Created attachment 1022155 [details] dockerfile reproducer Description of problem: After upgrading docker I can no longer cp from inside a container. I upgraded to docker-io-1.6.0-4.git350a636.fc21.x86_64 and tried docker-io-1.6.0-4.git350a636.fc21.x86_64 as well. Both fail. This is a regression in F21. That worked fine with 1.3.2 How reproducible: Outside the container use: docker cp my_container:/tmp/file-created-in-the-container ./tmp/ FATA[0000] Error response from daemon: Could not find the file ... Using ssh I can verify that the files exist Steps to Reproduce: 0. Copy the attached dockerfile into docker-dir 1. sudo docker build -t test-image docker-dir 2. sudo docker run -P --privileged=true --name xxx-name test-image 3. sudo docker cp xxx-name:/tmp/xxx /tmp/ Actual results: With 1.3.2: nothing. The file is copied. With 1.6.0: FATA[0000] Error response from daemon: Could not find the file /tmp/xxx in container xxx-name Expected results: The file should have been copied.
This is quite important to me as I base my test suite on F21 and docker, and updating docker completely breaks my test suite.
Should be fixed in docker-1.6.2. We had made a change to mount the /tmp directory by default as a tmpfs, which we are changing back to the default, which should allow this behavior to work again. We are working on a new command atomic mount which will expose the entire image to the host, and would allow you do do much more with host commands like cp, rsync ...