在Dockerfile中，如何更新PATH环境变量？

古城微笑少年丶 2023-03-04 06:34 17阅读 0赞

本文翻译自：[In a Dockerfile, How to update PATH environment variable?][In a Dockerfile_ How to update PATH environment variable]

*I have a dockerfile that download and builds GTK from source, but the following line is not updating my image's environment variable:* **我有一个从源代码下载并构建GTK的dockerfile，但是以下行未更新映像的环境变量：**

RUN PATH="/opt/gtk/bin:$PATH"
    RUN export PATH

*I read that that I should be using ENV to set environment values, but the following instruction doesn't seem to work either:* **我读到我应该使用ENV来设置环境值，但是以下指令似乎也不起作用：**

`ENV PATH /opt/gtk/bin:$PATH`

*This is my entire Dockerfile:* **这是我的整个Dockerfile：**

FROM ubuntu
    RUN apt-get update
    RUN apt-get install -y golang gcc make wget git libxml2-utils libwebkit2gtk-3.0-dev libcairo2 libcairo2-dev libcairo-gobject2 shared-mime-info libgdk-pixbuf2.0-* libglib2-* libatk1.0-* libpango1.0-* xserver-xorg xvfb
    
    # Downloading GTKcd
    RUN wget http://ftp.gnome.org/pub/gnome/sources/gtk+/3.12/gtk+-3.12.2.tar.xz
    RUN tar xf gtk+-3.12.2.tar.xz
    RUN cd gtk+-3.12.2
    
    # Setting environment variables before running configure
    RUN CPPFLAGS="-I/opt/gtk/include"
    RUN LDFLAGS="-L/opt/gtk/lib"
    RUN PKG_CONFIG_PATH="/opt/gtk/lib/pkgconfig"
    RUN export CPPFLAGS LDFLAGS PKG_CONFIG_PATH
    RUN ./configure --prefix=/opt/gtk
    RUN make
    RUN make install
    
    # running ldconfig after make install so that the newly installed libraries are found.
    RUN ldconfig
    
    # Setting the LD_LIBRARY_PATH environment variable so the systems dynamic linker can find the newly installed libraries.
    RUN LD_LIBRARY_PATH="/opt/gtk/lib"
    
    # Updating PATH environment program so that utility binaries installed by the various libraries will be found.
    RUN PATH="/opt/gtk/bin:$PATH"
    RUN export LD_LIBRARY_PATH PATH
    
    # Collecting garbage
    RUN rm -rf gtk+-3.12.2.tar.xz
    
    # creating go code root
    RUN mkdir gocode
    RUN mkdir gocode/src
    RUN mkdir gocode/bin
    RUN mkdir gocode/pkg
    
    # Setting the GOROOT and GOPATH enviornment variables, any commands created are automatically added to PATH
    RUN GOROOT=/usr/lib/go
    RUN GOPATH=/root/gocode
    RUN PATH=$GOPATH/bin:$PATH
    RUN export GOROOT GOPATH PATH

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### \#1楼 ###

参考：[https://stackoom.com/question/1PGhK/在Dockerfile中-如何更新PATH环境变量][https_stackoom.com_question_1PGhK_Dockerfile_-_PATH]

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### \#2楼 ###

*Although the answer that Gunter posted was correct, it is not different than what I already had posted.* **尽管Gunter发布的答案是正确的，但与我已经发布的答案没有什么不同。** *The problem was not the `ENV` directive, but the subsequent instruction `RUN export $PATH`* **问题不在于`ENV`指令，而是随后的指令`RUN export $PATH`**

*There's no need to export the environment variables, once you have declared them via `ENV` in your Dockerfile.* **一旦在Dockerfile中通过`ENV`声明了环境变量，就无需导出环境变量。**

*As soon as the `RUN export ...` lines were removed, my image was built successfully* **删除`RUN export ...`行后，便成功构建了我的映像**

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### \#3楼 ###

您可以在`Dockerfile`使用[环境替换][Link 1] ，如下所示：

ENV PATH="/opt/gtk/bin:${PATH}"

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### \#4楼 ###

*This is discouraged (if you want to create/distribute a clean Docker image), since the `PATH` variable is set by `/etc/profile` script, the value can be overridden.* **不建议这样做（如果要创建/分发干净的Docker映像），因为`PATH`变量是由`/etc/profile`脚本设置的，因此可以覆盖该值。**

*`head /etc/profile` :* **`head /etc/profile` ：**

if [ "`id -u`" -eq 0 ]; then
      PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
    else
      PATH="/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games"
    fi
    export PATH

*At the end of the Dockerfile, you could add:* **在Dockerfile的末尾，您可以添加：**

RUN echo "export PATH=$PATH" > /etc/environment

*So PATH is set for all users.* **因此，为所有用户设置了PATH。**

[In a Dockerfile_ How to update PATH environment variable]: https://oldbug.net/q/1PGhK/In-a-Dockerfile-How-to-update-PATH-environment-variable
[https_stackoom.com_question_1PGhK_Dockerfile_-_PATH]: https://stackoom.com/question/1PGhK/%E5%9C%A8Dockerfile%E4%B8%AD-%E5%A6%82%E4%BD%95%E6%9B%B4%E6%96%B0PATH%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F
[Link 1]: https://docs.docker.com/engine/reference/builder/#environment-replacement