Support multiarch through cross-compilation

Dockerfile

@@ -1,19 +1,48 @@
 ## builder
-FROM debian:10-slim as builder
+FROM --platform=$BUILDPLATFORM debian:stable-slim as builder
 LABEL image="ripe-atlas-builder"
+ARG BUILDPLATFORM
+ARG TARGETPLATFORM
 ARG DEBIAN_FRONTEND=noninteractive
 ARG GIT_URL=https://github.com/RIPE-NCC/ripe-atlas-software-probe.git
 
-RUN apt-get update -y \
-	&& apt-get install -y git tar fakeroot libssl-dev libcap2-bin autoconf automake libtool build-essential python
-
 WORKDIR /root
 
+RUN if [ "$BUILDPLATFORM" != "$TARGETPLATFORM" ] ; then \
+		case ${TARGETPLATFORM} in \
+			"linux/arm64")	echo 'export CROSSBUILD_ARCH=arm64 CROSS_COMPILE_TARGET=aarch64-linux-gnu' > env ;; \
+			"linux/arm/v6")	echo 'export CROSSBUILD_ARCH=armel CROSS_COMPILE_TARGET=arm-linux-gnueabi' > env ;; \
+			"linux/arm/v7")	echo 'export CROSSBUILD_ARCH=armhf CROSS_COMPILE_TARGET=arm-linux-gnueabihf' > env ;; \
+			"linux/386")	echo 'export CROSSBUILD_ARCH=i386 CROSS_COMPILE_TARGET=i686-linux-gnu' > env ;; \
+			"linux/amd64")	echo 'export CROSSBUILD_ARCH=amd64 CROSS_COMPILE_TARGET=x86_64-linux-gnu' > env ;; \
+			*) echo "Unsupported platform"; exit 1 ;; \
+		esac \
+		&& . ./env \
+		&& dpkg --add-architecture $CROSSBUILD_ARCH \
+		&& apt-get update -y \
+		&& apt-get install -y libssl-dev:$CROSSBUILD_ARCH crossbuild-essential-$CROSSBUILD_ARCH; \
+	fi \
+	&& apt-get update -y \
+	&& apt-get install -y git tar fakeroot libssl-dev libcap2-bin autoconf automake libtool build-essential
+
 RUN git clone --recursive "$GIT_URL"
-RUN ./ripe-atlas-software-probe/build-config/debian/bin/make-deb
+
+RUN if [ "$BUILDPLATFORM" != "$TARGETPLATFORM" ] ; then \
+		. ./env \
+		&& export CROSS_COMPILE="$CROSS_COMPILE_TARGET-" \
+		&& sed -i 's/.\/configure/.\/configure --host='$CROSS_COMPILE_TARGET'/g' ./ripe-atlas-software-probe/build-config/debian/bin/make-deb \
+		&& sed -i 's/ARCH=$(get_arch)/ARCH='$CROSSBUILD_ARCH'/g' ./ripe-atlas-software-probe/build-config/debian/bin/make-deb; \
+	fi \
+	&& ./ripe-atlas-software-probe/build-config/debian/bin/make-deb
+
+## artifacts
+FROM scratch AS artifacts
+LABEL image="ripe-atlas-artifacts"
+
+COPY --from=builder /root/atlasswprobe-*.deb /
 
 ## the actual image
-FROM debian:10-slim
+FROM debian:stable-slim
 LABEL maintainer="dockerhub@public.swineson.me"
 LABEL image="ripe-atlas"
 ARG DEBIAN_FRONTEND=noninteractive
@@ -46,4 +75,3 @@ VOLUME [ "/var/atlas-probe/etc", "/var/atlas-probe/status" ]
 
 ENTRYPOINT [ "entrypoint.sh" ]
 CMD [ "atlas" ]
-

README.md

@@ -12,13 +12,6 @@ This is the [RIPE Atlas software probe](https://atlas.ripe.net/docs/software-pro
 * A Linux installation with Docker installed
 * Internet access
 
-## Tags
-
-The following prebuilt tags are available at [Docker Hub](https://hub.docker.com/r/jamesits/ripe-atlas):
-
-* `latest`: For arm64 (x86\_64) devices
-* `latest-armv7l`: For armv7l (armhf) devices, e.g. Raspberry Pi (CI donated by [@OtakuNekoP](https://github.com/OtakuNekoP))
-
 ## Running
 
 First we start the container:
@@ -47,7 +40,9 @@ cat /var/atlas-probe/etc/probe_key.pub
 
 ### IPv6
 
-Docker's IPv6 support is still [like shit](https://github.com/moby/moby/issues/25407). As a workaround, you can use IPv6 NAT like this:
+Docker's IPv6 support is still [like shit](https://github.com/moby/moby/issues/25407). As a workaround, you can use IPv6 NAT using either `docker-ipv6nat` or native method (experimental).
+
+First, edit kernel parameters.
 
 ```shell
 cat > /etc/sysctl.d/50-docker-ipv6.conf <<EOF
@@ -56,13 +51,31 @@ net.ipv6.conf.all.forwarding=1
 net.ipv6.conf.default.forwarding=1
 EOF
 sysctl -p /etc/sysctl.d/50-docker-ipv6.conf
+```
+
+Note this might break your network and your mileage may vary. You should swap `eth0` with your primary network adapter name, and if you use static IPv6 assignment instead of SLAAC, change `accept_ra` to `0`.
+
+#### Using robbertkl/docker-ipv6nat
+
+```shell
 docker network create --ipv6 --subnet=fd00:a1a3::/48 ripe-atlas-network
 docker run -d --restart=always -v /var/run/docker.sock:/var/run/docker.sock:ro -v /lib/modules:/lib/modules:ro --cap-drop=ALL --cap-add=NET_RAW --cap-add=NET_ADMIN --cap-add=SYS_MODULE --net=host --name=ipv6nat robbertkl/ipv6nat:latest
 ```
 
 Then start the RIPE Atlas container with argument `--net=ripe-atlas-network`. 
 
-Note this might break your network and your mileage may vary. You should swap `eth0` with your primary network adapter name, and if you use static IPv6 assignment instead of SLAAC, change `accept_ra` to `0`.
+#### Using native method (experimental)
+
+Edit `/etc/docker/daemon.json`, then restart docker daemon.
+
+```json
+{
+  "experimental": true,
+  "ipv6": true,
+  "ip6tables": true,
+  "fixed-cidr-v6": "fd00:a1a3::/48"
+}
+```
 
 ### Auto Update
 
@@ -78,3 +91,6 @@ Then start the RIPE Atlas container with argument `--label=com.centurylinklabs.w
 
 All the config files are stored at `/var/atlas-probe`. Just backup it.
 
+### BuildKit
+
+The `Dockerfile` requires [BuildKit](https://docs.docker.com/develop/develop-images/build_enhancements/).