
CoreOS Stable Release - brynary
https://coreos.com/blog/stable-release/
======
rckclmbr
We recently switched (like 2 weeks ago) our project from deployment on ubuntu
servers via 'git pull' managed with supervisord to docker/coreos/fleet, and
it's been epic. While coreos is built for large clusters, we run a 3 host
cluster in ec2, and couldn't be happier. We switched from multiple servers
running 1 instance of each service to load balancing all instances on these 3
hosts. This increased uptime, made deployment and management easier, and gave
us the benefits of docker as well (verifying things work locally).

There's only 2 real problems, both of them very minor:

* fleet managing state. We've had to manually kill containers sometimes, and destroy systemd services before we could start it again.

* all EC2 amis use ebs backed instances. We haven't used a higher-IOPs ebs backed instance because the only delay we see are in startup times (which doesn't matter, just longer rolling deploys). But an instance-backed ami would be nice.

~~~
superuser2
How do you handle persistent storage in a fault-tolerant way?

You could technically pin your MySQL container to one host, but that seems to
defeat the point of fleet. I considered trying to mount an iSCSI target to run
the database from, but CoreOS doesn't have a working iSCSI initiator.

I guess I could just run all the persistent stuff on a more traditional OS,
but then why mess with CoreOS at all?

~~~
rckclmbr
We use Amazon RDS and S3. Only applications are run in the cluster.

~~~
superuser2
Yeah, this seems to be common.

CoreOS seems to do a decent job as the application layer for something
operating in a larger cloud that provides database and file storage as
services, like Amazon or OpenStack. However, I think Docker has the potential
to eliminate the need for infrastructure-level "clouds" to be so complex. The
basic unit can be the container instead of the instance, so you don't need
fancy automated instance management and all that. It'd be nice if you could
also obviate the need for the other external services, and just run everything
in containers on metal.

I was really excited by CoreOS as a way to do this, but it seems to fighting
me at every turn. It seems much easer to just wire together the REST APIs of
several Ubuntu/CentOS nodes running Docker.

~~~
opendais
I haven't used CoreOS, mainly just watched, but have you tried deploying a
Galera cluster at a scale of 5 containers?

That is more likely what they'd have in mind than a single MySQL master
container.

~~~
otterley
Who uses Galera successfully? Every DBA I've ever spoken to about it has
advised me to avoid it because it's incredibly deadlock-prone.

~~~
opendais
[http://blog.scoutapp.com/articles/2013/09/24/from-mysql-
mmm-...](http://blog.scoutapp.com/articles/2013/09/24/from-mysql-mmm-to-
mariadb-galera-cluster-a-high-availability-makeover)

That explains how they chose to minimize deadlocks.

Yes, if you use it incorrectly and/or for the wrong problem space, you will
have issues. It isn't a magical solution to all problems. It is, however, an
effective solution for a specific problem space.

------
netcraft
It looks like Digital Ocean hopes to eventually support coreOS:
[http://digitalocean.uservoice.com/forums/136585-digital-
ocea...](http://digitalocean.uservoice.com/forums/136585-digital-
ocean/suggestions/4250154-suport-coreos-as-a-deployment-platform)

I can only find a tweet that linode is "considering" it:
[https://twitter.com/linode/status/488045339023532032](https://twitter.com/linode/status/488045339023532032)

anyone have any other information re vps vendor support?

~~~
thejosh
DO promises A LOT of features they do not deliver.

~~~
kelseyhightower
I personally think they will pull this one off, mainly because CoreOS will be
providing support to the DO team and help however possible to make sure DO is
added to the list of supported cloud vendors.

~~~
thejosh
Ah yes, because FreeBSD hasn't offered their help already.

------
JohnTHaller
I'm a bit confused on the licensing here. CoreOS says it's Apache 2.0
licensed. But it also says its Linux. If it includes the Linux kernel, as it
appears to, then those bits is licensed under the GPL and can not be re-
licensed as Apache 2.0. So, it's a bit disingenuous to claim the whole package
is Apache 2.0, since it isn't.

~~~
sciurus
Where is the text you find confusing? What I found about licensing says "Code
produced by the CoreOS team is licensed under the Apache 2.0 license." That's
extremely clear about what the license applies to.

[http://coreos.com/products/](http://coreos.com/products/)

~~~
rando289
Yes, for people who understand licensing stuff. For the many people who don't,
they could say that 3rd party components of CoreOS are under various open
source licenses, but the code they produce is Apache 2.0.

------
brynary
I'm very excited about this release. CoreOS, Docker and etcd are a great fit
for one another. I love the separation of concerns that is provided.

IMHO, the weakest part of CoreOS is fleet
([https://github.com/coreos/fleet](https://github.com/coreos/fleet)). Compared
to the other components in the stack, it just feels very inelegant. The
systemd configuration syntax is complex and ugly. I wonder if there will be
work invested to upgrade fleet to something that is as elegant as e.g.
etcd/Docker/CoreOS itself.

~~~
bcwaldon
fleet definitely does not provide a nice integration with docker, and we're
definitely trying to decide how we can provide a better integration story. And
yes, systemd is complex, but with that complexity comes great power.

~~~
brynary
Glad to hear you're thinking about this. Understanding the complexity provides
power, but the tradeoff in this instance doesn't feel quite right.

For example, etcd is a powerful primitive, and then more complex/sophisticated
systems can be built on top of it.

I wonder if an 80/20 solution that is simpler than fleet/systemd for pushing
work into a CoreOS cluster would be a win, and then more complex systems (e.g.
Kubernetes-esque orchestraction) could live on top of that.

~~~
vidarh
I took one look at Kubernetes, and decided that for our purposes writing our
own orchestration scripts from scratch would be simpler... So many of these
systems are hopelessly overcomplicated.

------
otterley
I'm puzzled as to why it's called "stable," while at the same time it appears
to require btrfs-on-root to be useful (i.e. for hosting Docker containers) but
that part is "experimental."

Can someone from CoreOS clarify?

~~~
philips
Where is it marked experimental on the website? Almost certainly a mistake.

~~~
robszumski
He's talking about the PXE kernel option specifically:
[http://coreos.com/docs/running-coreos/bare-metal/booting-
wit...](http://coreos.com/docs/running-coreos/bare-metal/booting-with-
pxe/#setting-up-pxelinux.cfg)

------
outside1234
Super great to see CoreOS making it to its first stable release. It really
feels like the future.

I've been reading about using vulcand to do frontend deploys and traffic
management ([http://coreos.com/blog/zero-downtime-frontend-deploys-
vulcan...](http://coreos.com/blog/zero-downtime-frontend-deploys-vulcand/))
and using ambassadors to do dynamic routing to backend stores
([http://coreos.com/blog/docker-dynamic-ambassador-powered-
by-...](http://coreos.com/blog/docker-dynamic-ambassador-powered-by-etcd/))

But it is hard to get my head around this - has anyone actually tied all of
these concepts together in a deployment that they've written up?

------
jvandyke
Flynn 1.0 release in 3, 2, 1... _crosses fingers_

~~~
danielsiders
Beta's coming soon and we're still on target to ship a production-grade stable
version of the major features in a few months.

~~~
jhuckestein
This is excellent news. Two weeks ago I looked into flynn and the various
repos had very little activity compared to deis so I went with that for now.

Edit: I posted this just FYI. I thought it'd be useful to know. Perhaps this
is a consequence of splitting the project across a large number of repos,
where some of them don't get many commits.

------
devNoise
I've been using Vagrant/Virtual to run Ubuntu LTS for my Javascript dev env.
Does it make sense switch to CoreOS? I generally run it as a headless server.
No X-windows or GUI needed.

~~~
therealmarv
Stay for now on Ubuntu. Personally I would be sceptical for some time before
the hype of a new Linux settles down. Ubuntu is proven for many many years and
stands on the shoulders of giants named Debian. CoreOS is a pretty new shiny
product which still needs to prove itself.

~~~
devNoise
Thanks. I'll keep an eye on it, but will hold off on making a switch.

------
jimmcslim
I know Hyper-V isn't particularly sexy around these parts but it appears to
work there as well. It doesn't support the Hyper-V integration services but
that's par for the course for most Linux distributions.

~~~
lucasjans
Hyper-V support interests, me, as I have a cluster of Windows hosts and would
love to add CoreOS to the mix and deploy to my private cloud when needed.

CoreOS is putting some effort into Hyper-V support. There's a way to get it
working, though I haven't tried.

Hopefully there's an elegant solution soon.

[https://groups.google.com/forum/#!topic/coreos-
dev/S3lbY2BV4...](https://groups.google.com/forum/#!topic/coreos-
dev/S3lbY2BV4bo)

