install-build-deps.sh has --dont-install and --platform options.

All docker files do not call isntall-build-deps.sh. Instead, cmake passes
REQUIREDPKGS to Dockerfiles, which is derived from the output of
./scripts/install-build-deps.sh --dont-install --platform PLATFORM.
This change enables caching package installaion during docker build.

scripts/install-build-deps.sh

@@ -3,34 +3,71 @@
 # Install build dpenedencies.
 
 set -e
-set -u
+#set -u
+
+function print_help() {
+	echo "$0 [options]"
+	echo "    --dont-install         Print required packages."
+	echo "    --platform [PLATFORM]  PLATFORM is Kernel-ID, e.g., Linux-ubuntu."
+	echo "                           Automatically detected if not specified."
+}
 
 platform=$(uname -s)
+doinstall=1
 
 if [ -e /etc/os-release ]; then
 	source /etc/os-release
 	platform=${platform}-${ID}
 fi
 
-set -x
+while getopts h-: opt; do
+        optarg="${!OPTIND}"
+        [[ "$opt" = - ]] && opt="-$OPTARG"
+	case "-${opt}" in
+		--dont-install)
+			doinstall=0
+			;;
+		--platform)
+			platform=$optarg
+			shift
+			;;
+		-h)
+			print_help
+			exit 0
+			;;
+		*)
+			print_help
+			exit 1
+			;;
+	esac
+done
 
 case $platform in
 	Darwin)
-		brew install openssl@1.1
+		cmd="brew install"
+		pkgs="openssl@1.1"
 		;;
 	Linux-ubuntu*)
-		apt-get install --no-install-recommends -y \
-			gcc make cmake zlib1g-dev libssl-dev libkrb5-dev
+		cmd="apt-get install --no-install-recommends -y"
+		pkgs="gcc make cmake zlib1g-dev libssl-dev libkrb5-dev"
 		;;
 	Linux-centos* | Linux-rhel* | Linux-rocky* | Linux-almalinux)
-		yum install -y \
-			gcc make cmake zlib-devel openssl-devel rpm-build
+		cmd="yum install -y"
+		pkgs="gcc make cmake zlib-devel openssl-devel rpm-build"
 		;;
 	FreeBSD-freebsd)
-		pkg install cmake
+		cmd="pkg install"
+		pkgs="cmake"
 		;;
 	*)
 		echo "unsupported platform: $platform"
 		exit 1
 		;;
 esac
+
+if [ $doinstall -gt 0 ]; then
+	echo do "$cmd $pkgs"
+	$cmd $pkgs
+else
+	echo $pkgs
+fi