how to rsync from a host computer to docker container using docker cp

Question

I am trying to run following:

1. start a container in background

docker run -dit -p 8090:80 --name container repository:dockerfile bash

2. I want to exclude sub directory /data from /test

docker cp /Users/$USER/test container:/test

3. I thought of using rsync for this docker exec rsync -avP --exclude /Users/$USER/test/data /Users/$USER/test/ container:/test/

I get below error:

rsync: Failed to exec ssh: No such file or directory (2)
rsync error: error in IPC code (code 14) at pipe.c(85) [sender=3.1.0]
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(226)
[sender=3.1.0]

How do I rsync from host to container?

Answer 1

Map the host directory first, into the container:

docker run -v /Users/$USER/test:/temp-test -dit -p 8090:80 --name container repository:dockerfile bash

Then use the rsync as follows:

docker exec container rsync -avP --exclude /temp-test/data /temp-test/ /test/

Answer 2

The way to use rsync to copy files into a Docker container

Make sure your Docker container has rsync installed, and define this alias:

alias drsync="rsync -e 'docker exec -i'"

Now, you can use rsync with containers as if they are remote machines:

drsync -av /source/ container:/destination/

Answer 3

When you run docker exec rsync [...] you execute the rsync command in your container. The path /Users/$USER/test/ corresponds to a directory on you host system, so rsync has a hard time finding it in your container.

There are basically two ways to use rsync to transfer files into a container:

1. You can install an ssh server on you host system and use rsync to connect from within your container to the host system from the outside. If you have a running ssh server on you host and the host is reachable under the name host you can do

   docker exec rsync -avP --exclude /Users/$USER/test/data host:/Users/$USER/test /test
   

2. You can install an ssh server inside the container and use rsync on your host system to connect to the container from the outside. I assume your container is reachable under the name container, then you can do

   rsync avP --exclude /Users/$USER/test/data /Users/$USER/test container:/test
   

   In this case you have to make sure that the ssh port (default is 22) is published by the docker daemon.

Answer 4

This should mirror the command you attempted in the OP...

rsync -avPe 'docker exec -i' --exclude /Users/$USER/test/data /Users/$USER/test/ container:/test/

It works similarly to get files out of the container.

Credit to https://github.com/moby/moby/issues/13660#issuecomment-165500701

Answer 5

The

rsync: Failed to exec ssh: No such file or directory (2)

is caused because ssh is not installed for you container. You install it manual or add it to your requirements file to install it automaticly.