有没有办法在构建 Docker 映像时抑制“更新替代：警告：跳过创建”警告？

Question

构建这个Dockerfile：

FROM ubuntu:19.10

ENV DEBIAN_FRONTEND noninteractive

RUN apt-get update 
RUN apt-get install -y locales apt-utils
RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
    dpkg-reconfigure locales && \
    update-locale LANG=en_US.UTF-8

ENV LANG en_US.UTF-8 

RUN apt-get install --no-install-recommends -y vim 

CMD /bin/bash

输出一些警告信息：

update-alternatives: warning: skip creation of /usr/share/man/da/man1/vi.1.gz because associated file /usr/share/man/da/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/de/man1/vi.1.gz because associated file /usr/share/man/de/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/fr/man1/vi.1.gz because associated file /usr/share/man/fr/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/it/man1/vi.1.gz because associated file /usr/share/man/it/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ja/man1/vi.1.gz because associated file /usr/share/man/ja/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/pl/man1/vi.1.gz because associated file /usr/share/man/pl/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ru/man1/vi.1.gz because associated file /usr/share/man/ru/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/man1/vi.1.gz because associated file /usr/share/man/man1/vim.1.gz (of link group vi) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/da/man1/view.1.gz because associated file /usr/share/man/da/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/de/man1/view.1.gz because associated file /usr/share/man/de/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/fr/man1/view.1.gz because associated file /usr/share/man/fr/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/it/man1/view.1.gz because associated file /usr/share/man/it/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ja/man1/view.1.gz because associated file /usr/share/man/ja/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/pl/man1/view.1.gz because associated file /usr/share/man/pl/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ru/man1/view.1.gz because associated file /usr/share/man/ru/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/man1/view.1.gz because associated file /usr/share/man/man1/vim.1.gz (of link group view) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/da/man1/ex.1.gz because associated file /usr/share/man/da/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/de/man1/ex.1.gz because associated file /usr/share/man/de/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/fr/man1/ex.1.gz because associated file /usr/share/man/fr/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/it/man1/ex.1.gz because associated file /usr/share/man/it/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ja/man1/ex.1.gz because associated file /usr/share/man/ja/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/pl/man1/ex.1.gz because associated file /usr/share/man/pl/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ru/man1/ex.1.gz because associated file /usr/share/man/ru/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/man1/ex.1.gz because associated file /usr/share/man/man1/vim.1.gz (of link group ex) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/da/man1/editor.1.gz because associated file /usr/share/man/da/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/de/man1/editor.1.gz because associated file /usr/share/man/de/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/fr/man1/editor.1.gz because associated file /usr/share/man/fr/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/it/man1/editor.1.gz because associated file /usr/share/man/it/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ja/man1/editor.1.gz because associated file /usr/share/man/ja/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/pl/man1/editor.1.gz because associated file /usr/share/man/pl/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/ru/man1/editor.1.gz because associated file /usr/share/man/ru/man1/vim.1.gz (of link group editor) doesn't exist
update-alternatives: warning: skip creation of /usr/share/man/man1/editor.1.gz because associated file /usr/share/man/man1/vim.1.gz (of link group editor) doesn't exist

1. 最好不要安装手册页
2. 另外我不想要 de、fr、it、ja、pl、ru 语言的手册页（如果 1. 不可能，我只需要 en 手册页）

有没有办法阻止 apt 安装这些手册页，然后打印这些警告，因为它找不到相关文件？

Answer 1

如果您只是想节省磁盘空间和/或网络带宽，试试这个：

echo 'path-exclude /usr/share/doc/*' >/etc/dpkg/dpkg.cfg.d/docker-minimal && \ 
echo 'path-exclude /usr/share/man/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-exclude /usr/share/groff/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-exclude /usr/share/info/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-exclude /usr/share/lintian/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-exclude /usr/share/linda/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-exclude /usr/share/locale/*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal && \
echo 'path-include /usr/share/locale/en*' >>/etc/dpkg/dpkg.cfg.d/docker-minimal

只要您尝试安装一些 APT 软件包，就不会将手册页保存到磁盘。 警告仍然存在，但手册页不存在。

这里的问题是某些包从 .deb 包的 postinst 部分调用 update-alternatives 二进制文件。见https://manpages.debian.org/buster/dpkg/update-alternatives.1.en.html。 不知道你是否也可以要求 DPKG 根本不执行 postinst 部分，但这听起来不太好！ 您也可以为 update-alternatives 编写一个小包装器以抑制警告，但这听起来很愚蠢。

Answer 2

请使用以下 Dockerfile 构建您的图像。

FROM ubuntu:19.10
ENV DEBIAN_FRONTEND noninteractive
RUN apt-get update
RUN apt-get install -y locales apt-utils
RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
    dpkg-reconfigure locales && \
    update-locale LANG=en_US.UTF-8
ENV LANG en_US.UTF-8
RUN apt-get -qq install --no-install-recommends  vim > /dev/null
CMD /bin/bash