post: new article about supporting new users

And more, around the maintenance and WIP stuff.

Signed-off-by: Matthieu Baerts (NGI0) <[email protected]>

Author: matttbe

_posts/2024-05-03-supporting-new-users.md

@@ -0,0 +1,96 @@
+---
+layout: post
+title:  "Supporting new users"
+---
+
+During the last few months, a lot of work has been done to help other kernel
+developers, and stabilize the current solution. It was really time to focus on
+supporting new users and application developers. Read on to find out more about
+what happened in April!
+
+<!--more-->
+
+## MPTCP case
+
+Like many consequent projects modifying the Linux kernel, the development of the
+MPTCP Linux Upstream project has been mainly supported by companies, for their
+specific use-cases.
+
+Because using multiple paths at the same time is still not common these days,
+most OS's need to be configured to let MPTCP use different paths, and the apps
+need to ask to use MPTCP. Companies working on the Linux implementation already
+know about MPTCP, and how to configure it. Their clients have also certainly
+been told what it is and how to use it in their product. But it has never been a
+priority to have good documentation for the community. Of course, we were, and
+still are, open to answer questions about MPTCP, but not everybody is curious
+enough to find out what MPTCP is, how to configure it, and/or to ask questions
+if something is not clear. That's a shame because attracting new users,
+generally also means new contributors (bug reports, fixes, features, etc.), and
+a better solution at the end.
+
+This situation is now changing thanks to the [NLnet
+project](https://nlnet.nl/project/MPTCP-deployability) I'm participating to,
+funded through [NGI0 Core](https://nlnet.nl/core).
+
+## New website
+
+[mptcp.dev](https://www.mptcp.dev) has been completely rewritten and published
+in April.
+
+Before, the documentation about MPTCP in the Linux kernel was available in
+different places:
+- [mptcp.dev](https://www.mptcp.dev) was a summary of the wiki page, and assumed
+  people already knew about MPTCP -- see the previous version
+  [here](https://github.com/multipath-tcp/mptcp.dev/blob/531801e/README.md).
+- The [wiki](https://github.com/multipath-tcp/mptcp_net-next/wiki) had some
+  info, but it was also redirecting to info from different sources, including
+  talks and articles, and out of date info -- see the previous version
+  [here](https://github.com/multipath-tcp/mptcp_net-next/wiki/Home/34ba2883e2a30b15a149df94a941b446eb51e1d6).
+- The documentation attached to the kernel only contained info about the
+  [MPTCP sysfs variables](https://docs.kernel.org/networking/mptcp-sysctl.html),
+  and recently about the
+  [`mptcp_pm` Netlink API](https://docs.kernel.org/networking/netlink_spec/mptcp_pm.html).
+- A [website](https://mptcp-apps.github.io/mptcp-doc/mptcp.html) has been
+  initiated by the community, but never finished.
+- RedHat has [documentation](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/configuring_and_managing_networking/index#getting-started-with-multipath-tcp_configuring-and-managing-networking),
+  but centred around RHEL.
+
+When helping Maxime Durov, Dorian Craps, and Olivier Bonaventure to add native
+MPTCP support to apps like
+[lighttpd](https://github.com/lighttpd/lighttpd1.4/pull/132) and
+[curl](https://github.com/curl/curl/pull/13278) as part of a project linked to
+the UCLouvain, we realized it was urgent to have a website dedicated to new
+users and apps developers, regrouping all required info about MPTCP, what it is,
+how to configure it, use it, and more. With their great help, the website has
+been updated, and announced on [social media](https://social.kernel.org/mptcp).
+It even appeared at the top of [Hacker News](https://news.ycombinator.com/),
+bringing thousands of visitors! So far, we got positive feedback: the new
+website seems to be answering questions from new users, and app developers, and
+even brought new contributors!
+
+## What's next?
+
+Various works have been started recently: adding missing features that are
+important for some apps and libs which want to support MPTCP natively, a new lib
+for MPTCP in Rust, a test service, adapting the packet scheduler API to support
+new use-cases, and improving some corner cases, etc. That's quite a bit of work
+in parallel, but that's coming "soon"!
+
+But before, it is also time to wrap up all new but mature enough features to
+send upstream for the inclusion in the future v6.10 version. It looks like we
+have up to the 2nd week of May to have them accepted in the 'net-next' tree.
+Check a [previous post]({% post_url 2024-03-04-backports %}) to know more about
+the kernel development cycle.
+
+## Team work
+
+As always, it is important to note that what I presented here so far is mostly
+what I was working on. But I'm not alone in this project. For example, Geliang
+finished supporting the 'last time' fields in `MPTCP_INFO`, and did some
+refactoring in the BPF selftests to reduce duplicated code ; Paolo fixed issues
+reported by Christoph thanks to SyzKaller ; Mat helped with the code and website
+reviews ; Gregory (new contributor!) is doing some experimentation with the
+packet scheduler API, and fixing bugs along the way ; Dorian and Maxime
+continued to add native MPTCP support in userspace apps.
+
+A great community!