Talk for Docker Singapore Meetup #2 at SingTel

class: center, middle

# Why CoreOS sucks

The presentation form of the blog <http://dabase.com/blog/Experiencing_CoreOS+Docker/>

[SG Docker Singapore Meetup #2](http://www.meetup.com/Docker-Singapore/events/217758232/)

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# Who is Kai Hendry ? [@kaihendry](http://twitter.com/kaihendry)

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# What is CoreOS?

## [8 million USD](http://www.crunchbase.com/organization/coreos) meets Linux & [SystemD](http://en.wikipedia.org/wiki/Systemd)

oh... and <img src=http://s.natalian.org/2014-11-14/docker-logo.png>

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# Why does Docker need CoreOS?

Because Linux distros suck even more. **WAY TOO MUCH BLOAT**.

* Too general
* Too annoying to keep upto date

You really just need an uptodate Linux stable kernel + stable systemd + stable Docker...

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# So why do I hate CoreOS

## 1. [Btrfs](http://en.wikipedia.org/wiki/Btrfs) is about 10x more complex than Ext4

What does it give you?

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# 2. Poor design when it comes to user / permissions

## Readonly filesystems ✔
## sudo ✖
## users ✖

`setfacl` madness ensues

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# 3. Poor design when it comes to logging / monitoring

[Journalctl](https://bugs.freedesktop.org/show_bug.cgi?id=78172) logging is a cluster f☠!k

How do you log from your container to journalctl?

Tooling assumptions that you are going to run cluster

All or 1 = nothing

No monitoring convenience

Heady mix of systemd services ... and [etcd / cloudconfig / fleetctl](https://www.digitalocean.com/community/tutorials/how-to-set-up-a-coreos-cluster-on-digitalocean)

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# 4. No cron

## [systemd timers](https://wiki.archlinux.org/index.php/Systemd/Timers)

@hourly curl http://example.com/webhook

becomes

x220:~$ systemctl list-timers | grep foo
	Wed 2014-11-19 14:00:00 SGT  32min left n/a                          n/a       foo.timer                    foo.service
	x220:~$ cat /etc/systemd/system/foo.{timer,service}
	[Unit]
	Description=Run foo hourly

[Timer]
	OnCalendar=hourly

[Install]
	WantedBy=timers.target
	[Unit]
	Description=Foo example

[Service]
	ExecStart=/usr/bin/curl http://example.com/webhook

[Pros and Cons](https://wiki.archlinux.org/index.php/Systemd/Timers#As_a_cron_replacement)

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background-image: url(http://s.natalian.org/2014-11-19/1416365044_1364x748.png)

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# 5. Update engine / version should be just gitfs ffs

* Uses ChromeOS's complex architecture
* Random reboots `fleetctl`
* Can you roll back? No?
* Stable Docker please

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# 6. CoreOS packaging is just WEIRD

## WTH DOES [/etc/ssh/sshd_config](http://s.natalian.org/2014-11-19/sshd_config) COME FROM?

Not here:

* https://github.com/coreos/coreos-overlay
* https://github.com/coreos/portage-stable/tree/master/net-misc/openssh

UPDATE: <https://github.com/coreos/init/blob/master/configs/sshd_config>

# Want to bring your tools?

No tmux and they expect your container to map back to the rootfs. Bit crazy.

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# A sea change

1. [Btrfs](http://en.wikipedia.org/wiki/Btrfs) is about 10x more complex than Ext4
2. Poor design when it comes to user / permissions
3. Poor design when it comes to logging / monitoring
4. <strike>No cron</strike>
5. Update engine / version should be just gitfs ffs
6. CoreOS packaging is just WEIRD

Things to look forward to <http://kubernetes.io/>

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# Is you want to stay sane

And use [`chroot`](http://unix.stackexchange.com/questions/127001/linux-lxc-vs-freebsd-jail/141595#141595) ;)

<blockquote class="twitter-tweet" lang="en"><p><a href="https://twitter.com/hashtag/docker?src=hash">#docker</a> has now had more security issues within a year then <a href="https://twitter.com/hashtag/freebsd?src=hash">#freebsd</a> <a href="https://twitter.com/hashtag/jails?src=hash">#jails</a> has had since 2000. Good job <a href="https://twitter.com/hashtag/techbros?src=hash">#techbros</a>. <a href="http://t.co/Qx6OMjmqlI">http://t.co/Qx6OMjmqlI</a></p>— BP (@creepingfur) <a href="https://twitter.com/creepingfur/status/543685725825146880">December 13, 2014</a></blockquote>
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