admin: multiarch add enable/disable with warning

1 files changed, 40 insertions, 5 deletions

diff --git a/dabuild-admin b/dabuild-admin
index a235f24..6303e9c 100755
--- a/dabuild-admin
+++ b/dabuild-admin
@@ -4,6 +4,24 @@ set -eu
 
 readonly cmd=${1:-help}
 
+die() {
+	echo "$@" >&2
+	exit 1
+}
+
+ask() {
+	local question="$1"
+	while true; do
+		# SC2039 -p is non posix but widely available
+		read -rp "$question" yn
+		case $yn in
+			[Yy]) return 0;;
+			[Nn]) exit;;
+			*) echo "Please answer y/n.";;
+		esac
+	done
+}
+
 manage_config() {
 	docker run --user 1000:1000 --rm -it --workdir /mnt/abuild \
 		-v dabuild-config:/mnt/abuild alpine sh
@@ -13,9 +31,27 @@ list_volumes() {
 	docker volume ls --quiet --filter name="^dabuild"
 }
 
-enable_multiarch() {
-	docker run --rm --privileged multiarch/qemu-user-static \
-		--reset --persistent yes --credential yes
+multiarch() {
+	case "${2:-help}" in
+		enable) ask "Are you sure you want to enable multi-arch system wide? (y/n): "
+			docker run --rm --privileged multiarch/qemu-user-static \
+				--reset --persistent yes --credential yes ;;
+		disable) sudo --prompt="Sudo password:" find /proc/sys/fs/binfmt_misc \
+			-type f -name 'qemu-*' -exec sh -c 'echo -1 > {}' \; ;;
+		help) multiarch_usage ;;
+		*) die "Unknown subcommand \"$2\"" ;;
+	esac
+}
+
+multiarch_usage() {
+	cat <<- EOF
+	dabuild: version (unknown)
+
+	Available subcommands:
+	  enable: enable multi-arch support via binfmt_misc
+	  disable: disable mutli-arch support
+	  help: this help screen
+	EOF
 }
 
 usage() {
@@ -30,11 +66,10 @@ usage() {
 	EOF
 }
 
-
 case $cmd in
 	config) manage_config;;
 	volumes) list_volumes;;
-	multiarch) enable_multiarch;;
+	multiarch) multiarch "$@";;
 	help) usage;;
 	*) usage; exit 1;;
 esac