docker - Docker镜像构建最终以悬挂的镜像结束

Question

我的Dockerfile:

FROM ubuntu:latest

ENV STAR_VERSION=2.7.3a
ENV DEBIAN_FRONTEND=noninteractive

RUN apt-get update \
        && apt-get install -y git-all \
        && apt-get install -y --no-install-recommends apt-utils \
        && apt-get install -y --no-install-recommends build-essential \
        && apt-get install -y make \
        && apt-get install -y libz.dev \
        && echo "downloading ${STAR_VERSION}"

WORKDIR /mnt/d/github/Docker/STAR_2.7.3a/

RUN git clone https://github.com/alexdobin/STAR.git \
        && cd STAR/source \
        && echo "making STAR ${STAR_VERSION}" \
        && make STAR

CMD ["STAR", "--version"]

建立图片:

docker image build .

它显示它已成功构建(尽管有一些警告)，但是当我检查它时

$ docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
<none>              <none>              e57297dc089d        29 minutes ago      1.41GB
<none>              <none>              8c4d6c6be0d2        About an hour ago   915MB
<none>              <none>              a2625623ebb7        2 hours ago         754MB
$ docker image ls --filter dangling=true
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
<none>              <none>              e57297dc089d        30 minutes ago      1.41GB
<none>              <none>              8c4d6c6be0d2        About an hour ago   915MB
<none>              <none>              a2625623ebb7        2 hours ago         754MB

为什么它们都单薄而没有标签？

Answer 1

默认情况下，您从Dockerfile生成的镜像是未加标签的，并且是未修饰的。

您需要将repo:tag作为选项传递给build命令以对其进行标记。

docker image build --tag some/repo:tag . 

从文档中:

--tag , -t      Name and optionally a tag in the ‘name:tag’ format

资料来源: https://docs.docker.com/engine/reference/commandline/image_build/

请注意:带有未标记图像的情况也可能发生，如果您使用相同标签重新标记了另一个图像，也就是说，从现有图像中窃取了该标签，而使旧图像未标记。

This will display untagged images that are the leaves of the images tree (not intermediary layers). These images occur when a new build of an image takes the repo:tag away from the image ID, leaving it as <none>:<none> or untagged. A warning will be issued if trying to remove an image when a container is presently using it. By having this flag it allows for batch cleanup.

资料来源: https://docs.docker.com/engine/reference/commandline/images/#filtering