from the insert-systemd-rant-here dept.
So, in previous posts, I've talked about the fact that SoylentNews currently is powered on Ubuntu 14.04 + a single CentOS 6 box. Right now, the sysops have been somewhat deadlocked on what we should do going forward for our underlying operating system, and I am hoping to get community advice. Right now, the "obvious" choice of what to do is simply do-release-upgrade to Ubuntu 16.04. We've done in-place upgrades before without major issue, and I'm relatively certain we could upgrade without breaking the world. However, from my personal experience, 16.04 introduces systemd support into the stack and is not easily removable. Furthermore, at least in my personal experience, working with journalctl and such has caused me considerable headaches which I detailed in a comment awhile ago.
Discounting systemd itself, I've also found that Ubuntu 16.04 seems less "polished", for want of a better word. I've found I've had to do considerably more fiddling and tweaking to get it to work as a server distro than I had to do with previous releases, as well as had weird issues with LDAP. The same was also true when I worked with recent versions with Debian. As such, there's been a general feeling with the sysops that it's time to go somewhere else.
Below the fold are basically the options as we see them, and I hope if the community can provide some interesting insight or guidance.
Right now, we have about three years before security updates for 14.04 stop, and we are absolutely forced to migrate or upgrade. However, we're already hitting pain due to outdated software; I managed to briefly hose the DNS setup over the weekend trying to deploy CAA records for SN due to our version of BIND being outdated. When TLS 1.3 gets standardized, we're going to have a similar problem with our frontend load balancers. As such, I want to get a plan in place for migration so we can start upgrading over the next year instead of panicking and having to do something at the last moment
The SN Software Stack
As with any discussion for server operating system, knowing what our workloads and such is an important consideration. In short, this is what we use for SN, and the software we have to support
- nginx - Loadbalancing/SSL Termination
- Apache 2.2 + mod_perl - rehash (we run it with a separate instance of Apache and Perl, and not the system copy)
- MySQL Cluster for production
- MySQL standard for secondary services
- Kerberos + Hesiod - single-signon/authetication
- Postfix+Squirrelmail - ... mail
In addition, we use mandatory application controls (AppArmor) to limit the amount of stuff a given process can access for critical services to try and help harden security. We'd like to maintain support for this feature to whatever we migrate, either continuing with AppArmor, switching to SELinux, or using jails/zones if we switch operating systems entirely.
Right now, we've floated a few options, but we're willing to hear more.
A non-systemd Linux distro
The first choice is simply migrate over to a distribution where systemd is not present or completely optional. As of writing, Arch Linux, Gentoo, and Slackware are three such options. Our requirements for a Linux distribution is a good record of updates and security support as I don't wish to be upgrading the system once a week to a new release.
I'm aware of the Devuan project, and at first glance, it would seem like an obvious choice; Debian without systemd is the de-facto tagline. However, I've got concerns about the long-term suitability of the distribution, as well as an intentional choice to replace much of the time-tested Debian infrastructure such as the testing archive with a git-powered Jenkins instance in it's place. Another option would be slackware, but Slackware has made no indication that they won't adapt systemd, and is historically very weak with in-place upgrading and package management in general. Most of the other distributions on without-systemd.org are either LiveCDs, or are very small minority distros that I would be hesitant to bet the farm on with.
On the other side of the coin, and an option favored by at least some of the staff is to migrate to Gentoo or Arch, which are rolling-release. For those unaware, a rolling release distribution basically always has the latest version of everything. Security updates are handled simply by updating to the latest upstream package for the most part. I'm not a huge fan of this option, as we're dependent on self-built software, and it's not unheard of for "emerge world" to break things during upgrades due to feature changes and such. It would essentially require us to manually be checking release notes, and crossing our fingers every time we did a major upgrade. We could reduce some of this pain by simply migrating all our infrastructure to the form of ebuilds so that at least they would get rebuild as part of upgrading, but I'm very very hesitant about this option as a whole, especially for multiple machines.
Switch to FreeBSD/illumos/Other
Another way we could handle the problem is simply jump off the Linux ship entirely. From a personal perspective, I'm not exactly thrilled on the way Linux as a collective whole has gone for several years, and I see the situation only getting worse with time. As an additional benefit, switching off Linux gives us the possiblity of using real containers and ZFS, which would allow us to further isolate components of the stack, and give us the option to do rollbacks if ever necessary on a blocked upgrade; something that is difficult to impossible with most Linux distributions. As such, I've been favoring this option personally, though I'm not sold enough to make the jump. Two major options attract me of these two:
FreeBSD has been around a long time, and has both considerable developer support, and support for a lot of features we'd like such as ZFS, jails, and a sane upstream. FreeBSD is split into two components, the core stack which is what constitutes a release, and the ports collection which is add-on software. Both can be upgraded (somewhat) independently of each other, so we won't have as much pain with outdated server components. We'd also have the ability to easy create jails for things like rehash, MySQL, and such and easily isolate these components from each other in a way that's more iron-clad than AppArmor or SELinux.
illumos is descended from OpenSolaris, and forked after Oracle closed up the source code for Solaris 11. Development has continued on it (at a, granted, slower place). Being the originator of ZFS, it has class A support for it, as well as zones which are functionally equivalent to FreeBSD jails. illumos also has support for SMF, which is essentially advanced service management and tracking without all the baggage systemd creates and tendrils throughout the stack. Zones can also be branded to run Linux binaries to some extent so we can handle migrating the core system over by simply installing illumos, restoring a backup into a branded zone, and then piecemeal decommissioning of said zone. As such, as an upgrade choice, this is fairly attractive. If we migrate to illumos, we'll either use the SmartOS distribution, or OpenIndiana.
Right now, we're basically on the fence with all options, so hopefully the community can provide their own input, or suggest other options we're not aware of. I look forward to your comments below!
So after an extended period of inactivity, I've finally decided to jump back into working on SoylentNews and rehash (the code that powers the site). As such, I've decided to scratch some long-standing itches. The first (and easiest) to deploy was HSTS to SoylentNews. What is HSTS you may ask?
HSTS stands for HTTP Strict Transport Security and is a special HTTP header that signifies that a site should only be connected to over HTTPS and causes the browser to automatically load encrypted versions of a website should it see a regular URL. We've forbid non-SSL connections to SN for over a year, but without HSTS in place, a man-in-the-middle downgrade attack was possible by intercepting the initial insecure page load.
One of the big views I have towards SoylentNews is we should be representative of "best practices" on the internet. To that end, we deployed IPv6 publicly last year, and went HTTPS-by-default not long after that. Deploying HSTS continues this trend, and I'm working towards implementing other good ideas that rarely seem to see the light of day.
Check past the break for more technical details.
Two months ago, I polled the community for advice on the underlying operating system that should power SoylentNews (SN). After reading comments, and some recent experiences in my personal and professional life, we are migrating to Gentoo as the operating system of choice. As of right now, we've already migrated our development box, lithium, over, and using it as a shakedown to see how painful the overall migration will be. I'm pleased to report that, aside from varnish (an HTTP accelerator), the process went relatively smoothly.