osbuilder: Fix USE_DOCKER on s390x

- Install the required protobuf-compiler on Ubuntu
- Install correct libc Rust target (glibc on s390x)
- Do not skip Rust installation on s390x

Fixes: #1266

Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>

tools/osbuilder/rootfs-builder/ubuntu/Dockerfile.in

@@ -33,6 +33,7 @@ RUN apt-get update && apt-get --no-install-recommends install -y \
     musl \
     musl-dev \
     musl-tools \
+    protobuf-compiler \
     sed \
     systemd \
     tar \

tools/osbuilder/scripts/lib.sh

@@ -238,6 +238,7 @@ generate_dockerfile()
 	local architecture=$(uname -m)
 	local rustarch=${architecture}
 	local muslarch=${architecture}
+	local libc=musl
 	case "$(uname -m)" in
 		"ppc64le")
 			goarch=ppc64le
@@ -250,6 +251,7 @@ generate_dockerfile()
 			;;
 		"s390x")
 			goarch=s390x
+			libc=gnu
 			;;
 
 		*)
@@ -311,7 +313,7 @@ RUN . /root/.cargo/env; \
     export http_proxy=${http_proxy:-}; \
 	export https_proxy=${http_proxy:-}; \
 	cargo install cargo-when; \
-	rustup target install ${rustarch}-unknown-linux-musl
+	rustup target install ${rustarch}-unknown-linux-${libc}
 RUN ln -sf /usr/bin/g++ /bin/musl-g++
 "
 	# rust agent still need go to build
@@ -329,7 +331,7 @@ RUN ln -sf /usr/bin/g++ /bin/musl-g++
 	# powerpc have no musl target, don't setup rust enviroment
 	# since we cannot static link agent. Besides, there is
 	# also long double representation problem when building musl-libc
-	if [ "${architecture}" == "ppc64le" ] || [ "${architecture}" == "s390x" ]; then
+	if [ "${architecture}" == "ppc64le" ]; then
 		sed \
 			-e "s|@GO_VERSION@|${GO_VERSION}|g" \
 			-e "s|@OS_VERSION@|${OS_VERSION:-}|g" \
@@ -338,6 +340,17 @@ RUN ln -sf /usr/bin/g++ /bin/musl-g++
 			-e "s|@INSTALL_RUST@||g" \
 			-e "s|@SET_PROXY@|${set_proxy:-}|g" \
 			"${dockerfile_template}" > Dockerfile
+	# no musl target on s390x, will use GNU
+	elif [ "${architecture}" == "s390x" ]; then
+		sed \
+			-e "s|@GO_VERSION@|${GO_VERSION}|g" \
+			-e "s|@OS_VERSION@|${OS_VERSION:-}|g" \
+			-e "s|@INSTALL_CMAKE@|${install_cmake//$'\n'/\\n}|g" \
+			-e "s|@INSTALL_MUSL@||g" \
+			-e "s|@INSTALL_GO@|${install_go//$'\n'/\\n}|g" \
+			-e "s|@INSTALL_RUST@|${install_rust//$'\n'/\\n}|g" \
+			-e "s|@SET_PROXY@|${set_proxy:-}|g" \
+			"${dockerfile_template}" > Dockerfile
 	else
 		sed \
 			-e "s|@GO_VERSION@|${GO_VERSION}|g" \