How to copy files from host to Docker container?

Question

I am trying to build a backup and restore solution for the Docker containers that we work with.

I have Docker base image that I have created, ubuntu:base, and do not want have to rebuild it each time with a Docker file to add files to it.

I want to create a script that runs from the host machine and creates a new container using the ubuntu:base Docker image and then copies files into that container.

How can I copy files from the host to the container?

Answer 1

The cp command can be used to copy files.

One specific file can be copied TO the container like:

docker cp foo.txt container_id:/foo.txt

One specific file can be copied FROM the container like:

docker cp container_id:/foo.txt foo.txt

For emphasis, container_id is a container ID, not an image ID. (Use docker ps to view listing which includes container_ids.)

Multiple files contained by the folder src can be copied into the target folder using:

docker cp src/. container_id:/target
docker cp container_id:/src/. target

Reference: Docker CLI docs for cp

In Docker versions prior to 1.8 it was only possible to copy files from a container to the host. Not from the host to a container.