[arch-projects] [devtools] [RFC] makechrootpkg: add generic support for additional bind mounts

[Dave Reisner]

Piggyback on systemd-nspawn's --bind and --bind-ro flags to allow
arbitrary mount points to be added to the build container.

Signed-off-by: Dave Reisner <dreisner at archlinux.org>
---
This is untested, but is the result of a brief exchange I had with Pierre
on IRC. It was suggested that we provide generic support for adding bind
mounts rather than explicitly adding support for ccache (since all it
really requires is the extra bind mount).

 makechrootpkg.in | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/makechrootpkg.in b/makechrootpkg.in
index 1cd08fb..04ed04b 100644
--- a/makechrootpkg.in
+++ b/makechrootpkg.in
@@ -24,6 +24,9 @@ passeddir=
 declare -a install_pkgs
 declare -i ret=0
 
+bindmounts_ro=()
+bindmounts_rw=()
+
 copy=$USER
 [[ -n $SUDO_USER ]] && copy=$SUDO_USER
 [[ -z "$copy" || $copy = root ]] && copy=copy
@@ -48,6 +51,8 @@ usage() {
 	echo 'Flags:'
 	echo '-h         This help'
 	echo '-c         Clean the chroot before building'
+	echo '-d <dir>   Bind directory into build chroot as read-write'
+	echo '-D <dir>   Bind directory into build chroot as read-only'
 	echo '-u         Update the working copy of the chroot before building'
 	echo '           This is useful for rebuilds without dirtying the pristine'
 	echo '           chroot'
@@ -65,6 +70,8 @@ while getopts 'hcur:I:l:nT' arg; do
 	case "$arg" in
 		h) usage ;;
 		c) clean_first=true ;;
+		D) bindmounts_ro+=(--bind-ro="$OPTARG") ;;
+		d) bindmounts_rw+=(--bind="$OPTARG") ;;
 		u) update_first=true ;;
 		r) passeddir="$OPTARG" ;;
 		I) install_pkgs+=("$OPTARG") ;;
@@ -174,7 +181,9 @@ install_packages() {
 		pkgname="${install_pkg##*/}"
 		cp "$install_pkg" "$copydir/$pkgname"
 
-		arch-nspawn "$copydir" pacman -U /$pkgname --noconfirm
+		arch-nspawn "$copydir" \
+			"${bindmounts_ro[@]}" "${bindmounts_rw[@]}" \
+			pacman -U /$pkgname --noconfirm
 		(( ret += !! $? ))
 
 		rm "$copydir/$pkgname"
@@ -338,7 +347,9 @@ load_vars /etc/makepkg.conf
 
 create_chroot
 
-$update_first && arch-nspawn "$copydir" pacman -Syu --noconfirm
+$update_first && arch-nspawn "$copydir" \
+		"${bindmounts_ro[@]}" "${bindmounts_rw[@]}" \
+		pacman -Syu --noconfirm
 
 [[ -n ${install_pkgs[*]} ]] && install_packages
 
@@ -349,6 +360,7 @@ download_sources
 if arch-nspawn "$copydir" \
 	--bind-ro="$PWD:/startdir_host" \
 	--bind-ro="$SRCDEST:/srcdest_host" \
+	"${bindmounts_ro[@]}" "${bindmounts_rw[@]}" \
 	/chrootbuild
 then
 	move_products
-- 
1.8.3.4