Add mkzensical build wrapper script

mkzensical/.local/bin/mkzensical

@@ -11,17 +11,30 @@ err() {
 }
 
 usage() {
-	printf 'usage: %s <zensical-semver> <repo-dir> [selinux-context]\n' "$prog" >&2
+	printf 'usage: %s [-z] <zensical_version> <repo_dir>\n' "$prog" >&2
 }
 
-if (($# != 2 && $# != 3)); then
+selinux=0
+while getopts ':z' opt; do
+	case $opt in
+	z)
+		selinux=1
+		;;
+	*)
+		usage
+		exit 1
+		;;
+	esac
+done
+shift $((OPTIND - 1))
+
+if (($# != 2)); then
 	usage
 	exit 1
 fi
 
 tag=$1
 dir=$2
-label=$3
 
 if [[ ! $tag =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
 	err "tag must be a version like 1.2.3 (got: $tag)"
@@ -44,12 +57,12 @@ git pull -q --ff-only || err "failed to update repo"
 new=$(git rev-parse HEAD) || err "git rev-parse failed after pull at: $(pwd)"
 
 if [[ $old != "$new" || ! -d site ]]; then
-	if ! docker run --rm -v "$PWD:/docs" "zensical/zensical:$tag" build; then
+	docker_opts=(run --rm)
+	[[ $selinux -eq 1 ]] && docker_opts+=(--security-opt label=level:s0)
+	docker_opts+=(-v "$PWD:/docs" "zensical/zensical:$tag" build)
+	if ! docker "${docker_opts[@]}"; then
 		err "build failed"
 	fi
 fi
 
 [[ -d site ]] || err "build did not produce site directory"
-if [[ -n $label ]]; then
-	chcon -R -- "$label" site || err "failed to change SELinux context: $label"
-fi