Copy file from container after the container is done

Question

I have a container that generates an mp4 file for me, which I want to download / copy to my host system after the container script has been completed.

What I managed to do is add a sleep 2m to the end of my entrypoint.sh before calling exit 0 (it's a bit hacky, I know 😅) which gives me 2 minutes to run the following command to download the mp4 file.

docker cp gource_container:/output/generated.mp4 ./

This works fine when i do it by hand, but my goal is to run it automatically via bash script.

Is there any way to cp the file to my host system after the container exits?

When I run the cp command after the container is done without sleep i get the following error:

$ docker cp gource_container:/output/generated.mp4 ./
Error: No such container:path: gource_container:/output/generated.mp4

Well. Why you don't mount your container volume to the host machine instead copy it? The file still exists in the host machine after the container is exit. — Truong Dang
– Truong Dang, Commented Aug 26, 2020 at 15:22

Paolo · Accepted Answer · 2020-08-26 15:32:15Z

4

A possible solution would be to mount your local working directory when creating a container from the image, and then copy the file over:

Example Dockerfile:

FROM ubuntu
RUN echo 'foo' > /foo.txt

Example commands:

# Build a Docker image and tag it test
$ docker build -t test .

# Launch a Docker container from the test image,mount the working directory to the /data directory on the container then copy the file of interest
$ docker run --rm -it -v $(pwd):/data test cp /foo.txt /data

# Inspect file locally
$ cat ./foo.txt
foo

edited Aug 26, 2020 at 15:32

answered Aug 26, 2020 at 15:25

Paolo

26.6k8 gold badges51 silver badges88 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Norbert Bartko Over a year ago

What does this line do? -v $(pwd):/data

Paolo Over a year ago

It mounts your working directory (pwd) to a volume named data in the container

Collectives™ on Stack Overflow

Copy file from container after the container is done

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related