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

Answer 1

docker cp SRC_PATH CONTAINER_ID:DEST_PATH

For example, I want to copy my file xxxx/download/jenkins to tomcat

I start to get the id of the container Tomcat

docker ps

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                    NAMES
63686740b488        tomcat              "catalina.sh run"   12 seconds ago      Up 11 seconds       0.0.0.0:8080->8080/tcp   peaceful_babbage

docker cp xxxx/download/jenkins.war  63686740b488:usr/local/tomcat/webapps/

Answer 2

Assuming the container is already running, type the given command:

# cat /path/to/host/file/ | docker exec -i -t <container_id> bash -c "/bin/cat > /path/to/container/file"

To share files using shared directory, run the container by typing the given command:

# docker run -v /path/to/host/dir:/path/to/container/dir ...

Note: Problems with permissions might arise as container's users are not the same as the host's users.

Answer 3

1. Get container name or short container id:

   $ docker ps
   

2. Get full container id:

   $ docker inspect -f   '{{.Id}}'  SHORT_CONTAINER_ID-or-CONTAINER_NAME
   

3. Copy file:

   $ sudo cp path-file-host /var/lib/docker/aufs/mnt/FULL_CONTAINER_ID/PATH-NEW-FILE
   

EXAMPLE:

$ docker ps

CONTAINER ID      IMAGE    COMMAND       CREATED      STATUS       PORTS        NAMES

d8e703d7e303   solidleon/ssh:latest      /usr/sbin/sshd -D                      cranky_pare

$ docker inspect -f   '{{.Id}}' cranky_pare

or

$ docker inspect -f   '{{.Id}}' d8e703d7e303

d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5

$ sudo cp file.txt /var/lib/docker/aufs/mnt/**d8e703d7e3039a6df6d01bd7fb58d1882e592a85059eb16c4b83cf91847f88e5**/root/file.txt

Answer 4

The cp command can be used to copy files.

One specific file can be copied TO the container like:

docker cp foo.txt mycontainer:/foo.txt

One specific file can be copied FROM the container like:

docker cp mycontainer:/foo.txt foo.txt

For emphasis, mycontainer is a container ID, not an image ID.

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

docker cp src/. mycontainer:/target
docker cp mycontainer:/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.

Answer 5

Typically there are three types:

1. From a container to the host

   docker cp container_id:./bar/foo.txt .
   

2. From the host to a container

   docker exec -i container_id sh -c 'cat > ./bar/foo.txt' < ./foo.txt
   

3. From a container to a container mixes 1 and 2

   docker cp container_id1:./bar/foo.txt .
   
   docker exec -i container_id2 sh -c 'cat > ./bar/foo.txt' < ./foo.txt
   

Answer 6

The cleanest way is to mount a host directory on the container when starting the container:

{host} docker run -v /path/to/hostdir:/mnt --name my_container my_image
{host} docker exec -it my_container bash
{container} cp /mnt/sourcefile /path/to/destfile