每个 Dockerfile 运行调用中的源代码

Question

我有一个 Docker 文件，我发现自己经常需要调用 source /opt/ros/noetic/setup.bash.

例如：

RUN source /opt/ros/noetic/setup.bash \
    && SOME_COMMAND

RUN source /opt/ros/noetic/setup.bash \
    && SOME_OTHER_COMMAND

是否有一种方法可以在 Docker 文件中的每个 RUN 调用中进行初始化？

已尝试添加到 ~/.bash_profile 和 Docker 的 ENV 命令，但没有成功。

Answer 1

TL;DR: 通过将 .sh 脚本复制到 /etc/profile.d/ 并使用 SHELL Dockerfile 命令来实现您想要的是可行的调整默认 shell.

详情：

首先，考虑以下示例脚本 setup.sh:

#!/bin/sh
echo "# setup.sh"
ENV_VAR="some value"
some_fun() {
    echo "## some_fun"
}

然后，可以注意到 bash 提供了 --login CLI 选项：

When Bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

When an interactive login shell exits, or a non-interactive login shell executes the exit builtin command, Bash reads and executes commands from the file ~/.bash_logout, if it exists.

− https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Bash-Startup-Files

此外，您可以利用大多数发行版按以下方式读取的 /etc/profile.d 文件夹，而不是在 /etc/profile 中附加 setup.sh 代码：

$ docker run --rm -i debian:10 cat /etc/profile | tail -n 9

if [ -d /etc/profile.d ]; then
  for i in /etc/profile.d/*.sh; do
    if [ -r $i ]; then
      . $i
    fi
  done
  unset i
fi

请特别注意 .sh 扩展名是强制性的，因此上面最小工作示例的命名是：setup.sh（不是 setup.bash）。

最后，可以依靠 SHELL command 替换 RUN 使用的默认 shell（代替 ["/bin/sh", "-c"]）来合并 [= bash.

的 18=] 选项

具体来说，您可以这样表达您的 Dockerfile：

FROM debian:10

# WORKDIR /opt/ros/noetic
# COPY setup.sh .
# RUN . /opt/ros/noetic/setup.sh && echo "ENV_VAR=$ENV_VAR"

# empty var here
RUN echo "ENV_VAR=$ENV_VAR"

# enable the extra shell init code
COPY setup.sh /etc/profile.d/

SHELL ["/bin/bash", "--login", "-c"]

# nonempty var and function
RUN echo "ENV_VAR=$ENV_VAR" && some_fun

# DISABLE the extra shell init code!
RUN rm /etc/profile.d/setup.sh

# empty var here
RUN echo "ENV_VAR=$ENV_VAR"

结果：

$ docker build -t test .
Sending build context to Docker daemon  6.144kB
Step 1/7 : FROM debian:10
 ---> ef05c61d5112
Step 2/7 : RUN echo "ENV_VAR=$ENV_VAR"
 ---> Running in 87b5c589ec60
ENV_VAR=
Removing intermediate container 87b5c589ec60
 ---> 6fdb70be76f9
Step 3/7 : COPY setup.sh /etc/profile.d/
 ---> e6aab4ebf9ef
Step 4/7 : SHELL ["/bin/bash", "--login", "-c"]
 ---> Running in d73b0d13df23
Removing intermediate container d73b0d13df23
 ---> ccbe789dc36d
Step 5/7 : RUN echo "ENV_VAR=$ENV_VAR" && some_fun
 ---> Running in 42fd1ae14c17
# setup.sh
ENV_VAR=some value
## some_fun
Removing intermediate container 42fd1ae14c17
 ---> de74831896a4
Step 6/7 : RUN rm /etc/profile.d/setup.sh
 ---> Running in bdd969a63def
# setup.sh
Removing intermediate container bdd969a63def
 ---> 5453be3271e5
Step 7/7 : RUN echo "ENV_VAR=$ENV_VAR"
 ---> Running in 0712cea427f1
ENV_VAR=
Removing intermediate container 0712cea427f1
 ---> 216a421f5659
Successfully built 216a421f5659
Successfully tagged test:latest

每个 Dockerfile 运行调用中的源代码

source in every Dockerfile RUN call

bash

ubuntu

ros

docker

dockerfile

详情：

每个 Dockerfile 运行 调用中的源代码

source in every Dockerfile RUN call

bash

ubuntu

ros

docker

dockerfile

详情：

每个 Dockerfile 运行调用中的源代码