下面是关于如何在docker中使用CP命令的解释，您的问题与 /。在$ code> SRC_PATH

  SRC_PATH不以/结尾。 
将源目录复制到此目录中

 SRC_PAPTH以/结尾。 
将源目录的内容复制到此目录中
 

Am I missing something when I try to copy files from one folder to a existing container folder:

Doc

I want to copy files within the build(host) folder to html in my container:

docker cp ./src/build b081dbbb679b:/usr/share/nginx/html

To be clear; I need to copy from host to container.

But it copies the whole build folder and copies it to ..html/build

I just need the files(and sub folders) within the build folder to be copied into ..html.

Am I missing something or do I have to copy each file one by one?

Here is the explanation on how to use the CP command in docker, which will fix your issue with /. in end of SRC_PATH

SRC_PATH does not end with /.
the source directory is copied into this directory

SRC_PAPTH does end with /.
the content of the source directory is copied into this directory