: |
+          ./pack config experimental true
+          ./pack config pull-policy always
       - name: Build
         run: PACK_CMD=./pack make build-linux build-wine
       - uses: azure/docker-login@v1

Makefile

@@ -1,4 +1,4 @@
-PACK_FLAGS?=--pull-policy=never
+PULL_POLICY_NEVER?=--pull-policy=never
 PACK_BUILD_FLAGS?=--trust-builder
 PACK_CMD?=pack
 
@@ -28,55 +28,55 @@ build-linux-builders: build-builder-alpine build-builder-bionic
 
 build-builder-alpine: build-linux-packages build-sample-root
 	@echo "> Building 'alpine' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:alpine --config $(SAMPLES_ROOT)/builders/alpine/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:alpine --config $(SAMPLES_ROOT)/builders/alpine/builder.toml $(PULL_POLICY_NEVER)
 
 build-builder-bionic: build-linux-packages build-sample-root
 	@echo "> Building 'bionic' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:bionic --config $(SAMPLES_ROOT)/builders/bionic/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:bionic --config $(SAMPLES_ROOT)/builders/bionic/builder.toml $(PULL_POLICY_NEVER)
 
 build-linux-buildpacks: build-buildpacks-alpine build-buildpacks-bionic
 
 build-buildpacks-alpine: build-sample-root
 	@echo "> Creating 'hello-moon' app using 'alpine' builder..."
-	$(PACK_CMD) build sample-hello-moon-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-moon-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-processes' app using 'alpine' builder..."
-	$(PACK_CMD) build sample-hello-processes-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-processes $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-processes-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-processes $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-world' app using 'alpine' builder..."
-	$(PACK_CMD) build sample-hello-world-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-world-app:alpine -v --builder cnbs/sample-builder:alpine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'java-maven' app using 'alpine' builder..."
-	$(PACK_CMD) build sample-java-maven-app:alpine -v --builder cnbs/sample-builder:alpine --path apps/java-maven $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-java-maven-app:alpine -v --builder cnbs/sample-builder:alpine --path apps/java-maven $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'kotlin-gradle' app using 'alpine' builder..."
-	$(PACK_CMD) build sample-kotlin-gradle-app:alpine -v --builder cnbs/sample-builder:alpine --path apps/kotlin-gradle $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-kotlin-gradle-app:alpine -v --builder cnbs/sample-builder:alpine --path apps/kotlin-gradle $(PACK_BUILD_FLAGS)
 
 build-buildpacks-bionic: build-sample-root
 	@echo "> Creating 'hello-moon' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-hello-moon-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-moon-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-processes' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-hello-processes-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-processes $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-processes-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-processes $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-world' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-hello-world-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-world-app:bionic -v --builder cnbs/sample-builder:bionic --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'java-maven' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-java-maven-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/java-maven $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-java-maven-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/java-maven $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'kotlin-gradle' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-kotlin-gradle-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/kotlin-gradle $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-kotlin-gradle-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/kotlin-gradle $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'ruby-bundler' app using 'bionic' builder..."
-	$(PACK_CMD) build sample-ruby-bundler-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/ruby-bundler $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-ruby-bundler-app:bionic -v --builder cnbs/sample-builder:bionic --path apps/ruby-bundler $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-linux-packages: build-sample-root
 	@echo "> Creating 'hello-world' buildpack package"
-	$(PACK_CMD) buildpack package cnbs/sample-package:hello-world --config $(SAMPLES_ROOT)/packages/hello-world/package.toml $(PACK_FLAGS)
+	$(PACK_CMD) buildpack package cnbs/sample-package:hello-world --config $(SAMPLES_ROOT)/packages/hello-world/package.toml $(PULL_POLICY_NEVER)
 
 	@echo "> Creating 'hello-universe' buildpack package"
-	$(PACK_CMD) buildpack package cnbs/sample-package:hello-universe --config $(SAMPLES_ROOT)/packages/hello-universe/package.toml $(PACK_FLAGS)
+	$(PACK_CMD) buildpack package cnbs/sample-package:hello-universe --config $(SAMPLES_ROOT)/packages/hello-universe/package.toml $(PULL_POLICY_NEVER)
 
 deploy-linux: deploy-linux-stacks deploy-linux-packages deploy-linux-builders
 
@@ -156,18 +156,18 @@ build-stack-wine:
 
 build-builder-wine: build-sample-root
 	@echo "> Building 'wine' builder..."
-	$(PACK_CMD) create-builder cnbs/sample-builder:wine --config $(SAMPLES_ROOT)/builders/wine/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) create-builder cnbs/sample-builder:wine --config $(SAMPLES_ROOT)/builders/wine/builder.toml $(PULL_POLICY_NEVER)
 
 build-wine-apps: build-sample-root
 	@echo "> Creating 'batch-script' app using 'wine' builder..."
-	$(PACK_CMD) build sample-batch-script-app:wine -v --builder cnbs/sample-builder:wine --path apps/batch-script $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-batch-script-app:wine -v --builder cnbs/sample-builder:wine --path apps/batch-script $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-buildpacks-wine: build-sample-root
 	@echo "> Creating 'hello-moon-windows' app using 'wine' builder..."
-	$(PACK_CMD) build sample-hello-moon-windows-app:wine -v --builder cnbs/sample-builder:wine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon-windows $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-moon-windows-app:wine -v --builder cnbs/sample-builder:wine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon-windows $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-world-windows' app using 'wine' builder..."
-	$(PACK_CMD) build sample-hello-world-windows-app:wine -v --builder cnbs/sample-builder:wine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-world-windows-app:wine -v --builder cnbs/sample-builder:wine --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 deploy-wine: deploy-wine-stacks deploy-wine-builders
 
@@ -233,45 +233,45 @@ build-stack-dotnet-framework-2022:
 
 build-builder-nanoserver-1809: build-windows-packages
 	@echo "> Building 'nanoserver-1809' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:nanoserver-1809 --config $(SAMPLES_ROOT)/builders/nanoserver-1809/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:nanoserver-1809 --config $(SAMPLES_ROOT)/builders/nanoserver-1809/builder.toml $(PULL_POLICY_NEVER)
 
 build-builder-dotnet-framework-1809: build-windows-packages
 	@echo "> Building 'dotnet-framework-1809' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-1809 --config $(SAMPLES_ROOT)/builders/dotnet-framework-1809/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-1809 --config $(SAMPLES_ROOT)/builders/dotnet-framework-1809/builder.toml $(PULL_POLICY_NEVER)
 
 build-builder-dotnet-framework-2004: build-windows-packages
 	@echo "> Building 'dotnet-framework-2004' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-2004 --config $(SAMPLES_ROOT)/builders/dotnet-framework-2004/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-2004 --config $(SAMPLES_ROOT)/builders/dotnet-framework-2004/builder.toml $(PULL_POLICY_NEVER)
 
 build-builder-dotnet-framework-2022: build-windows-packages
 	@echo "> Building 'dotnet-framework-2022' builder..."
-	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-2022 --config $(SAMPLES_ROOT)/builders/dotnet-framework-2022/builder.toml $(PACK_FLAGS)
+	$(PACK_CMD) builder create cnbs/sample-builder:dotnet-framework-2022 --config $(SAMPLES_ROOT)/builders/dotnet-framework-2022/builder.toml $(PULL_POLICY_NEVER)
 
 build-buildpacks-nanoserver-1809: build-sample-root
 	@echo "> Creating 'hello-moon-windows' app using 'nanoserver-1809' builder..."
-	$(PACK_CMD) build sample-hello-moon-windows-app:nanoserver-1809 -v --builder cnbs/sample-builder:nanoserver-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon-windows $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-moon-windows-app:nanoserver-1809 -v --builder cnbs/sample-builder:nanoserver-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows --buildpack $(SAMPLES_ROOT)/buildpacks/hello-moon-windows $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 	@echo "> Creating 'hello-world-windows' app using 'nanoserver-1809' builder..."
-	$(PACK_CMD) build sample-hello-world-windows-app:nanoserver-1809 -v --builder cnbs/sample-builder:nanoserver-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-hello-world-windows-app:nanoserver-1809 -v --builder cnbs/sample-builder:nanoserver-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/hello-world-windows $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-buildpacks-dotnet-framework-1809: build-sample-root
 	@echo "> Creating 'dotnet-framework' app using 'dotnet-framework-1809' builder..."
-	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-1809 -v --builder cnbs/sample-builder:dotnet-framework-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-1809 -v --builder cnbs/sample-builder:dotnet-framework-1809 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-buildpacks-dotnet-framework-2004: build-sample-root
 	@echo "> Creating 'dotnet-framework' app using 'dotnet-framework-2004' builder..."
-	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-2004 -v --builder cnbs/sample-builder:dotnet-framework-2004 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-2004 -v --builder cnbs/sample-builder:dotnet-framework-2004 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-buildpacks-dotnet-framework-2022: build-sample-root
 	@echo "> Creating 'dotnet-framework' app using 'dotnet-framework-2022' builder..."
-	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-2022 -v --builder cnbs/sample-builder:dotnet-framework-2022 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PACK_FLAGS) $(PACK_BUILD_FLAGS)
+	$(PACK_CMD) build sample-dotnet-framework-app:dotnet-framework-2022 -v --builder cnbs/sample-builder:dotnet-framework-2022 --buildpack $(SAMPLES_ROOT)/buildpacks/dotnet-framework --path apps/aspnet $(PULL_POLICY_NEVER) $(PACK_BUILD_FLAGS)
 
 build-windows-packages: build-sample-root
 	@echo "> Creating 'hello-world-windows' buildpack package"
-	$(PACK_CMD) buildpack package cnbs/sample-package:hello-world-windows --config $(SAMPLES_ROOT)/packages/hello-world-windows/package.toml $(PACK_FLAGS)
+	$(PACK_CMD) buildpack package cnbs/sample-package:hello-world-windows --config $(SAMPLES_ROOT)/packages/hello-world-windows/package.toml $(PULL_POLICY_NEVER)
 
 	@echo "> Creating 'hello-universe-windows' buildpack package"
-	$(PACK_CMD) buildpack package cnbs/sample-package:hello-universe-windows --config $(SAMPLES_ROOT)/packages/hello-universe-windows/package.toml $(PACK_FLAGS)
+	$(PACK_CMD) buildpack package cnbs/sample-package:hello-universe-windows --config $(SAMPLES_ROOT)/packages/hello-universe-windows/package.toml $(PULL_POLICY_NEVER)
 
 deploy-windows-packages:
 	@echo "> Deploying windows packages..."

builders/alpine/builder.toml

@@ -12,7 +12,28 @@ uri = "../../buildpacks/kotlin-gradle"
 [[buildpacks]]
 uri = "docker://cnbs/sample-package:hello-universe"
 
-# Order used for detection
+[[buildpacks]]
+id = "samples/hello-extensions"
+version = "0.0.1"
+uri = "../../buildpacks/hello-extensions"
+
+# Extensions to include in builder
+[[extensions]]
+id = "samples/tree"
+version = "0.0.1"
+uri = "../../extensions/tree"
+
+[[extensions]]
+id = "samples/curl"
+version = "0.0.1"
+uri = "../../extensions/curl"
+
+# Order used for detection (buildpacks)
+[[order]]
+[[order.group]]
+id = "samples/hello-extensions"
+version = "0.0.1"
+
 [[order]]
 [[order.group]]
 id = "samples/java-maven"
@@ -28,6 +49,16 @@ version = "0.0.1"
 id = "samples/hello-universe"
 version = "0.0.1"
 
+# Order used for detection (extensions)
+[[order-extensions]]
+[[order-extensions.group]]
+id = "samples/tree"
+version = "0.0.1"
+
+[[order-extensions.group]]
+id = "samples/curl"
+version = "0.0.1"
+
 # Stack that will be used by the builder
 [stack]
 id = "io.buildpacks.samples.stacks.alpine"

buildpacks/hello-extensions/bin/build

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+echo "---> Hello Extensions Buildpack"
+
+tree --version
+
+layers_dir=$1
+
+cat >> "${layers_dir}/launch.toml" <<EOL
+[[processes]]
+type = "curl"
+command = ["curl"]
+args = ["--version"]
+default = true
+EOL

buildpacks/hello-extensions/bin/detect

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# 1. GET ARGS
+plan_path=$2
+
+# 2. DECLARE DEPENDENCIES (OPTIONAL)
+cat >> "${plan_path}" <<EOL
+# Uncomment first
+#[[requires]]
+#name = "tree"
+
+# Uncomment second
+#[[requires]]
+#name = "curl"
+EOL

buildpacks/hello-extensions/buildpack.toml

@@ -0,0 +1,14 @@
+# Buildpack API version
+api = "0.9"
+
+# Buildpack ID and metadata
+[buildpack]
+id = "samples/hello-extensions"
+version = "0.0.1"
+name = "Hello Extensions Buildpack"
+homepage = "https://github.com/buildpacks/samples/tree/main/buildpacks/hello-extensions"
+description = "A simple buildpack that requires curl."
+
+# Stacks that the buildpack will work with
+[[stacks]]
+id = "*"

extensions/curl/bin/detect

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# 1. GET ARGS
+plan_path=$CNB_BUILD_PLAN_PATH
+
+# 2. DECLARE DEPENDENCIES (OPTIONAL)
+cat >> "${plan_path}" <<EOL
+# Extension provides this dependency
+[[provides]]
+name = "curl"
+EOL

extensions/curl/bin/generate

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# 1. GET ARGS
+output_dir=$CNB_OUTPUT_DIR
+
+# 2. GENERATE run.Dockerfile
+cat >> "${output_dir}/run.Dockerfile" <<EOL
+FROM run-image-curl
+EOL

extensions/curl/extension.toml

@@ -0,0 +1,10 @@
+# Buildpack API version
+api = "0.9"
+
+# Extension ID and metadata
+[extension]
+id = "samples/curl"
+version = "0.0.1"
+name = "Curl Extension"
+homepage = "https://github.com/buildpacks/samples/tree/main/extensions/curl"
+description = "A simple extension that switches the runtime base image to `curlimages/curl:latest`"

extensions/tree/bin/detect

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# 1. GET ARGS
+plan_path=$CNB_BUILD_PLAN_PATH
+
+# 2. DECLARE DEPENDENCIES (OPTIONAL)
+cat >> "${plan_path}" <<EOL
+# Extension provides this dependency
+[[provides]]
+name = "tree"
+EOL

extensions/tree/bin/generate

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+# 1. GET ARGS
+output_dir=$CNB_OUTPUT_DIR
+
+# 2. GENERATE build.Dockerfile
+cat >> "${output_dir}/build.Dockerfile" <<EOL
+ARG base_image
+FROM \${base_image}
+
+USER root
+RUN apk update update && apk add tree
+EOL

extensions/tree/extension.toml

@@ -0,0 +1,10 @@
+# Buildpack API version
+api = "0.9"
+
+# Extension ID and metadata
+[extension]
+id = "samples/tree"
+version = "0.0.1"
+name = "Tree Extension"
+homepage = "https://github.com/buildpacks/samples/tree/main/extensions/tree"
+description = "A simple extension that installs tree at build time"

stacks/alpine/run/curl.Dockerfile

@@ -0,0 +1,20 @@
+FROM curlimages/curl
+
+ARG cnb_uid=1000
+ARG cnb_gid=1001
+
+# Create user and group
+USER root
+RUN addgroup -g ${cnb_gid} cnb && \
+  adduser -u ${cnb_uid} -G cnb -s /bin/bash -D cnb
+
+# Set user and group (as declared in base image)
+USER ${CNB_USER_ID}:${CNB_GROUP_ID}
+
+# Set required CNB information
+ENV CNB_USER_ID=${cnb_uid}
+ENV CNB_GROUP_ID=${cnb_gid}
+
+# Set required CNB information
+LABEL io.buildpacks.stack.id=io.buildpacks.samples.stacks.alpine
+