如何使用Docker的COPY / ADD指令将单个文件复制到图像中 [英] How to use Docker's COPY/ADD instructions to copy a single file to an image
问题描述
我使用的Docker文件是如下:
FROM debian:latest
RUN mkdir -p / usr / src / app
WORKDIR / usr / src / app
COPY test.txt / usr / src / app
test.txt文件是一个简单的ASCII文本文件,如下所示:
$ cat test.txt
这是一个测试
但是,当我构建此图像时,我会收到一个图像,指出目标路径不是目录。
$ docker build。
将构建上下文发送到Docker守护程序4.608 kB
将构建上下文发送到Docker守护程序
步骤0:FROM debian:latest
---> 9a61b6b1315e
步骤1:运行mkdir -p / usr / src / app
--->使用缓存
---> 86bd44a8776e
步骤2:WORKDIR / usr / src / app
--->使用缓存
---> ed6771adc681
步骤3:ADD test.txt / usr / src / app
stat /var/lib/docker/devicemapper/mnt/ee5b9b7029f2adf27d332cbb0d98d6ad9927629a7569fd2d9574cb767b23547b/rootfs/usr/src/app/test.txt:不是目录
我已尝试使用Docker版本,基本映像和发行版的多种组合,并安装了docker。我也尝试使用ADD而不是COPY,但结果是一样的。
我正在CentOS 7上尝试安装以下Docker版本:
客户端版本:1.7.1
客户端API版本:1.19
Go版本(客户端):go1.4.2
Git commit(client):786b29d
操作系统/ Arch(客户端):linux / amd64
服务器版本:1.7.1
服务器API版本:1.19
转到版本):go1.4.2
Git commit(server):786b29d
操作系统/ Arch(服务器):linux / amd64
我注意到的是我可以复制一个目录,而不是一个文件。例如,如果我在构建上下文根目录中创建一个test目录,并将test.txt放在测试目录中,那么我可以成功复制目录:
FROM debian:最新
运行mkdir -p / usr / src / app
WORKDIR / usr / src / app
COPY test / usr / src / app $ b请注意,在上面的Docker文件中,我复制整个./test目录,而不是只有./test.txt。
Docker文档对于COPY指令,有以下示例用例类似于我正在尝试的操作:
COPY可以有人指出我做错了什么吗?????txt / mydir /
<如何复制单个文件?
解决方案
-
如果< src>
是任何其他类型的文件,它将与其元数据一起单独复制。在这种情况下,如果< dest>
以尾部斜线 /
结束,则将被视为目录, < src>
的内容将以< dest> / base(< src>)
/ p>
-
如果< dest>
不以尾部斜杠结尾,则会被视为常规文件并且< src>
的内容将写在< dest>
。
因此,您必须编写 COPY test.txt / usr / src / app /
,尾随 /
。
I am trying to copy a single file from the root of the build context into a newly created directory in a docker image.
The Dockerfile that I am using is as follows:
FROM debian:latest
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY test.txt /usr/src/app
The test.txt file is a simple ASCII text file as follows:
$ cat test.txt
This is a test
However, when I build this image I get an image stating that the destination path is not a directory.
$ docker build .
Sending build context to Docker daemon 4.608 kB
Sending build context to Docker daemon
Step 0 : FROM debian:latest
---> 9a61b6b1315e
Step 1 : RUN mkdir -p /usr/src/app
---> Using cache
---> 86bd44a8776e
Step 2 : WORKDIR /usr/src/app
---> Using cache
---> ed6771adc681
Step 3 : ADD test.txt /usr/src/app
stat /var/lib/docker/devicemapper/mnt/ee5b9b7029f2adf27d332cbb0d98d6ad9927629a7569fd2d9574cb767b23547b/rootfs/usr/src/app/test.txt: not a directory
I have tried using multiple combinations of docker versions, base images, and distributions with docker installed. I have also tried using ADD instead of COPY but the result is the same.
I am currently trying this on CentOS 7 with the following docker version installed:
Client version: 1.7.1
Client API version: 1.19
Go version (client): go1.4.2
Git commit (client): 786b29d
OS/Arch (client): linux/amd64
Server version: 1.7.1
Server API version: 1.19
Go version (server): go1.4.2
Git commit (server): 786b29d
OS/Arch (server): linux/amd64
What I have noticed is that I can copy a directory, but not a file. For example, if I create a "test" directory in the build context root and put test.txt inside the test directory then I can copy the directory successfully:
FROM debian:latest
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY test /usr/src/app
Note that in the above Dockerfile I copy the entire ./test directory rather than just ./test.txt. This build successfully.
The Docker documentation has the following sample use case for the COPY instruction which is similar to what I am trying to do:
COPY hom?.txt /mydir/
Can anyone point out what I am doing wrong? How can I go about copying a single file?
解决方案 As stated in the Dockerfile documentation:
If <src>
is any other kind of file, it is copied individually along with its metadata. In this case, if <dest>
ends with a trailing slash /
, it will be considered a directory and the contents of <src>
will be written at <dest>/base(<src>)
.
If <dest>
does not end with a trailing slash, it will be considered a regular file and the contents of <src>
will be written at <dest>
.
Thus, you have to write COPY test.txt /usr/src/app/
with a trailing /
.
这篇关于如何使用Docker的COPY / ADD指令将单个文件复制到图像中的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!