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Inside these pages you will find a collection of my personal ramblings (including security disclosures, my thoughts on various topics, and anything else that I feel like writing about). All of the opinions stated here are solely my own, and are released under the Creative Commons BY-SA 4.0 license.

Tag: Suse

umoci: a New Tool for OCI Images Aleksa Sarai, 29 November 2016.

Very recently, I've been working on implementing the required tooling for creating and modifying Open Container Initiative images without needing any external components. The tool I've written is called umoci and is probably one of the more exciting things I've worked on in the past couple of months. In particular, the applications of umoci when it comes to SUSE tooling like the Open Build Service or KIWI is what really makes it exciting.

containers free software kiwi oci suse


Adventures into ptrace(2) Hell Aleksa Sarai, 03 July 2016.

As part of my work on rootless containers, I found that many tools try to drop privileges. This makes those tools break inside rootless containers, so I spent a week or two working on a tool that allows users to shim out all of the "drop privileges" syscalls. Here is documented the pain that I went through while figuring out how ptrace(2) is meant to work.

containers free software rant runc suse


Rootless Containers with runC Aleksa Sarai, 27 June 2016.

There has been a lot of work within the runC community recently to get proper "rootless containers". I've been working on this for a couple of months now, and it looks like it's ready. This will be the topic of my talk at ContainerCon Japan 2016.

containers free software runc suse


Debugging why ping was Broken in Docker Images Aleksa Sarai, 04 March 2016.

All complicated bugs start with the simplest of observations. I recently was assigned a bug on our openSUSE Docker images complaining that ping didn't work. After a couple of days of debugging, I was taken into a deep and dark world where ancient Unix concepts, esoteric filesystem features and new kernel privilege models culminate to produce this bug. Strap yourself in, this is going to be a fun ride.

bugs docker free software kernel kiwi suse


Dockerinit and Dead Code Aleksa Sarai, 21 January 2016.

After running into insane amounts of very weird issues with gccgo with Docker, some of which were actual compiler bugs, someone on my team at SUSE asked the very pertinent question "just exactly what is dockerinit, and why are we packaging it?". I've since written a patch to remove it, but I thought I'd take the time to talk about dockerinit and more generally dead code (or more importantly, code that won't die).

docker free software programming suse


Docker Internals and Implementing Rebase Aleksa Sarai, 12 December 2015.

SUSE's semi-annual Hackweek was last week and I decided to work on implementing docker rebase, mainly to learn about the internal image format of Docker and see whether it was possible to improve how the updating of Docker images works in practice (either rebuilding or zypper-docker).

docker free software hackweek suse