Add initial "slim" variant support

Ref #48

generate-stackbrew-library.sh

@@ -95,15 +95,17 @@ for version in "${versions[@]}"; do
 		Directory: $version
 	EOE
 
-	if [ "$(git show "$commit:$version/backports/Dockerfile" 2>/dev/null || true)" ]; then
-		echo
-		cat <<-EOE
-			Tags: $version-backports
-			GitFetch: refs/heads/$branch
-			GitCommit: $commit
-			Directory: $version/backports
-		EOE
-	fi
+	for imageVariant in slim backports; do
+		if [ "$(git show "$commit:$version/$imageVariant/Dockerfile" 2>/dev/null || true)" ]; then
+			echo
+			cat <<-EOE
+				Tags: $version-$imageVariant
+				GitFetch: refs/heads/$branch
+				GitCommit: $commit
+				Directory: $version/$imageVariant
+			EOE
+		fi
+	done
 done
 
 dockerfilesBase='https://github.com/tianon/dockerfiles'

slim-excludes

@@ -0,0 +1,10 @@
+#   This file contains the list of files/directories which will be removed for the "slim" image variants.
+#  https://github.com/tianon/docker-brew-debian/issues/48
+# https://wiki.ubuntu.com/ReducingDiskFootprint#Drop_unnecessary_files
+/usr/share/doc/*
+/usr/share/groff/*
+/usr/share/info/*
+/usr/share/linda/*
+/usr/share/lintian/*
+/usr/share/locale/*
+/usr/share/man/*

update.sh

@@ -107,7 +107,7 @@ for version in "${versions[@]}"; do
 	mirror="$(get_part "$dir" mirror '')"
 	script="$(get_part "$dir" script '')"
 
-	args=( -d "$dir" debootstrap )
+	args=( --dir "$dir" --compression 'xz' debootstrap )
 	[ -z "$variant" ] || args+=( --variant="$variant" )
 	[ -z "$components" ] || args+=( --components="$components" )
 	[ -z "$include" ] || args+=( --include="$include" )
@@ -135,6 +135,7 @@ for version in "${versions[@]}"; do
 		echo 'https://github.com/docker/docker/blob/master/contrib/mkimage.sh'
 	} > "$dir/build-command.txt"
 
+	sudo rm -rf "$dir/rootfs"
 	sudo nice ionice -c 3 "$mkimage" "${args[@]}" 2>&1 | tee "$dir/build.log"
 
 	sudo chown -R "$(id -u):$(id -g)" "$dir"
@@ -158,13 +159,97 @@ for version in "${versions[@]}"; do
 			true
 		'
 		docker run --rm "${repo}:${suite}" dpkg-query -f '${Package}\t${Version}\n' -W > "$dir/build.manifest"
+	fi
+
+	if [ "${backports[$suite]}" ]; then
+		mkdir -p "$dir/backports"
+		echo "FROM $origRepo:$suite" > "$dir/backports/Dockerfile"
+		cat >> "$dir/backports/Dockerfile" <<-'EOF'
+			RUN awk '$1 ~ "^deb" { $3 = $3 "-backports"; print; exit }' /etc/apt/sources.list > /etc/apt/sources.list.d/backports.list
+		EOF
+
+		if [ "$repo" ]; then
+			( set -x && docker build -t "${repo}:${suite}-backports" "$dir/backports" )
+		fi
+	fi
+
+	IFS=$'\n'
+	set -o noglob
+	slimExcludes=( $(get_part "$dir" slim-excludes '' | grep -vE '^#|^$') )
+	set +o noglob
+	unset IFS
+	if [ "${#slimExcludes[@]}" -gt 0 ]; then
+		sudo rm -rf "$dir/slim/rootfs"
+		mkdir -p "$dir/slim/rootfs"
+		sudo tar --extract --file "$dir/rootfs.tar.xz" --directory "$dir/slim/rootfs"
+
+		dpkgCfgFile="$dir/slim/rootfs/etc/dpkg/dpkg.cfg.d/docker"
+		sudo mkdir -p "$(dirname "$dpkgCfgFile")"
+		{
+			echo '# This is the "slim" variant of the Debian base image.'
+			echo '# Many files which are normally unnecessary in containers are excluded,'
+			echo '# and this configuration file keeps them that way.'
+		} | sudo tee -a "$dpkgCfgFile"
 
-		if [ "${backports[$suite]}" ]; then
-			mkdir -p "$dir/backports"
-			echo "FROM $origRepo:$suite" > "$dir/backports/Dockerfile"
-			cat >> "$dir/backports/Dockerfile" <<-'EOF'
-				RUN awk '$1 ~ "^deb" { $3 = $3 "-backports"; print; exit }' /etc/apt/sources.list > /etc/apt/sources.list.d/backports.list
-			EOF
+		neverExclude='/usr/share/doc/*/copyright'
+		for slimExclude in "${slimExcludes[@]}"; do
+			{
+				echo
+				echo "# dpkg -S '$slimExclude'"
+				if dpkgOutput="$(sudo chroot "$dir/slim/rootfs" dpkg -S "$slimExclude" 2>&1)"; then
+					echo "$dpkgOutput" | sed 's/: .*//g; s/, /\n/g' | sort -u | xargs
+				else
+					echo "$dpkgOutput"
+				fi | fold -w 76 -s | sed 's/^/#  /'
+				echo "path-exclude $slimExclude"
+			} | sudo tee -a "$dpkgCfgFile"
+			if [[ "$slimExclude" == *'/*' ]]; then
+				if [ -d "$dir/slim/rootfs/$(dirname "$slimExclude")" ]; then
+					# use two passes so that we don't fail trying to remove directories from $neverExclude
+					sudo chroot "$dir/slim/rootfs" \
+						find "$(dirname "$slimExclude")" \
+							-mindepth 1 \
+							-not -path "$neverExclude" \
+							-not -type d \
+							-delete
+					sudo chroot "$dir/slim/rootfs" \
+						find "$(dirname "$slimExclude")" \
+							-mindepth 1 \
+							-empty \
+							-delete
+				fi
+			else
+				sudo chroot "$dir/slim/rootfs" rm -f "$slimExclude"
+			fi
+		done
+		{
+			echo
+			echo '# always include these files, especially for license compliance'
+			echo "path-include $neverExclude"
+		} | sudo tee -a "$dpkgCfgFile"
+
+		sudo tar --numeric-owner --create --auto-compress --file "$dir/slim/rootfs.tar.xz" --directory "$dir/slim/rootfs" --transform='s,^./,,' .
+		sudo rm -rf "$dir/slim/rootfs"
+		cp "$dir/Dockerfile" "$dir/slim/"
+
+		sudo chown -R "$(id -u):$(id -g)" "$dir/slim"
+
+		ls -lh "$dir/rootfs.tar.xz" "$dir/slim/rootfs.tar.xz"
+
+		if [ "$repo" ]; then
+			( set -x && docker build -t "${repo}:${suite}-slim" "$dir/slim" )
+			docker images "${repo}:${suite}" | tail -1
+			docker images "${repo}:${suite}-slim" | tail -1
 		fi
 	fi
+
+	find "$dir" \
+		\( \
+			-name '*.txt' \
+			-or -name '*.log' \
+		\) \
+		-exec sed -i \
+			-e 's!'"$PWD"'!/«BREWDIR»!g' \
+			-e 's!'"$(dirname "$mkimage")"'!/«MKIMAGEDIR»!g' \
+			'{}' +
 done