Intro to CoreOS...

1. Víctor S. Recio
CEO NerCore Inc,
@vsrecio / vrecio@nercore.com

2. Who am I?
Víctor S. Recio
CEO NerCore Inc,
@vsrecio
vrecio@nercore.com
Lead
● Docker Santo Domingo
● Linux Dominicana
● Golang Dominicana

3. Agenda
CoreOS
What is CoreOS?
CoreOS Overview
Install CoreOS
Etcd
What is Etcd?
Etcd Overview
Fleet
What is Fleet?
Fleet Overview
Demos

4. CoreOS
Linux Distro
Kernel
Systemd
ssh
Docker
Python
Ruby
Java
MySQL
App

5. CoreOS
Linux Distro
Kernel
Systemd
ssh
Docker
Python 2.7
Ruby
Java
MySQL 5.4
CoreOS Docker
Container
App

6. CoreOS
CoreOS
Linux
Distro
rkt
Docker
systemd etcd fleet
Container
system
init
system
Distributed
key-value
store
Cluster
Manager

7. CoreOS Overview
CoreOS runs on almost any platform, including Vagrant, Amazon
EC2, QEMU/KVM, VMware and OpenStack and your own hardware.
CoreOS is a minimal operating system that supports popular
container systems out of the box. The operating system is designed
to be operated in clusters.
CoreOS doesn't ship a package manager — any software you would
like to use must run within a container.

8. CoreOS Overview
Features
● Automatic update
● btrfs
● Read only rootfs
● Writable overlay on /etc
● No classic package manager (apt, yum, dnf)
● Rollback

9. CoreOS Overview
Automatic Update
Omaha protocol (check-in/retrieval)
Omaha is the open-source version of Google Update, a program to
install requested software and keep it up to date.
The protocol is a fairly simple — it specifies sending HTTP POSTs
with XML data bodies for various events that happen during the
execution of an update.

10. CoreOS Overview
Update Request
● Active/Passive root partitions
● System running off read-only /usr on A
● OS update downloads to B, system reboot
when ready*
● In the event of boot failure, rollback

11. CoreOS Overview
Active/Passive root partitions
core@core-01 ~ $ sudo cgpt show /dev/sda3
start size part contents
270336 2097152 3 Label: "USR-A"
Type: Alias for coreos-rootfs
UUID: 7130C94A-213A-4E5A-8E26-6CCE9662F132
Attr: priority=1 tries=0 successful=1
core@core-01 ~ $ sudo cgpt show /dev/sda4
start size part contents
2367488 2097152 4 Label: "USR-B"
Type: Alias for coreos-rootfs
UUID: E03DD35C-7C2D-4A47-B3FE-27F15780A57C
Attr: priority=0 tries=0 successful=0

12. etcd
What is etcd?
etcd is an open-source distributed key value store
that provides shared configuration and service
discovery for CoreOS clusters. etcd runs on each
machine in a cluster and gracefully handles master
election during network partitions and the loss of
the current master.

13. etcd overview
What is etcd?

14. fleet
What is fleet?
fleet is a cluster manager that controls systemd at the cluster
level. To run your services in the cluster, you must submit regular
systemd units combined with a few fleet-specific properties.

15. fleet overview
What is fleet?
Fleet

16. Demo

17. Thanks!
Victor S. Recio
CEO and Founder at NerCore Inc,
@vsrecio
vrecio@nercore.com