Try out docker image shrinking with ReproZip

[remram44]

There is some interest in shrinking Docker images, which usually contain more stuff that is needed for the one task they are to perform, since they are created from a full operating system image. For example here: blog post (tool).

ReproZip could totally do that, it just needs some wrapper code to interact with the Docker image (inject itself into it, get pack out?)

[satra]

@remram44 - i'm trying to run reprozip inside a docker container, connected to it in interactive mode. but even doing something like this reprozip trace cat README.md appears to take for ever.

i have reprozip installed using the vida-nyu conda channel inside a docker container.

[remram44]

Yes, I ran into this recently! The problem is that Docker has seccomp rules preventing the use of ptrace inside the container (among other "unusual" system calls).

Because of a tragic oversight, ReproZip doesn't print a message when that happens (fixed by 8d131ed6 which will be in 1.0.7), but the program doesn't execute.

Using the Docker option --security-opt seccomp:unconfined should fix this (or if security is an issue, write your own seccomp profile, making sure to enable ptrace).

See also the Docker documentation on seccomp.

[satra]

great - that worked.

[chrisgorgo]

I just run into this. It would be great if reprozip would give a meaningful (or googlable) error instead of just hanging.

[remram44]

I released reprozip 1.0.7 which correctly display the message, and links to this new troubleshooting entry.

[remram44]

@kaczmarj seems to be doing just this in https://github.com/kaczmarj/neurodocker

[satra]

@remram44 - yes, he is working with us :)