Add Docker-based CirrOS build environment

Dockerfile

@@ -0,0 +1,94 @@
+# Dockerfile for CirrOS build environment
+#
+# Build image:
+#   docker build -t cirros-builder .
+#
+# Run (--privileged is required for loop mounts inside bin/bundle):
+#   docker run --privileged --rm \
+#     -v "$PWD":/cirros \
+#     -v cirros-dl:/cirros/download \
+#     -v cirros-ccache:/cirros/ccache \
+#     cirros-builder daily
+#
+# Build a specific tagged release:
+#   docker run --privileged --rm \
+#     -v "$PWD":/cirros \
+#     -v cirros-dl:/cirros/download \
+#     -v cirros-ccache:/cirros/ccache \
+#     cirros-builder 0.3.2
+#
+# Build only x86_64:
+#   docker run --privileged --rm \
+#     -e ARCHES=x86_64 \
+#     -v "$PWD":/cirros \
+#     -v cirros-dl:/cirros/download \
+#     -v cirros-ccache:/cirros/ccache \
+#     cirros-builder daily
+
+FROM ubuntu:22.04
+
+LABEL description="CirrOS image build environment (Ubuntu 22.04 / Buildroot 2022.02.4)"
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV TZ=UTC
+ENV USER=root
+
+# ── All build dependencies ────────────────────────────────────────────────────
+# system-setup DEPS + CI extras + tools used implicitly (cpio, kmod, binutils, sudo)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    # system-setup DEPS
+    bc \
+    bison \
+    build-essential \
+    dosfstools \
+    flex \
+    gdisk \
+    gettext \
+    git \
+    grub-common \
+    kpartx \
+    libncurses5-dev \
+    lsb-release \
+    mtools \
+    parallel \
+    python3 \
+    qemu-utils \
+    quilt \
+    rsync \
+    sudo \
+    texinfo \
+    unzip \
+    wget \
+    xz-utils \
+    zstd \
+    # implicit deps (used by bundle/grab-kernels but not listed in system-setup)
+    binutils \
+    cpio \
+    kmod \
+    # CI extras (boot testing + OpenFirmware for ppc64le)
+    cloud-utils \
+    openbios-ppc \
+    qemu-system-arm \
+    qemu-system-misc \
+    qemu-system-ppc \
+    qemu-system-x86 \
+    && rm -rf /var/lib/apt/lists/*
+
+# ── Loop device nodes ─────────────────────────────────────────────────────────
+# Pre-create /dev/loop* nodes for environments where the container /dev is
+# minimal. At runtime --privileged exposes the host kernel's loop subsystem.
+RUN for i in $(seq 0 7); do \
+      [ -e /dev/loop$i ] || mknod /dev/loop$i b 7 $i; \
+    done
+
+WORKDIR /cirros
+
+# Entrypoint that validates the bind-mount and delegates to bin/build-release
+COPY docker-entrypoint.sh /usr/local/bin/cirros-build
+RUN chmod +x /usr/local/bin/cirros-build
+
+# Declare cache-friendly volume mount points
+VOLUME ["/cirros/download", "/cirros/ccache"]
+
+ENTRYPOINT ["/usr/local/bin/cirros-build"]
+CMD ["daily"]

README.md

@@ -56,6 +56,9 @@ the ARCHES variable like:
 * ARCHES=aarch64,x86_64,arm bin/build-release daily
 
 Resulting images will be present in ../build-dYYMMDD/release directory.
+Each architecture gets a bootable `*-minimal.qcow2` image with the traditional
+minimal root filesystem and a `*-full.qcow2` image with the root filesystem
+pre-populated at build time.
 
 
 ## Long, detailed version
@@ -128,7 +131,7 @@ for riscv64,use below version
 We provide simple script to test resulting image. You run it this way:
 
 ```bash
-   $ RELEASE_DIR=$PWD/../build-*/release IMG=$PWD/../build-*/release/cirros-*-x86_64-disk.img bin/test-boot
+   $ RELEASE_DIR=$PWD/../build-*/release IMG=$PWD/../build-*/release/cirros-*-x86_64-full.qcow2 bin/test-boot
 ```      
 
 Note: "RELEASE_DIR" variable is required only for aarch64 and arm images.

bin/build-release

@@ -166,7 +166,7 @@ tstart=${_RET}
 # Stage 1: DOWNLOAD
 logevent "start download" -
 brtgz="buildroot-${BR_VER}.tar.gz"
-dl "http://buildroot.uclibc.org/downloads/$brtgz" "download/$brtgz"
+dl "https://buildroot.org/downloads/$brtgz" "download/$brtgz"
 logevent "end download"
 
 logevent "start unpack" -
@@ -284,7 +284,8 @@ for arch in ${ARCHES}; do
         ln initramfs $p-initrd && ln initramfs $p-initramfs &&
         ln part.img $p-rootfs.img &&
         ln blank.img $p-blank.img &&
-        ln disk.img $p-disk.img &&
+        ln disk-minimal.qcow2 $p-minimal.qcow2 &&
+        ln disk-full.qcow2 $p-full.qcow2 &&
         ln filesys.tar.gz $p-lxc.tar.gz &&
         ln filesys.tar.xz $p-lxc.tar.xz &&
         ln lxd.tar.xz $p-lxd.tar.xz &&
@@ -302,7 +303,8 @@ for arch in ${ARCHES}; do
         ( cd "$OUT/stage/$arch" &&
             tar cvzf - $p-blank.img $p-vmlinuz $p-initrd
         ) > "$OUT/release/$p-uec.tar.gz"
-    cp "$OUT/stage/$arch/$p-disk.img" "$OUT/release/$p-disk.img"
+    cp "$OUT/stage/$arch/$p-minimal.qcow2" "$OUT/release/$p-minimal.qcow2"
+    cp "$OUT/stage/$arch/$p-full.qcow2" "$OUT/release/$p-full.qcow2"
 done
 
 mkdir -p "$OUT/release/buildroot_rootfs"
@@ -323,10 +325,12 @@ msg "output in $OUT/release"
 
 if [ "true" = "${BOOTTEST}" ]; then
     for arch in ${ARCHES}; do
-        img="$OUT/release/cirros-$VER-$arch-disk.img"
-        logevent "start test-boot $arch ${img##*/}" -
-        POWEROFF=true IMG="$img" RELEASE_DIR=$OUT/release test-boot
-        logevent "end test-boot $arch ${img##*/}"
+        for variant in minimal full; do
+            img="$OUT/release/cirros-$VER-$arch-$variant.qcow2"
+            logevent "start test-boot $arch ${img##*/}" -
+            POWEROFF=true IMG="$img" RELEASE_DIR=$OUT/release test-boot
+            logevent "end test-boot $arch ${img##*/}"
+        done
     done
 fi
 

bin/bundle

@@ -55,7 +55,7 @@ getopt_out=$(getopt --name "${0##*/}" \
 topdir=$(cd "${0%/*}/.." && pwd)
 size=${DEF_SIZE}
 FS_LABEL="cirros-rootfs"
-fs_type="ext3"
+fs_type="ext4"
 arch=""
 
 while [ $# -ne 0 ]; do
@@ -99,10 +99,10 @@ mkdir -p "${out_d_in}" && out_d=$(readlink -f "${out_d_in}") &&
     fail "failed to get full path for input"
 
 out_partimg="${out_d}/part.img"
-out_diskimg="${out_d}/disk.img"
+out_minimal_diskimg="${out_d}/disk-minimal.qcow2"
+out_full_diskimg="${out_d}/disk-full.qcow2"
 out_kernel="${out_d}/kernel"
 out_initramfs="${out_d}/initramfs"
-out_diskimg="${out_d}/disk.img"
 out_blankimg="${out_d}/blank.img"
 out_filesys_lxc_gz="${out_d}/filesys.tar.gz"
 out_filesys_lxc_xz="${out_d}/filesys.tar.xz"
@@ -322,47 +322,69 @@ tar -C "$stage_d" -cpf - \
 ( cd "$stage_d" && tar -cpf - * ) > "$filesys_tar" ||
     fail "failed to create filesys_tar"
 
-debug 1 "populating image"
+debug 1 "populating minimal partition image"
 mount -o loop "${out_partimg}" "${mp}" && UMOUNT=${mp} ||
     fail "failed to mount ${out_partimg} loopback"
 
-tar -C "$mp" -xpf - vmlinuz initrd.img boot/ < "$kernel_tar" ||
+tar -C "$mp" -xpf - < "$kernel_tar" ||
     fail "failed to extract kernel_tar"
 cp "$initramfs" "$mp/boot/initrd.img-${kver}"
 
 umount "${mp}" && UMOUNT="" ||
     fail "failed to unmount ${out_partimg}"
 
+full_partimg="$TEMP_D/part.img.full"
+cp "$out_blankimg" "$full_partimg" ||
+    fail "failed to copy full partition image"
+
+debug 1 "populating full partition image"
+mount -o loop "${full_partimg}" "${mp}" && UMOUNT=${mp} ||
+    fail "failed to mount ${full_partimg} loopback"
+
+tar -C "$mp" -xpf - < "$filesys_tar" ||
+    fail "failed to extract filesys_tar"
+cp "$initramfs" "$mp/boot/initrd.img-${kver}"
+
+umount "${mp}" && UMOUNT="" ||
+    fail "failed to unmount ${full_partimg}"
+
 cp "${kernel_d}/${vmlinuz}" "${out_kernel}" ||
     fail "failed to copy kernel to ${out_kernel}"
 
 { [ -z "${out_initramfs}" ] || cp "${initramfs}" "${out_initramfs}"; }  ||
     fail "failed to copy initramfs to ${out_initramfs}"
 
-debug 1 "fixing grub entry in partimg"
-tmp_part="$TEMP_D/part.img.disk"
-cp "$out_partimg" "$tmp_part" &&
-    mount -o loop "$tmp_part" "$mp" && UMOUNT="$mp" ||
-    fail "failed to mount $tmp_part"
-sed -i 's/(hd0)/(hd0,0)/' "$mp/boot/grub/menu.lst" ||
-    fail "failed to edit /boot/grub/menu.lst in image"
-umount "$mp" && UMOUNT="" ||
-    fail "failed to unmount partimg"
-
 case $arch in
     x86_64) grub_options="--grub1 --grub-efi";;
     arm|aarch64|riscv64) grub_options="--grub-efi";;
     ppc*) grub_options="--grub-ieee";;
     *) grub_options=;;
 esac
 
-debug 1 "creating disk image"
-out=$(PATH=$xgrubd:$PATH part2disk $grub_options "$tmp_part" \
-    "$grub_in" "$arch" "$out_diskimg.raw" 2>&1) ||
-    fail "failed to create disk image: $out"
-qemu-img convert -O qcow2 -c "$out_diskimg.raw" "$out_diskimg" ||
-    fail "failed to convert disk image"
-rm -f "$out_diskimg.raw" "$tmp_part"
+write_disk_image() {
+    local partimg="$1" out_diskimg="$2" tmp_part=""
+
+    debug 1 "fixing grub entry in ${partimg}"
+    tmp_part="$TEMP_D/${out_diskimg##*/}.part"
+    cp "$partimg" "$tmp_part" &&
+        mount -o loop "$tmp_part" "$mp" && UMOUNT="$mp" ||
+        fail "failed to mount $tmp_part"
+    sed -i 's/(hd0)/(hd0,0)/' "$mp/boot/grub/menu.lst" ||
+        fail "failed to edit /boot/grub/menu.lst in image"
+    umount "$mp" && UMOUNT="" ||
+        fail "failed to unmount partimg"
+
+    debug 1 "creating disk image ${out_diskimg}"
+    out=$(PATH=$xgrubd:$PATH part2disk $grub_options "$tmp_part" \
+        "$grub_in" "$arch" "$out_diskimg.raw" 2>&1) ||
+        fail "failed to create disk image: $out"
+    qemu-img convert -O qcow2 -c "$out_diskimg.raw" "$out_diskimg" ||
+        fail "failed to convert disk image"
+    rm -f "$out_diskimg.raw" "$tmp_part"
+}
+
+write_disk_image "$out_partimg" "$out_minimal_diskimg"
+write_disk_image "$full_partimg" "$out_full_diskimg"
 
 if [ -n "${SUDO_USER}" ]; then
     u=${SUDO_USER}
@@ -372,7 +394,8 @@ if [ -n "${SUDO_USER}" ]; then
 fi
 
 echo "wrote ${out_partimg}"
-echo "wrote ${out_diskimg}"
+echo "wrote ${out_minimal_diskimg}"
+echo "wrote ${out_full_diskimg}"
 echo "wrote ${out_kernel}"
 echo "wrote ${out_initramfs}"
 echo "wrote ${out_blankimg}"

bin/mirror-dump-sstream-data

@@ -127,7 +127,7 @@ output_for_path() {
     local path=${1#./}
     local size="" md5="" sha256="" pubname=""
     case "$path" in
-        *-uec.tar.gz|*-disk.img|*-rootfs.img|*-lxc.tar.gz|*-lxc.tar.xz) :;;
+        *-uec.tar.gz|*-minimal.qcow2|*-full.qcow2|*-rootfs.img|*-lxc.tar.gz|*-lxc.tar.xz) :;;
         *-lxd.tar.xz) :;;
         *) return;;
     esac

bin/test-boot

@@ -24,12 +24,15 @@ POWEROFF=${POWEROFF:-false}
 
 if [ "$CI_BUILD" = "true" ]; then
     GUESTARCH="${GUESTARCH:-}"
-    IMG=$(find $CI_BUILD_OUT/release/ -name cirros-*-${GUESTARCH}-disk.img)
-    RELEASE_DIR=$CI_BUILD_OUT/release
+    RELEASE_DIR=${RELEASE_DIR:-$CI_BUILD_OUT/release}
+    if [ -z "${IMG:-}" ]; then
+        IMG=$(find "$RELEASE_DIR" -name "cirros-*-${GUESTARCH}-full.qcow2" | head -n1)
+    fi
 else
     GUESTARCH="${GUESTARCH:-$(echo $(basename $IMG)| cut -d'-' -f3)}"
 fi
 
+GUESTARCH="${GUESTARCH:-$(echo $(basename $IMG)| cut -d'-' -f3)}"
 VER=$(echo $(basename $IMG)| cut -d'-' -f2)
 
 echo '{"instance-id": "9068aef2-213e-4e43-830f-accdbadde897"}' > meta-data

docker-entrypoint.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# docker-entrypoint.sh — run inside the cirros-builder container
+set -euo pipefail
+
+# Ensure loop device support (requires --privileged)
+modprobe loop max_loop=16 2>/dev/null || true
+
+# Expect the cirros source tree to be bind-mounted at /cirros
+cd /cirros
+[ -f bin/build-release ] || {
+    echo "ERROR: /cirros does not look like a cirros source tree."
+    echo "  Bind-mount the repo: -v \$PWD:/cirros"
+    exit 1
+}
+
+VERSION="${1:-daily}"
+shift || true
+
+export CI_BUILD="${CI_BUILD:-true}"
+export CI_BUILD_OUT="${CI_BUILD_OUT:-build-ci/}"
+
+echo "==> Building CirrOS version: ${VERSION}"
+echo "==> Architectures: ${ARCHES:-x86_64 arm aarch64 ppc64le riscv64}"
+
+exec bin/build-release "${VERSION}" "$@"