Refactor mkimage-debootstrap.sh to be much more full-featured

This includes the following:
- options to control certain parameters
- an option specifically for creating tarballs directly, esp. for dockerbrew
- the addition of the updates and security repositories for Debian images
- the addition of the universe, updates, and security repositories for Ubuntu images
- more correct tagging of Debian images
- tagging of Ubuntu image versions (12.04, 12.10, etc) and latest tag for LTS

contrib/mkimage-debootstrap.sh

@@ -1,31 +1,114 @@
 #!/bin/bash
 set -e
 
-# these should match the names found at http://www.debian.org/releases/
-stableSuite='wheezy'
-testingSuite='jessie'
-unstableSuite='sid'
-
 variant='minbase'
 include='iproute,iputils-ping'
+arch='amd64' # intentionally undocumented for now
+skipDetection=
+strictDebootstrap=
+justTar=
+
+usage() {
+	echo >&2
+	
+	echo >&2 "usage: $0 [options] repo suite [mirror]"
+	
+	echo >&2
+	echo >&2 'options: (not recommended)'
+	echo >&2 "  -v $variant # change default debootstrap variant"
+	echo >&2 "  -i $include # change default package includes"
+	echo >&2 "  -d # strict debootstrap (do not apply any docker-specific tweaks)"
+	echo >&2 "  -s # skip version detection and tagging (ie, precise also tagged as 12.04)"
+	echo >&2 "     # note that this will also skip adding universe and/or security/updates to sources.list"
+	echo >&2 "  -t # just create a tarball, especially for dockerbrew (uses repo as tarball name)"
+	
+	echo >&2
+	echo >&2 "   ie: $0 username/debian squeeze"
+	echo >&2 "       $0 username/debian squeeze http://ftp.uk.debian.org/debian/"
+	
+	echo >&2
+	echo >&2 "   ie: $0 username/ubuntu precise"
+	echo >&2 "       $0 username/ubuntu precise http://mirrors.melbourne.co.uk/ubuntu/"
+	
+	echo >&2
+	echo >&2 "   ie: $0 -t precise.tar.bz2 precise"
+	echo >&2 "       $0 -t wheezy.tgz wheezy"
+	echo >&2 "       $0 -t wheezy-uk.tar.xz wheezy http://ftp.uk.debian.org/debian/"
+	
+	echo >&2
+}
+
+# these should match the names found at http://www.debian.org/releases/
+debianStable=wheezy
+debianUnstable=sid
+# this should match the name found at http://releases.ubuntu.com/
+ubuntuLatestLTS=precise
+
+while getopts v:i:a:dst name; do
+	case "$name" in
+		v)
+			variant="$OPTARG"
+			;;
+		i)
+			include="$OPTARG"
+			;;
+		a)
+			arch="$OPTARG"
+			;;
+		d)
+			strictDebootstrap=1
+			;;
+		s)
+			skipDetection=1
+			;;
+		t)
+			justTar=1
+			;;
+		?)
+			usage
+			exit 0
+			;;
+	esac
+done
+shift $(($OPTIND - 1))
 
 repo="$1"
 suite="$2"
 mirror="${3:-}" # stick to the default debootstrap mirror if one is not provided
 
 if [ ! "$repo" ] || [ ! "$suite" ]; then
-	echo >&2 "usage: $0 repo suite [mirror]"
-	echo >&2
-	echo >&2 "   ie: $0 tianon/debian squeeze"
-	echo >&2 "       $0 tianon/debian squeeze http://ftp.uk.debian.org/debian/"
-	echo >&2
-	echo >&2 "   ie: $0 tianon/ubuntu precise"
-	echo >&2 "       $0 tianon/ubuntu precise http://mirrors.melbourne.co.uk/ubuntu/"
-	echo >&2
+	usage
 	exit 1
 fi
 
-target="/tmp/docker-rootfs-debian-$suite-$$-$RANDOM"
+# some rudimentary detection for whether we need to "sudo" our docker calls
+docker=''
+if docker version > /dev/null 2>&1; then
+	docker='docker'
+elif sudo docker version > /dev/null 2>&1; then
+	docker='sudo docker'
+elif command -v docker > /dev/null 2>&1; then
+	docker='docker'
+else
+	echo >&2 "warning: either docker isn't installed, or your current user cannot run it;"
+	echo >&2 "         this script is not likely to work as expected"
+	sleep 3
+	docker='docker' # give us a command-not-found later
+fi
+
+# make sure we have an absolute path to our final tarball so we can still reference it properly after we change directory
+if [ "$justTar" ]; then
+	if [ ! -d "$(dirname "$repo")" ]; then
+		echo >&2 "error: $(dirname "$repo") does not exist"
+		exit 1
+	fi
+	repo="$(cd "$(dirname "$repo")" && pwd -P)/$(basename "$repo")"
+fi
+
+# will be filled in later, if [ -z "$skipDetection" ]
+lsbDist=''
+
+target="/tmp/docker-rootfs-debootstrap-$suite-$$-$RANDOM"
 
 cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
 returnTo="$(pwd -P)"
@@ -34,48 +117,111 @@ set -x
 
 # bootstrap
 mkdir -p "$target"
-sudo debootstrap --verbose --variant="$variant" --include="$include" "$suite" "$target" "$mirror"
+sudo debootstrap --verbose --variant="$variant" --include="$include" --arch="$arch" "$suite" "$target" "$mirror"
 
 cd "$target"
 
-# prevent init scripts from running during install/update
-#  policy-rc.d (for most scripts)
-echo $'#!/bin/sh\nexit 101' | sudo tee usr/sbin/policy-rc.d > /dev/null
-sudo chmod +x usr/sbin/policy-rc.d
-#  initctl (for some pesky upstart scripts)
-sudo chroot . dpkg-divert --local --rename --add /sbin/initctl
-sudo ln -sf /bin/true sbin/initctl
-# see https://github.com/dotcloud/docker/issues/446#issuecomment-16953173
-
-# shrink the image, since apt makes us fat (wheezy: ~157.5MB vs ~120MB)
-sudo chroot . apt-get clean
-
-# while we're at it, apt is unnecessarily slow inside containers
-#  this forces dpkg not to call sync() after package extraction and speeds up install
-#    the benefit is huge on spinning disks, and the penalty is nonexistent on SSD or decent server virtualization
-echo 'force-unsafe-io' | sudo tee etc/dpkg/dpkg.cfg.d/02apt-speedup > /dev/null
-#  we want to effectively run "apt-get clean" after every install to keep images small
-echo 'DPkg::Post-Invoke {"/bin/rm -f /var/cache/apt/archives/*.deb || true";};' | sudo tee etc/apt/apt.conf.d/no-cache > /dev/null
-
-# helpful undo lines for each the above tweaks (for lack of a better home to keep track of them):
-#  rm /usr/sbin/policy-rc.d
-#  rm /sbin/initctl; dpkg-divert --rename --remove /sbin/initctl
-#  rm /etc/dpkg/dpkg.cfg.d/02apt-speedup
-#  rm /etc/apt/apt.conf.d/no-cache
-
-# create the image (and tag $repo:$suite)
-sudo tar -c . | docker import - $repo $suite
-
-# test the image
-docker run -i -t $repo:$suite echo success
-
-if [ "$suite" = "$stableSuite" -o "$suite" = 'stable' ]; then
-	# tag latest
-	docker tag $repo:$suite $repo latest
+if [ -z "$strictDebootstrap" ]; then
+	# prevent init scripts from running during install/update
+	#  policy-rc.d (for most scripts)
+	echo $'#!/bin/sh\nexit 101' | sudo tee usr/sbin/policy-rc.d > /dev/null
+	sudo chmod +x usr/sbin/policy-rc.d
+	#  initctl (for some pesky upstart scripts)
+	sudo chroot . dpkg-divert --local --rename --add /sbin/initctl
+	sudo ln -sf /bin/true sbin/initctl
+	# see https://github.com/dotcloud/docker/issues/446#issuecomment-16953173
+	
+	# shrink the image, since apt makes us fat (wheezy: ~157.5MB vs ~120MB)
+	sudo chroot . apt-get clean
+	
+	# while we're at it, apt is unnecessarily slow inside containers
+	#  this forces dpkg not to call sync() after package extraction and speeds up install
+	#    the benefit is huge on spinning disks, and the penalty is nonexistent on SSD or decent server virtualization
+	echo 'force-unsafe-io' | sudo tee etc/dpkg/dpkg.cfg.d/02apt-speedup > /dev/null
+	#  we want to effectively run "apt-get clean" after every install to keep images small
+	echo 'DPkg::Post-Invoke {"/bin/rm -f /var/cache/apt/archives/*.deb || true";};' | sudo tee etc/apt/apt.conf.d/no-cache > /dev/null
+	
+	# helpful undo lines for each the above tweaks (for lack of a better home to keep track of them):
+	#  rm /usr/sbin/policy-rc.d
+	#  rm /sbin/initctl; dpkg-divert --rename --remove /sbin/initctl
+	#  rm /etc/dpkg/dpkg.cfg.d/02apt-speedup
+	#  rm /etc/apt/apt.conf.d/no-cache
+	
+	if [ -z "$skipDetection" ]; then
+		# see also rudimentary platform detection in hack/install.sh
+		lsbDist=''
+		if [ -r etc/lsb-release ]; then
+			lsbDist="$(. etc/lsb-release && echo "$DISTRIB_ID")"
+		fi
+		if [ -z "$lsbDist" ] && [ -r etc/debian_version ]; then
+			lsbDist='Debian'
+		fi
+		
+		case "$lsbDist" in
+			Debian)
+				# add the updates and security repositories
+				if [ "$suite" != "$debianUnstable" -a "$suite" != 'unstable' ]; then
+					# ${suite}-updates only applies to non-unstable
+					sudo sed -i "p; s/ $suite main$/ ${suite}-updates main/" etc/apt/sources.list
+					
+					# same for security updates
+					echo "deb http://security.debian.org/ $suite/updates main" | sudo tee -a etc/apt/sources.list > /dev/null
+				fi
+				;;
+			Ubuntu)
+				# add the universe, updates, and security repositories
+				sudo sed -i "
+					s/ $suite main$/ $suite main universe/; p;
+					s/ $suite main/ ${suite}-updates main/; p;
+					s/ $suite-updates main/ ${suite}-security main/
+				" etc/apt/sources.list
+				;;
+		esac
+	fi
+fi
+
+if [ "$justTar" ]; then
+	# create the tarball file so it has the right permissions (ie, not root)
+	touch "$repo"
+	
+	# fill the tarball
+	sudo tar -caf "$repo" .
+else
+	# create the image (and tag $repo:$suite)
+	sudo tar -c . | $docker import - $repo $suite
+	
+	# test the image
+	$docker run -i -t $repo:$suite echo success
 	
-	# tag the specific debian release version
-	ver=$(docker run $repo:$suite cat /etc/debian_version)
-	docker tag $repo:$suite $repo $ver
+	if [ -z "$skipDetection" ]; then
+		case "$lsbDist" in
+			Debian)
+				if [ "$suite" = "$debianStable" -o "$suite" = 'stable' ] && [ -r etc/debian_version ]; then
+					# tag latest
+					$docker tag $repo:$suite $repo latest
+					
+					if [ -r etc/debian_version ]; then
+						# tag the specific debian release version (which is only reasonable to tag on debian stable)
+						ver=$(cat etc/debian_version)
+						$docker tag $repo:$suite $repo $ver
+					fi
+				fi
+				;;
+			Ubuntu)
+				if [ "$suite" = "$ubuntuLatestLTS" ]; then
+					# tag latest
+					$docker tag $repo:$suite $repo latest
+				fi
+				if [ -r etc/lsb-release ]; then
+					lsbRelease="$(. etc/lsb-release && echo "$DISTRIB_RELEASE")"
+					if [ "$lsbRelease" ]; then
+						# tag specific Ubuntu version number, if available (12.04, etc.)
+						$docker tag $repo:$suite $repo $lsbRelease
+					fi
+				fi
+				;;
+		esac
+	fi
 fi
 
 # cleanup