How to properly create a tar archive to import with docker-CodePudding

I need to extract the filesystem of a debian image onto the host, modify it, then repackage it back into a docker image. I'm using the following commands:

docker export container_name > archive.tar
tar -xf archive.tar -C debian/

modifying the file system here

tar -cpjf archive-modified.tar debian/
docker import archive-modified.tar debian-modified
docker run -it debian-modified /bin/bash

After I try to run the new docker image I get the following error:

docker: Error response from daemon: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: exec: "/bin/bash": stat /bin/bash: no such file or directory: unknown.
ERRO[0000] error waiting for container: context canceled

I've tried the above steps without modifying the file system at all and I get the same behavior. I've also tried importing the output of docker export directly, and this works fine. This probably means I'm creating the new tar archive incorrectly. Can anyone tell me what I'm doing wrong?

CodePudding user response：

Take a look at the archive generated by docker export:

# tar tf archive.tar | sort | head
bin/
bin/bash
bin/cat
bin/chgrp
bin/chmod
bin/chown
bin/cp
bin/dash
bin/date
bin/dd

And then at the archive you generate with your tar -cpjf ... command:

# tar tf archive-modified.tar | sort | head
debian/
debian/bin/
debian/bin/bash
debian/bin/cat
debian/bin/chgrp
debian/bin/chmod
debian/bin/chown
debian/bin/cp
debian/bin/dash
debian/bin/date

You've moved everything into a debian/ top-level directory, so there is no /bin/bash in the image (it would be /debian/bin/bash, and probably wouldn't work anyway because your shared libraries aren't in the expected location, either.

You probably want to create the updated archive like this:

# tar -cpjf archive-modified.tar -C debian/ .