Basic alpine chroot

alpine/build-rootfs.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+

alpine/prepare-chroot.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+mkdir -p "$ROOTFS/var/cache/apk"
+mount --bind /var/cache/apk "$ROOTFS/var/cache/apk"
+mount --bind /dev  "$ROOTFS/dev"
+mount --bind /proc "$ROOTFS/proc"
+mount --bind /sys  "$ROOTFS/sys"
+mount --bind /run  "$ROOTFS/run"
+
+cp /usr/bin/qemu-aarch64-static "$ROOTFS/usr/bin/"
+cp /etc/resolv.conf "$ROOTFS/etc/resolv.conf"
+
+chroot "$ROOTFS" /bin/sh -c "ln -s /var/cache/apk /etc/apk/cache"
+chroot "$ROOTFS" /bin/sh -c "apk update; apk add bash curl"
+cp "/build-rootfs.sh" "$ROOTFS/build-rootfs.sh"
+chroot "$ROOTFS" /bin/bash /build-rootfs.sh

build.env

@@ -19,3 +19,6 @@ CROSS_COMPILE=aarch64-linux-gnu-
 # Busybox for initramfs
 BUSYBOX_VERSION=1_36_1
 
+## Alpine Linux
+ALPINE_VER=3.23.3
+ALPINE_ARCH=aarch64

docker/alpine.Dockerfile

@@ -0,0 +1,22 @@
+ARG TAG=dev
+ARG DOCKER_IMAGE_ROOT=monok8s
+FROM --platform=linux/amd64 ${DOCKER_IMAGE_ROOT}/build-base:${TAG} AS build-base
+
+ARG ALPINE_ARCH
+ARG ALPINE_VER
+
+RUN apt-get update && apt-get install -y qemu-user-static --no-install-recommends
+
+RUN mkdir -p "/out/rootfs"
+
+# RUN curl -L \
+#   "https://dl-cdn.alpinelinux.org/alpine/v3.21/releases/${ALPINE_ARCH}/alpine-minirootfs-${ALPINE_VER}-${ALPINE_ARCH}.tar.gz" \
+#   -o alpine-minirootfs.tar.gz
+# RUN tar -xzf alpine-minirootfs.tar.gz -C "/out/rootfs"
+
+# Dev-only shortcut
+COPY dev/alpine.tar.gz ./
+
+RUN tar -xf alpine.tar.gz -C "/out/rootfs"
+
+COPY alpine/*.sh /

makefile

@@ -39,3 +39,21 @@ itb: fit-build
 		--build-arg DEVICE_TREE_TARGET=$(DEVICE_TREE_TARGET) \
 		--output type=local,dest=./out \
 	-t $(DOCKER_IMAGE_ROOT)/itb:$(TAG) .
+
+buildenv-alpine: build-base
+	docker build \
+	-f docker/alpine.Dockerfile \
+		--build-arg DOCKER_IMAGE_ROOT=$(DOCKER_IMAGE_ROOT) \
+		--build-arg TAG=$(TAG) \
+		--build-arg ALPINE_ARCH=$(ALPINE_ARCH) \
+		--build-arg ALPINE_VER=$(ALPINE_VER) \
+	-t $(DOCKER_IMAGE_ROOT)/buildenv-alpine:$(TAG) .
+
+alpine-rootfs: buildenv-alpine
+	docker run --rm -it \
+		--privileged \
+		-v /cache/apk:/var/cache/apk \
+		-v /cache/artifacts:/artifacts \
+		-e ROOTFS=/out/rootfs \
+		$(DOCKER_IMAGE_ROOT)/buildenv-alpine:$(TAG) \
+		bash -lc '/prepare-chroot.sh && /build-rootfs.sh'