update-system

#!/bin/sh

####################################################################################################
# User-serviceable definitions
####################################################################################################

GIT_CLIENT_PACKAGE='git-tiny'
GIT_FETCH_ARGS='--depth=1'
GIT_RESET_ARGS='--keep'
MAKE_ARGS="-j$(sysctl -n hw.ncpu)"
MERGEMASTER_ARGS='-FiU'
PREFER_ETCUPDATE=1

####################################################################################################
# Internal definitions
####################################################################################################

KERNCONF_PATH="/usr/src/sys/$(uname -m)/conf"
MY_PATH="$(dirname "$(readlink -f "$0")")"
SRC_PATH='/usr/src'

####################################################################################################
# Utility functions
####################################################################################################

. "$MY_PATH/common"

# backs up GENERIC and UPDATING so that they can be compared post-upgrade
back_up_generic_and_updating() {
	if [ -f "$KERNCONF_PATH/GENERIC" ] ; then
		cp -fv "$KERNCONF_PATH/GENERIC" "$KERNCONF_PATH/GENERIC.last"
	fi
	if [ -f "$SRC_PATH/UPDATING" ]; then
		cp -fv "$SRC_PATH/UPDATING" "$SRC_PATH/UPDATING.last"
	fi
}

# determines whether etcupdate(8) needs bootstrapping
check_etcupdate() {
	if [ "$PREFER_ETCUPDATE" -a ! "$(is_etcupdate_functional)" ]; then
		line1="etcupdate(8) is set as the preferred configuration merging tool, but it needs"
		line2="to be bootstrapped before its first use. Bootstrapping consists of making a copy"
		line3="of the stock configuration in $SRC_PATH (which should match the currently running"
		line4="world) and establishing it as the baseline for detecting local changes."
		echo -e "$line1\n$line2\n$line3\n$line4"
		prompt '[B]ootstrap and use etcupdate(8), or [f]all back to mergemaster(8)?'
		selection="$(input '[bBfF]')"
		case "$selection" in
			b|B)	echo -n '    Bootstrapping etcupdate(8); please wait... '
					etcupdate extract || exit 1
					echo 'done.'
					;;
			f|F)	echo '    Falling back to mergemaster(8).'
					;;
		esac
	fi
}

# determines whether etcupdate(8) has been bootstrapped and is functional
is_etcupdate_functional() {
	etcupdate diff > /dev/null 2>&1 && echo 1
}

# determines whether the given string is a valid FreeBSD source repository URL
# $1: source repository URL
is_repository_url() {
	branch_regexp='head|stable/[[:digit:]]+|releng/[[:digit:]]+\.[[:digit:]]+'
	is_match "$1" "^https?://[-.[:alnum:]]+/base/($branch_regexp)/?$" -i
}

# shows help
print_usage() {
	echo "Usage: $0 --stage1 [kernconf]"
	indent=$(("$(echo "$0" | wc -m)" + 7))
	repeat ' ' $indent; echo '--stage2'
	repeat ' ' $indent; echo '--stage3'
	echo 'Stages:'
	echo '    --stage1: Updates the source tree, shows changes in UPDATING, merges'
	echo '              inbound changes to GENERIC into `kernconf` (if one is given),'
	echo '              builds the userland, and builds and installs the kernel.'
	echo '      [kernconf]: File name (not path) of the kernel configuration to build.'
	echo '              Defaults to GENERIC if unspecified.'
	echo '    --stage2: Installs the userland and merges changes in configuration files.'
	echo '    --stage3: Upgrades pkg(8), cleans build output, and removes obsolete files.'
	echo
}

# builds world and kernel, and installs kernel
# $1: kernconf (optional; defaults to GENERIC)
stage1() {
	# determine kernel to build
	if [ -n "$1" ]; then
		if [ -f "$KERNCONF_PATH/$1" ]; then
			KERNCONF="$1"
		else
			echo "Kernel configuration file not found: $KERNCONF_PATH/$1"
			exit 1
		fi
	else
		KERNCONF='GENERIC'
	fi
	echo -e "\nKernel configuration: $KERNCONF"

	# determine the type of source repository and whether the appropriate VCS client is installed
	is_git_repository=
	if [ -d "$SRC_PATH/.git" ]; then
		is_git_repository=1
		MERGEMASTER_ARGS="$MERGEMASTER_ARGS -s" # don't rely on VCS IDs for comparison
		check_git_client "$SRC_PATH" "$GIT_CLIENT_PACKAGE" || exit 1
	else
		check_subversion_client "$SRC_PATH" || exit 1
	fi

	# confirm and sync source branch to be built
	branch=
	if [ "$is_git_repository" ]; then
		branch="$(git rev-parse --abbrev-ref HEAD)"
	else
		branch="$(svnlite info "$SRC_PATH" | grep '^URL' | awk '{print $2}')"
	fi
	if [ -z "$branch" ]; then
		echo
		echo -n "Unable to determine current the source tree branch. Please verify that $SRC_PATH "
		echo    "is a valid repository."
		exit 1
	fi
	prompt_Yn "Keep the same branch, $branch?"
	# if staying on the same branch
	if [ $(confirm) ]; then
		prompt_Yn 'Sync source tree?'
		if [ $(confirm) ]; then
			# back up GENERIC and UPDATING so that they can be compared post-sync
			back_up_generic_and_updating
			# sync source tree
			if [ "$is_git_repository" ]; then
				# TODO: switch to `make update` once Makefile migrates to Git
				git fetch $GIT_FETCH_ARGS && git reset $GIT_RESET_ARGS origin/$branch || exit 1
			else
				NO_PORTSUPDATE=yes make update || exit 1
			fi
		fi
	# if switching branches
	else
		branch_regexp='head|stable/[[:digit:]]+|releng/[[:digit:]]+\.[[:digit:]]+'
		if [ "$is_git_repository" ]; then
			prompt 'New branch (e.g. releng/xx.y):'
			branch="$(input "$branch_regexp")"
		else
			prompt 'New repository URL (e.g. https://svn.freebsd.org/base/releng/xx.y):'
			repository_url="$(input "https?://[-.[:alnum:]]+/base/($branch_regexp)/?")"
		fi
		# back up GENERIC and UPDATING so that they can be compared post-sync
		back_up_generic_and_updating
		# switch branches and sync source tree
		if [ "$is_git_repository" ]; then
			git fetch $GIT_FETCH_ARGS && git checkout "$branch" && \
				git reset $GIT_RESET_ARGS origin/$branch || exit 1
		else
			svnlite switch "$repository_url" || exit 1
		fi
	fi

	# if we have a backup of UPDATING and it differs from the latest, display the differences
	if [ -f "$SRC_PATH/UPDATING.last" -a \
			$(are_files_different "$SRC_PATH/UPDATING" "$SRC_PATH/UPDATING.last") ]; then
		prompt_Yn 'See changes in UPDATING?'
		if [ $(confirm) ]; then
			diff -ruN "$SRC_PATH/UPDATING.last" "$SRC_PATH/UPDATING" | less --QUIT-AT-EOF
		fi
	# otherwise, offer to display the whole file
	else
		prompt_Yn 'Read UPDATING?'
		if [ $(confirm) ]; then
			less --QUIT-AT-EOF "$SRC_PATH/UPDATING"
		fi
	fi

	# clean and build world
	prompt_Yn "Build the userland (\`make $MAKE_ARGS buildworld\`)?"
	if [ $(confirm) ]; then
		if [ ! "$PREFER_ETCUPDATE" -o ! "$(is_etcupdate_functional)" ]; then
			prompt_Yn "Merge pre-buildworld configuration with \`mergemaster $MERGEMASTER_ARGS -p\`?"
			if [ $(confirm) ]; then
				mergemaster $MERGEMASTER_ARGS -p || exit 1
			fi
		fi
		no_clean_arg=
		prompt_Yn 'Clean the build directory before building?'
		if [ ! $(confirm) ]; then
			no_clean_arg='-DNO_CLEAN'
		fi
		make $MAKE_ARGS $no_clean_arg buildworld || exit 1
	fi

	# build kernel
	prompt_Yn "Build the $KERNCONF kernel (\`make $MAKE_ARGS buildkernel KERNCONF=$KERNCONF\`)?"
	if [ $(confirm) ]; then
		# if building a custom kernel configuration, merge changes from GENERIC into it
		custom_kernconf="$KERNCONF_PATH/$KERNCONF"
		generic_kernconf="$KERNCONF_PATH/GENERIC"
		if [ "$KERNCONF" != 'GENERIC' -a \
				$(are_files_different "$generic_kernconf" "$custom_kernconf") ]; then
			three_way_merge_files "$generic_kernconf.last" "$generic_kernconf" "$custom_kernconf"
		fi
		# build
		make $MAKE_ARGS buildkernel KERNCONF="$KERNCONF" || exit 1
	fi

	# install kernel
	prompt_Yn "Install the $KERNCONF kernel (\`make installkernel KERNCONF=$KERNCONF\`)?"
	if [ $(confirm) ]; then
		make $MAKE_ARGS installkernel KERNCONF="$KERNCONF" || exit 1
		prompt_Yn "Reboot and activate the new $KERNCONF kernel?"
		if [ $(confirm) ]; then
			echo; header "After the reboot, run \`$0 --stage2\` to continue."; echo
			sleep 3
			shutdown -r now
		fi
	fi
}

# installs world and merges configuration
stage2() {
	if [ "$PREFER_ETCUPDATE" -a "$(is_etcupdate_functional)" ]; then
		prompt_Yn 'Merge pre-installworld configuration with `etcupdate -p`?'
		if [ $(confirm) ]; then
			etcupdate -p || exit 1
		fi
	fi

	prompt_Yn 'Install the userland (`make installworld`)?'
	world_installed=
	if [ $(confirm) ]; then
		make installworld || exit 1
		world_installed=1
	fi

	if [ "$PREFER_ETCUPDATE" -a "$(is_etcupdate_functional)" ]; then
		prompt_Yn 'Merge configuration files with `etcupdate -B`?'
		if [ $(confirm) ]; then
			etcupdate -B || (
				prompt_Yn 'Resolve conflicts with `etcupdate resolve`?'
				if [ $(confirm) ]; then
					etcupdate resolve || exit 1
				else
					exit 1
				fi
			)
		fi
	else
		prompt_Yn "Merge configuration files with \`mergemaster $MERGEMASTER_ARGS\`?"
		if [ $(confirm) ]; then
			mergemaster $MERGEMASTER_ARGS || exit 1
		fi
	fi

	if [ "$world_installed" ]; then
		prompt_Yn 'Reboot into the new userland?'
		if [ $(confirm) ]; then
			echo; header "After the reboot, run \`$0 --stage3\` to continue."; echo
			sleep 3
			shutdown -r now
		fi
	fi
}

# upgrades pkg(8) and cleans up after the build
stage3() {
	if [ "$(which pkg-static)" ]; then
		prompt_Yn 'Upgrade pkg(8)?'
		if [ $(confirm) ]; then
			pkg-static install pkg || ASSUME_ALWAYS_YES=yes pkg-static bootstrap -f
		fi
	fi

	prompt_Yn 'Clean up obsolete files and directories (`make delete-old`)?'
	if [ $(confirm) ]; then
		yes | make delete-old
	fi

	prompt 'Checking for obsolete shared libraries...'
	redundant_shlibs="$(make check-old-libs)"
	if [ ! "$redundant_shlibs" = ">>> Checking for old libraries" ]; then
		echo 'none found.'
	else
		echo -e "$redundant_shlibs" | less --QUIT-AT-EOF
		message='Delete ALL redundant shared libraries listed above?\n'
		message="$message    WARNING: There may be ports still using some of these libraries."
		prompt_yN "$message"
		if [ $(confirm 'n') ]; then
			yes | make delete-old-libs > /dev/null
		else
			prompt_Yn 'Interactively delete redundant shared libraries one at a time?'
			if [ $(confirm) ]; then
				make delete-old-libs
			fi
		fi
	fi

	message='Clean the build directory (`make cleanworld`)? Answer affirmatively if\n'
	message="$message    you are satisfied with the upgrade and have no further use for the build\n"
	message="$message    output (e.g. upgrading other hosts from the built binaries)."
	prompt_yN "$message"
	if [ $(confirm 'n') ]; then
		make cleanworld
	fi
}

# changes into the source directory and executes the requested stage
stage_switchboard() {
	cd "$SRC_PATH" || exit 1

	# execute requested stage
	case "$1" in
		1)	check_etcupdate
			stage1 "$2";;
		2)	check_etcupdate
			stage2;;
		3)	stage3;;
	esac
}

####################################################################################################
# Entry point
####################################################################################################

case "$1" in
	--stage1)	stage_switchboard 1 "$2";;
	--stage2)	stage_switchboard 2;;
	--stage3)	stage_switchboard 3;;
	*)			print_usage
				exit 1;;
esac