Short overview of CoreOS

1. CoreOS
warehouse-scaled computing
Nikolay Yurin, DevOps Engineer

2. What is CoreOS?
● Minimal operating system
● Clustered by default
● Services as Docker containers
● Safe updating system

3. Profit?
● Static VM pool - multiple services
VM_1
VM_2 VM_3
DB
App
DB
VM_1
App
DB
VM_2 VM_3

4. Supported platforms
● Amazon EC2
● QEMU / KVM
● VirtualBox
● VMware
● OpenStack
● Bare-metal

5. CoreOS components
● etcd
● systemd
● docker

6. etcd
Distributed key-value
storage for shared
configurations

7. systemd
[Unit]
Description=My Apache Frontend
After=docker.service
Requires=docker.service
[Service]
ExecStart=/usr/bin/docker run --name apache -p 80:80 coreos/apache /usr/sbin/apache2ctl -D
FOREGROUND
ExecStop=/usr/bin/docker stop apache
[X-Fleet]
X-Conflicts=apache.*.service

8. docker
● Container manager
● Automatically runs
on every CoreOS
machine
● Integrated with etcd

9. Fleet - manage cluster with ease
● Deploy docker containers on arbitrary hosts
in a cluster
● Discover machines running in the cluster
● Distribute services across a cluster using
machine-level anti-affinity

10. Demo

11. How to learn more?
https://coreos.com/using-coreos

12. Q&A
Twitter/Github/Facebook: @yurinnick