把本机的bash构建到docker镜像里面

最近突发奇想，想把本机的bash放到docker镜像里面，接下来看操作。

获取bash以及依赖

[root@bogon ~]# cat get_lib_info.sh 
#!/bin/bash

# 函数：显示帮助信息
show_help() {
    echo "Usage: $(basename "$0") -h -f <file> -b <output_directory>"
    echo "  -h          Display this help message"
    echo "  -f <file>   Specify the binary file to query"
    echo "  -b <output_directory>  Specify the output directory for the compressed file"
}

# 函数：使用 ldd 和 awk 提取库文件路径
extract_library_paths() {
    local binary_path="$1"
    local paths=()

    # 运行 ldd 命令，过滤并提取库文件路径
    while IFS= read -r line; do
        if [[ "$line" =~ ^/ ]]; then
            paths+=("$line")
        fi
    done < <(ldd "$binary_path" | awk '/=>/ {if ($3 ~ /^\//) print $3}')

    while IFS= read -r line; do
        if [[ "$line" =~ ^/ ]]; then
            paths+=("$line")
        fi
    done < <(ldd "$binary_path" | awk '{print $1}' | grep '^/')

    # 返回路径数组
    echo "${paths[@]}"
}

# 函数：解析符号链接路径
resolve_symlinks() {
    local path="$1"

    # 处理可能存在的符号链接链
    while [[ -L "$path" ]]; do
        target=$(readlink "$path")
        if [[ "${target:0:1}" != "/" ]]; then
            target=$(dirname "$path")/"$target"
        fi
        path="$target"
    done

    # 输出最终的真实路径
    echo "$path"
}

# 主函数：处理二进制文件并生成解析后的路径
process_binary() {
    local binary=""
    local output_directory="$(dirname "$0")"


    # 如果没有提供任何参数，则显示帮助信息
    if [ "$#" -eq 0 ]; then
        show_help
        exit 0
    fi

    # 解析命令行参数
    while getopts "hf:b:" opt; do
        case "$opt" in
            h)  # 显示帮助信息
                show_help
                exit 0
                ;;
            f)  # 指定要查询的文件
                binary="$OPTARG"
                if [ ! -f "$binary" ]; then
                    echo "Error: File '$binary' does not exist." >&2
                    exit 1
                fi
                ;;
            b)  # 指定输出的目录
                output_directory="${OPTARG}"
                ;;
            *)  # 处理未知选项
                echo "Invalid option: -$OPTARG" >&2
                show_help
                exit 1
                ;;
        esac
    done

    # 检查是否提供了二进制文件路径
    if [ -z "$binary" ]; then
        echo "Error: You must specify a binary file with the -f option." >&2
        show_help
        exit 1
    fi

    # 提取库文件路径
    library_paths=($(extract_library_paths "$binary"))

    # 解析符号链接路径
    resolved_paths=()
    for path in "${library_paths[@]}"; do
        resolved_path=$(resolve_symlinks "$path")
        resolved_paths+=("$resolved_path")
    done

    for path in "${library_paths[@]}"; do
        resolved_paths+=("$path")
    done

    # 打印解析后的路径
    # for path in "${resolved_paths[@]}"; do
    #     echo "$path"
    # done

    # 创建解析后路径的 tar 压缩包
    local binary_name=$(basename "$binary")
    tar_filename="${output_directory}/${binary_name##*/}.tar.gz"
    tar zcvf "$tar_filename" "${resolved_paths[@]}"
    echo "已创建压缩包：$tar_filename"
}

# 主程序开始
process_binary "$@"

[root@bogon ~]# chmod +x get_lib_info.sh 
[root@bogon ~]# ./get_lib_info.sh -f /bin/bash
tar: Removing leading `/' from member names
/lib64/libtinfo.so.5.9
/lib64/libdl-2.17.so
/lib64/libc-2.17.so
/lib64/ld-2.17.so
/lib64/libtinfo.so.5
/lib64/libdl.so.2
/lib64/libc.so.6
/lib64/ld-linux-x86-64.so.2
已创建压缩包：./bash.tar.gz

[root@bogon ~]# cp /bin/bash ./

编写Dockerfile

[root@bogon ~]# cat Dockerfile 
FROM scratch

ADD bash.tar.gz /
COPY bash /bin/bash

CMD ["/bin/bash"]

[root@bogon ~]# docker build -t mybash .
[+] Building 0.1s (6/6) FINISHED                                     docker:default
 => [internal] load build definition from Dockerfile                           0.0s
 => => transferring dockerfile: 108B                                           0.0s
 => [internal] load .dockerignore                                              0.0s
 => => transferring context: 2B                                                0.0s
 => [internal] load build context                                              0.0s
 => => transferring context: 1.02MB                                            0.0s
 => [1/2] ADD bash.tar.gz /                                                    0.0s
 => [2/2] COPY bash /bin/bash                                                  0.0s
 => exporting to image                                                         0.0s
 => => exporting layers                                                        0.0s
 => => writing image sha256:86b7d3cc6ffbed8e9c7a921af3d6d671d4692cda8e4fa3924  0.0s
 => => naming to docker.io/library/mybash                                      0.0s

[root@bogon ~]# docker run -it --rm mybash
bash-4.2# exit
exit
[root@bogon ~]#