docker run -v 情況說明

1、【已驗證】docker -v 掛載會以宿主機情況為准，如果容器路徑有文件將被丟失並以宿主機路徑為准；

因此可以先啟動鏡像把路徑文件拷出來到宿主機

 

參考：nginx docker主頁說明 https://hub.docker.com/_/nginx

Complex configuration

$ docker run --name my-custom-nginx-container -v /host/path/nginx.conf:/etc/nginx/nginx.conf:ro -d nginx

For information on the syntax of the nginx configuration files, see the official documentation (specifically the Beginner's Guide).

If you wish to adapt the default configuration, use something like the following to copy it from a running nginx container: // 意思是正式運行docker之前，先把容器路徑文件放到宿主機，再正式使用掛載啟動

$ docker run --name tmp-nginx-container -d nginx
$ docker cp tmp-nginx-container:/etc/nginx/nginx.conf /host/path/nginx.conf
$ docker rm -f tmp-nginx-container

2、【已驗證，但不代表全部情況（vm上跑docker）】映射文件會因為宿主機生成文件同名的路徑 而失敗，可以先在宿主機生成同名文件（vm上跑docker不行） 或者 使用“1、”的解決方案；

【已溯源】Use bind mounts

https://docs.docker.com/storage/bind-mounts/ 

Differences between -v and --mount behavior

Because the -v and --volume flags have been a part of Docker for a long time, their behavior cannot be changed. This means that there is one behavior that is different between -v and --mount.

If you use -v or --volume to bind-mount a file or directory that does not yet exist on the Docker host, -v creates the endpoint for you. It is always created as a directory.

If you use --mount to bind-mount a file or directory that does not yet exist on the Docker host, Docker does not automatically create it for you, but generates an error.