Question

我有一个来自镜像的Dockerfile。我想修改它并添加一些文件操作，这些操作将相对于与FROM图像所给定的WORKDIR不同。因此，我想在修改WORKDIR之前将WORKDIR保存到一个变量，并在命令结束后从该变量恢复WORKDIR。该怎么做？

想要的结果：

Dockerfile伪代码：

FROM centos:7
some original commands
some original commands
...
var=WORKDIR #save WORKDIR <== how to do that?

WORDIR /my/path/
my commands
my commands

...
WORKDIR = var # restore path that was before <== how to do that?

Answer 1

如果您尝试从基本映像中保留WORKDIR，则不可能

WORKDIR仅在您在同一dockerfile中进行设置时才具有值。

如果您尝试为不同的命令使用不同的工作目录：

Dockerfile伪代码：

FROM centos:7
some original commands
some original commands
...
ARG PATH1=/path1
ARG PATH2=/path1

my commands
my commands

WORKDIR PATH1
my commands
my commands

WORKDIR PATH2
my commands
my commands

WORKDIR PATH1
my commands
my commands

...
WORKDIR PATH1 # restore path that was before <== how to do that?

Answer 2

添加到WSMathias9的答案中：

除非WORKDIR被您使用的基本图像更改，否则默认情况下始终为/，您可以在完成以下操作后将其设置为/这是centos图片的默认图片

但是，如果您使用WORKDIR代替cd，只需在cd中使用RUN

而不是例如：

FROM centos:7

WORKDIR /folder
RUN mycommand

要做：

FROM centos:7

RUN cd /folder && mycommand

Answer 3

您可以创建环境变量。

ENV WORKDIR=/my/path/
WORDIR $WORKDIR

Docker如何在Dockerfile中保存和恢复WORKDIR？

3 个答案: