参考教程：https://docs.docker.com/engine/reference/builder/

COPY has two forms:

COPY 指令有两种格式

This latter form is required for paths containing whitespace

包含空格的路径需要后一种形式

The COPY instruction copies new files or directories from and adds them to the filesystem of the container at the path .

COPY 指令从 复制新文件或目录，并将它们添加到容器的文件系统中，路径为 。

Multiple resources may be specified but the paths of files and directories will be interpreted as relative to the source of the context of the build.

可以指定多个 资源，但是文件和目录的路径将被解释为相对于构建上下文。

Each may contain wildcards and matching will be done using Go’s filepath.Match rules. For example:

每个 可能包含通配符，并且匹配将使用 Go 的 filepath.Match 规则进行。例如：

To add all files starting with “hom”:

要添加所有以 “hom” 开头的文件：

In the example below, ? is replaced with any single character, e.g., “home.txt”.

在下面的示例中，? 被替换为任何单个字符，例如 “home.txt”。

The is an absolute path, or a path relative to WORKDIR, into which the source will be copied inside the destination container.

是绝对路径，或者是相对于 WORKDIR 的路径，源将被复制到目标容器内。

The example below uses a relative path, and adds “test.txt” to /relativeDir/:

下面的示例使用相对路径，并将 “test.txt” 添加到 /relativeDir/：

Whereas this example uses an absolute path, and adds “test.txt” to /absoluteDir/

而此示例使用了绝对路径，并将 “test.txt” 添加到 /absoluteDir/ 中

When copying files or directories that contain special characters (such as [ and ]), you need to escape those paths following the Golang rules to prevent them from being treated as a matching pattern. For example, to copy a file named arr[0].txt, use the following;

在添加包含特殊字符（例如 [ 和 ]）的文件或目录时，您需要按照 Golang 规则转义那些路径，以防止将它们视为匹配模式。例如，要添加名为 arr[0].txt 的文件，请使用以下命令；

Note

If you build using STDIN (docker build - < somefile), there is no build context, so COPY can’t be used.

注意

如果您使用 STDIN 进行构建（docker build - < somefile），则没有构建上下文，因此无法使用 COPY。

Optionally COPY accepts a flag --from= that can be used to set the source location to a previous build stage (created with FROM .. AS ) that will be used instead of a build context sent by the user. In case a build stage with a specified name can’t be found an image with the same name is attempted to be used instead.

可选地，COPY 接受一个标志 --from=，该标志可用于将源位置设置为先前的构建阶段（由 FROM .. AS 创建），该标志将代替构建用户发送的上下文。如果找不到具有指定名称的构建阶段，则尝试改用具有相同名称的镜像。

COPY obeys the following rules:

COPY 遵守以下规则：

The path must be inside the context of the build; you cannot COPY ../something /something, because the first step of a docker build is to send the context directory (and subdirectories) to the docker daemon.

路径必须在构建的上下文内部；您不能执行 COPY ../something /something，因为 docker build 的第一步是将上下文目录（和子目录）发送到 docker 守护进程。

If is a directory, the entire contents of the directory are copied, including filesystem metadata.

如果 是目录，则复制目录的整个内容，包括文件系统元数据。

Note

The directory itself is not copied, just its contents.

注意

目录本身不会被复制，只是其内容被复制。

If is any other kind of file, it is copied individually along with its metadata. In this case, if ends with a trailing slash /, it will be considered a directory and the contents of will be written at /base().

如果 是任何其他类型的文件，则会将其及其元数据一起单独复制。在这种情况下，如果 以尾斜杠 / 结尾，则它将被视为目录，并且 的内容将被写在 /base() 中。

If multiple resources are specified, either directly or due to the use of a wildcard, then must be a directory, and it must end with a slash /.

如果直接或由于使用通配符而指定了多个 资源，则 必须是目录，并且必须以斜杠 / 结束。

If does not end with a trailing slash, it will be considered a regular file and the contents of will be written at .

如果 不以斜杠结尾，则将其视为常规文件，并且 的内容将被写入。

If doesn’t exist, it is created along with all missing directories in its path.

如果 不存在，则会与路径中所有缺少的目录一起创建它。

Note

The first encountered COPY instruction will invalidate the cache for all following instructions from the Dockerfile if the contents of have changed. This includes invalidating the cache for RUN instructions. See the Dockerfile Best Practices guide – Leverage build cache for more information.

注意

如果 的内容已更改，则遇到的第一个 COPY 指令将使 Dockerfile 中所有以下指令的缓存无效。这包括使 RUN 指令的高速缓存无效。有关更多信息，请参见 Dockerfile 最佳实践指南-利用构建缓存。

介绍了 Dockerfile 中 COPY 指令的使用。