# Docker usage

## if you want to install system package to docker
* 如果需要安裝新的package e.g. vim，一定要在exit docker前先commit上去!!!!
* ref : https://dywang.csie.cyut.edu.tw/dywang/docker-podman/node84.html
* docker commit -m "{commit santances}" {you container id} {name of image}:{tag name}
* 如果再執行run之前有使用 --rm
* 不要執行exit!!
* 會出現 Error response from daemon: No such container: 7ca3762acd9c 這個error
* docker images {name of image}
* 可以看到新增的images
* docker run ...
* 進入新的docker

## if you want to use virtul machine inside docker
* https://stackoverflow.com/questions/48422001/how-to-launch-qemu-kvm-from-inside-a-docker-container