CoreOS is a minimal operating system designed for clustered, containerized workloads where services run as Docker containers and updates are handled safely. It supports running workloads on platforms like EC2, KVM, VirtualBox and OpenStack. Key CoreOS components include etcd for distributed configuration storage, systemd for service management, Docker for containers, and Fleet for cluster management and service deployment across nodes.

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