Use multi-arch in dockerfile

This is necessary since the builder no longer passes the platform flag
to the build. This would lead to dockerfiles that are mixing multi and single
arch stages to pull the wrong architecture images, particularly when
trying to build images in emulated builds (e.g. armv7hf built on aarch64).

Moving the full build to multi-arch solves this as the docker engine is
capable of chosing the right architecture from the manifest.

Relatest-to: balena-io/balena-builder#1010
Change-type: patch

Dockerfile.template

@@ -1,43 +1,37 @@
 ARG ARCH=%%BALENA_ARCH%%
 ARG FATRW_VERSION=0.2.9
-
-
-FROM arm32v6/alpine:3.16 as alpine-rpi
-FROM arm32v7/alpine:3.16 as alpine-armv7hf
-FROM arm64v8/alpine:3.16 as alpine-aarch64
-FROM amd64/alpine:3.16 as alpine-amd64
-FROM i386/alpine:3.16 as alpine-i386
-
-FROM arm32v6/alpine:3.11 as procmail-rpi
-FROM arm32v7/alpine:3.11 as procmail-armv7hf
-FROM arm64v8/alpine:3.11 as procmail-aarch64
-FROM amd64/alpine:3.11 as procmail-amd64
-FROM i386/alpine:3.11 as procmail-i386
+ARG NODE="nodejs<18"
+ARG NPM="npm<9"
 
 ###################################################
 # Build the supervisor dependencies
 ###################################################
-FROM balenalib/${ARCH}-alpine-node:16-run as build-base
+FROM alpine:3.16 as build-base
 
 ARG ARCH
+ARG NODE
+ARG NPM
 ARG FATRW_VERSION
 ARG FATRW_ARCHIVE="fatrw-${ARCH}.tar.gz"
 ARG FATRW_LOCATION="https://github.com/balena-os/fatrw/releases/download/v${FATRW_VERSION}/${FATRW_ARCHIVE}"
 
 WORKDIR /usr/src/app
 
-RUN apk add --no-cache \
+RUN apk add --update --no-cache \
 	g++ \
 	make \
 	python3 \
-	libgcc \
+	curl \
+	$NODE \
+	$NPM \
 	libuv \
 	sqlite-dev \
-	dbus-dev
+	dbus-dev && \
+	npm install -g npm@8
 
 COPY package*.json ./
 
-RUN strip /usr/local/bin/node
+RUN strip "$(which node)"
 
 # Install fatrw
 RUN curl -SLO "${FATRW_LOCATION}" && \
@@ -55,7 +49,7 @@ RUN npm ci --build-from-source --sqlite=/usr/lib
 # musl. We hack around this by copying the binary and its library
 # dependencies to the final image
 ###################################################################
-FROM balenalib/${ARCH}-debian:bullseye-run as journal
+FROM debian:bullseye-slim as journal
 
 RUN apt-get update && apt-get install -y --no-install-recommends systemd
 
@@ -67,7 +61,7 @@ RUN /setup-journal.sh
 # Extra dependencies. This uses alpine 3.11 as the
 # procmail package was removed on 3.12
 ###################################################
-FROM procmail-${ARCH} as extra
+FROM alpine:3.11 as extra
 
 RUN apk add --update --no-cache procmail
 
@@ -75,13 +69,12 @@ RUN apk add --update --no-cache procmail
 # Image with the final production dependencies.
 # This image will also be be used for testing
 ###################################################
-FROM alpine-${ARCH} as runtime-base
+FROM alpine:3.16 as runtime-base
+
+ARG NODE
 
 WORKDIR /usr/src/app
 
-# We just need the node binary in the final image
-COPY --from=build-base /usr/local/bin/node /usr/local/bin/node
-
 # Also copy the fatrw binary
 COPY --from=build-base /usr/local/bin/fatrw /usr/local/bin/fatrw
 
@@ -92,13 +85,12 @@ COPY --from=extra /usr/bin/lockfile /usr/bin/lockfile
 COPY --from=journal /sysroot /
 
 # Runtime dependencies
-RUN apk add --no-cache \
-	ca-certificates \
+RUN apk add --update --no-cache \
+	$NODE \
 	iptables \
 	ip6tables \
 	rsync \
 	dbus \
-	libstdc++ \
 	dmidecode \
 	sqlite-libs
 
@@ -114,11 +106,14 @@ ENV CONFIG_MOUNT_POINT=/boot/config.json \
 ###############################################################
 FROM runtime-base as test
 
-WORKDIR /usr/src/app
+ARG NPM
+ARG ARCH
 
-# Copy node install from the build folder
-COPY --from=build-base /usr/local/bin /usr/local/bin
-COPY --from=build-base /usr/local/lib/node_modules /usr/local/lib/node_modules
+# We want to use as close to the final image when running tests
+# but we need npm so we install it here again
+RUN apk add --update --no-cache $NPM && npm install -g npm@8
+
+WORKDIR /usr/src/app
 
 # Copy build dependencies
 COPY --from=build-base /usr/src/app/package.json ./