Giant Swarm is a company based in Cologne, Germany that builds services on top of CoreOS. CoreOS is a minimal operating system optimized for running containers, with automatic updates and cluster management capabilities. It uses tools like etcd for service discovery and configuration management, Fleet for orchestrating containers across clusters, and Locksmith for coordinated container reboots during OS updates.

1. Timo Derstappen
@teemow

2. Giant Swarm
● Simple Service Orchestration
● Based in Cologne, Germany
● Built on top of CoreOS
http://giantswarm.io

3. ● Minimal OS to host your containers
● Automatic Updates
● Cluster Management
● Service Discovery

4. CoreOS 101
● Minimal Gentoo
● PXE, OpenStack, AWS, GCE, Vagrant
● Systemd, btrfs
● Read-only rootfs (writable overlay)

5. CoreOS own tools
● Etcd
● Fleet
● Locksmith
● Cloud-config
github.com/coreos

6. Etcd
● Highly available K/V store
● Basis for
○ Configuration management
○ Service Discovery
● Raft consensus algorithm
● REST Interface

7. Discovery API
$ curl https://discovery.etcd.io/new
https://discovery.etcd.
io/463c1435f9f63c952e0899b1f459c0fe

8. Cloud Config
● Initialization of your instances
● Configure etcd, fleet, locksmith

9. Configure your cluster
#cloud-config
coreos:
etcd:
discovery: https://discovery.etcd.io/<token>
addr: $private_ipv4:4001
peer-addr: $private_ipv4:7001

10. Locksmith
● Reboot strategies for CoreOS updates
● Uses etcd for distributed locks

11. Fleet
● Fleet is systemd for the cluster
● Uses etcd
● CLI and API to start your containers

12. Fleet Scheduler
● Simple (eg. based on Metadata)
● But resolves service dependencies!
● More to come (eg. based on available
resources)

13. Unit file
[Unit]
Description=A Redis Server
[Service]
TimeoutStartSec=0
EnvironmentFile=/etc/environment
Environment="IMAGE=teemow/redis"
ExecStartPre=/usr/bin/docker pull $IMAGE
ExecStart=/bin/bash -c "exec /usr/bin/docker run --rm -p
$COREOS_PRIVATE_IPV4::6379 --name %n $IMAGE"
ExecStop=/usr/bin/docker stop %n

14. Launch a service
# start
fleetctl start redis.service
# status
fleetctl list-units
fleetctl status redis.service
fleetctl journal redis.service
# stop
fleetctl stop redis.service
fleetctl destroy redis.service

15. Release it!
● Load Balancer
● App
● Database

16. Sidekick
● Keep
configuration out
of your app

17. Ambassador
● Reverse proxy for
your service
● Keep service
discovery out of
your app

18. CoreOS
● Great foundation to create flexible distributed
infrastructures
● Unix philosophy

19. Thanks for listening!
Timo Derstappen
@teemow
http://giantswarm.io