exec表单中的Docker运行命令不工作_Docker_Alpine

exec表单中的Docker运行命令不工作

docker

exec表单中的Docker运行命令不工作,docker,alpine,Docker,Alpine,我正在建立一个基于阿尔卑斯山的码头工人形象 FROM alpine RUN apk update \ && apk add lighttpd \ && rm -rf /var/cache/apk/* ENV COLOR red COPY ./index.html /var/www/localhost/htdocs RUN /bin/ash -c 'echo abcd' #working RUN /bin/ash -c "echo

我正在建立一个基于阿尔卑斯山的码头工人形象

FROM alpine

RUN apk update \
    && apk add lighttpd \
    && rm -rf /var/cache/apk/*

ENV COLOR red

COPY ./index.html /var/www/localhost/htdocs

RUN /bin/ash -c 'echo abcd'
#working
RUN /bin/ash -c "echo $COLOR; sed -i -e 's/red/\$COLOR/g' /var/www/localhost/htdocs/index.html; cat /var/www/localhost/htdocs/index.html;"
#not working
# RUN ["sh", "-c", "echo $COLOR; sed -i -e 's/red/\$COLOR/g' /var/www/localhost/htdocs/index.html; cat /var/www/localhost/htdocs/index.html;"]

CMD ["lighttpd","-D","-f","/etc/lighttpd/lighttpd.conf"]

当我以shell形式运行时，它工作得很好，但当我以exec形式运行时，它提供了

/bin/sh:[sh，：未找到

我试过使用

bin/sh

，

sh

，

bin/ash

，

ash

。所有这些都是相同的错误。

我已经使用Docker好几年了，直到你提出问题，我才知道有shell | exec表单用于

RUN

；-）

问题在于，您的命令包含环境变量（

$COLOR

），并且没有使用

exec

表单替代|求值

见：

“与shell表单不同，exec表单不调用命令shell。这意味着正常的shell处理不会发生”

我已经使用Docker好几年了，我不知道（直到你提出问题）有用于运行

的shell | exec表单
问题在于，您的命令包含环境变量（$COLOR
），并且没有使用exec
表单替代|求值
见：

“与shell表单不同，exec表单不调用命令shell。这意味着正常的shell处理不会发生”
shell负责展开变量，但只展开双引号中的变量
您的错误源于\
之前的错误$COLOR
，事实上，从shell获取值对您没有任何意义，正确的方法是下一步：
RUN ["sh", "-c", "echo $COLOR; sed -i -e \"s/red/$COLOR/g\" /var/www/localhost/htdocs/index.html; cat /var/www/localhost/htdocs/index.html;"]

一个显示效果的最小示例，仅供参考：
Dockerfile:
FROM alpine
ENV COLOR rednew
RUN echo "red" > /tmp/index.html
RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]

$ docker build -t abc:1 . --no-cache                                                                                              
Sending build context to Docker daemon  5.632kB
Step 1/4 : FROM alpine
 ---> 28f6e2705743
Step 2/4 : ENV COLOR rednew
 ---> Running in 05c43146fab0
Removing intermediate container 05c43146fab0
 ---> 28ea1434e626
Step 3/4 : RUN echo "red" > /tmp/index.html
 ---> Running in 2c8fbbc5fd10
Removing intermediate container 2c8fbbc5fd10
 ---> f884892ad8c4
Step 4/4 : RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]
 ---> Running in 6930b3d03438
rednew
Removing intermediate container 6930b3d03438
 ---> b770475672cc
Successfully built b770475672cc
Successfully tagged abc:1

结果：
FROM alpine
ENV COLOR rednew
RUN echo "red" > /tmp/index.html
RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]

$ docker build -t abc:1 . --no-cache                                                                                              
Sending build context to Docker daemon  5.632kB
Step 1/4 : FROM alpine
 ---> 28f6e2705743
Step 2/4 : ENV COLOR rednew
 ---> Running in 05c43146fab0
Removing intermediate container 05c43146fab0
 ---> 28ea1434e626
Step 3/4 : RUN echo "red" > /tmp/index.html
 ---> Running in 2c8fbbc5fd10
Removing intermediate container 2c8fbbc5fd10
 ---> f884892ad8c4
Step 4/4 : RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]
 ---> Running in 6930b3d03438
rednew
Removing intermediate container 6930b3d03438
 ---> b770475672cc
Successfully built b770475672cc
Successfully tagged abc:1

Shell负责展开变量，但只展开双引号中的变量
您的错误源于\
之前的错误$COLOR
，事实上，从shell获取值对您没有任何意义，正确的方法是下一步：
RUN ["sh", "-c", "echo $COLOR; sed -i -e \"s/red/$COLOR/g\" /var/www/localhost/htdocs/index.html; cat /var/www/localhost/htdocs/index.html;"]

一个显示效果的最小示例，仅供参考：
Dockerfile:
FROM alpine
ENV COLOR rednew
RUN echo "red" > /tmp/index.html
RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]

$ docker build -t abc:1 . --no-cache                                                                                              
Sending build context to Docker daemon  5.632kB
Step 1/4 : FROM alpine
 ---> 28f6e2705743
Step 2/4 : ENV COLOR rednew
 ---> Running in 05c43146fab0
Removing intermediate container 05c43146fab0
 ---> 28ea1434e626
Step 3/4 : RUN echo "red" > /tmp/index.html
 ---> Running in 2c8fbbc5fd10
Removing intermediate container 2c8fbbc5fd10
 ---> f884892ad8c4
Step 4/4 : RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]
 ---> Running in 6930b3d03438
rednew
Removing intermediate container 6930b3d03438
 ---> b770475672cc
Successfully built b770475672cc
Successfully tagged abc:1

结果：
FROM alpine
ENV COLOR rednew
RUN echo "red" > /tmp/index.html
RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]

$ docker build -t abc:1 . --no-cache                                                                                              
Sending build context to Docker daemon  5.632kB
Step 1/4 : FROM alpine
 ---> 28f6e2705743
Step 2/4 : ENV COLOR rednew
 ---> Running in 05c43146fab0
Removing intermediate container 05c43146fab0
 ---> 28ea1434e626
Step 3/4 : RUN echo "red" > /tmp/index.html
 ---> Running in 2c8fbbc5fd10
Removing intermediate container 2c8fbbc5fd10
 ---> f884892ad8c4
Step 4/4 : RUN ["sh", "-c", "sed -i -e \"s/red/$COLOR/g\" /tmp/index.html; cat /tmp/index.html;"]
 ---> Running in 6930b3d03438
rednew
Removing intermediate container 6930b3d03438
 ---> b770475672cc
Successfully built b770475672cc
Successfully tagged abc:1

你完全正确..谢谢！这个错误有点误导..当它说/bin/sh:[sh，：not found
时，我只是关注第一个参数。你完全正确..谢谢！这个错误有点误导..我只是关注第一个参数，当它说/bin/sh:[sh，：not found
。