Add Container Management Script

1 files changed, 100 insertions, 0 deletions

diff --git a/debian-container.sh b/debian-container.sh
new file mode 100644
index 0000000..be2b1f5
--- /dev/null
+++ b/debian-container.sh
@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+# Debian 构建容器
+set -Eeuo pipefail
+
+SCRIPT=$(readlink -f -- "${BASH_SOURCE[0]}")
+IMAGE=$PWD/rootfs.ext4
+ROOT=$PWD/debian-root/
+ACTION=${1:-}
+
+if [[ ${EUID} -ne 0 ]]; then
+  echo '请使用 sudo 执行本脚本。' >&2
+  exit 1
+fi
+
+cleanup_mounts() {
+  umount "$ROOT/dev/pts" 2>/dev/null || true
+  umount "$ROOT/dev" 2>/dev/null || true
+  umount "$ROOT/proc" 2>/dev/null || true
+  umount "$ROOT" 2>/dev/null || true
+}
+
+mount_root() {
+  mkdir -p "$ROOT"
+  mount -o loop "$IMAGE" "$ROOT"
+  mkdir -p "$ROOT/proc" "$ROOT/dev"
+}
+
+mount_virtual_filesystems() {
+  mount -t proc -o ro,nosuid,nodev,noexec proc "$ROOT/proc"
+  mount -t tmpfs -o mode=0755,nosuid tmpfs "$ROOT/dev"
+  mknod -m 0666 "$ROOT/dev/null" c 1 3
+  mknod -m 0666 "$ROOT/dev/zero" c 1 5
+  mknod -m 0666 "$ROOT/dev/random" c 1 8
+  mknod -m 0666 "$ROOT/dev/urandom" c 1 9
+  mknod -m 0666 "$ROOT/dev/tty" c 5 0
+  mkdir -p "$ROOT/dev/pts"
+  mount -t devpts -o newinstance,ptmxmode=0666,mode=0620 devpts "$ROOT/dev/pts"
+  ln -s pts/ptmx "$ROOT/dev/ptmx"
+}
+
+# 防止多个会话同时读写同一 ext4 镜像。
+case "$ACTION" in
+  init|enter|delete)
+    mkdir -p /run/lock
+    exec 9>/run/lock/debian-container.lock
+    flock -n 9 || { echo 'Debian 容器已经在运行或正在初始化。' >&2; exit 1; }
+    ;;
+esac
+
+case "$ACTION" in
+  init)
+    for tool in debootstrap unshare mkfs.ext4 mount chroot setpriv flock; do
+      command -v "$tool" >/dev/null || { echo "缺少工具：$tool" >&2; exit 1; }
+    done
+    if [[ -e "$IMAGE" ]]; then
+      echo "镜像已存在：$IMAGE。请使用 enter 进入，避免覆盖容器数据。" >&2
+      exit 1
+    fi
+    mkdir -p "$(dirname "$IMAGE")" "$ROOT"
+    truncate -s 3G "$IMAGE"
+    mkfs.ext4 -F -q -L DEBIAN_CONTAINER "$IMAGE"
+    unshare --mount --propagation private -- bash "$SCRIPT" _init
+    echo '初始化完成。执行 sudo bash debian-container.sh enter 进入容器。'
+    ;;
+  _init)
+    mount_root
+    trap cleanup_mounts EXIT
+    debootstrap --variant=minbase stable "$ROOT" http://deb.debian.org/debian
+    rm -f "$ROOT/etc/resolv.conf"
+    cp -L /etc/resolv.conf "$ROOT/etc/resolv.conf"
+    mount_virtual_filesystems
+    chroot "$ROOT" /usr/bin/env DEBIAN_FRONTEND=noninteractive /usr/bin/apt-get update
+    chroot "$ROOT" /usr/bin/env DEBIAN_FRONTEND=noninteractive /usr/bin/apt-get install -y passwd util-linux vim-tiny e2fsprogs
+    echo debian-container > "$ROOT/etc/hostname"
+    ;;
+  enter)
+    [[ -f "$IMAGE" ]] || { echo '没有找到镜像，请先运行 init。' >&2; exit 1; }
+    # 单独创建网络命名空间，暂时没有联网功能。
+    unshare --mount --uts --ipc --pid --net --fork --propagation private -- bash "$SCRIPT" _enter
+    ;;
+  _enter)
+    mount_root
+    trap cleanup_mounts EXIT
+    mount_virtual_filesystems
+    hostname debian-container
+    echo '已进入独立的 Debian 实验环境；输入 exit 可退出。'
+    # 完成挂载后撤销一些宿主级危险权限，保留 CAP_LINUX_IMMUTABLE。
+    setpriv --bounding-set=-sys_admin,-net_admin,-net_raw,-sys_module,-sys_boot,-sys_time,-sys_rawio,-sys_ptrace,-syslog -- \
+      chroot "$ROOT" /bin/bash -l
+    ;;
+  delete)
+    [[ -f "$IMAGE" ]] || { echo 'Debian 镜像已不存在。'; exit 0; }
+    rm -- "$IMAGE"
+    echo 'Debian 镜像已删除。'
+    ;;
+  *)
+    echo "用法：sudo bash $0 init|enter|delete" >&2
+    exit 2
+    ;;
+esac