`docker cp` 不会将文件复制到容器中

Question

我有一个 dockerized 项目。我构建，将文件从主机系统复制到 docker 容器中，然后 shell 到容器中，发现该文件不存在。docker cp应该如何工作？

$ docker build -q -t foo .
Sending build context to Docker daemon    64 kB
Step 0 : FROM ubuntu:14.04
 ---> 2d24f826cb16
Step 1 : MAINTAINER Brandon Istenes <redacted@email.com>
 ---> Using cache
 ---> f53a163ef8ce
Step 2 : RUN apt-get update
 ---> Using cache
 ---> 32b06b4131d4
Successfully built 32b06b4131d4
$ docker cp ~/.ssh/known_hosts foo:/root/.ssh/known_hosts
$ docker run -it foo bash
WARNING: Your kernel does not support memory swappiness capabilities, memory swappiness discarded.
root@421fc2866b14:/# ls /root/.ssh
root@421fc2866b14:/#

Answer 1

因此，图像和容器的名称有些混淆。显然，cp 操作作用于与我用 run 命令提出的容器不同的容器上。无论如何，正确的程序是：

# Build the image, call it foo-build
docker build -q -t foo-build .

# Create a container from the image called foo-tmp
docker create --name foo-tmp foo-build

# Run the copy command on the container
docker cp /src/path foo-tmp:/dest/path

# Commit the container as a new image
docker commit foo-tmp foo

# The new image will have the files
docker run foo ls /dest