docker - Copy files from container to local using shell script

Question

I m trying to write a shell script that builds/runs containers and then copies files from docker container to host.

docker build . -t container:latest
docker run -t -d container /bin/bash
docker cp container_id:/xyz/xyz.txt /tmp

How can I capture the container id from the build and then use it within the shell script? Thanks for your help.

Answer 1

The first option would be to simply store the container ID in a variable.

docker build . -t container:latest
container_id="$(docker run -t -d container /bin/bash)"
docker cp "$container_id":/xyz/xyz.txt /tmp

Docker also allows you to specify a container name.

docker build . -t container:latest
docker run -t --name NAME -d container /bin/bash
docker cp NAME:/xyz/xyz.txt /tmp