Intro to coreOS linux distributions and how it can be used to run docker based workloads in the cloud. coreOS instances can be started in a cloudstack cloud, it makes use of cloud-init basics to

1. Kubernetes on CloudStack
with coreOS
Sebastien Goasguen
@sebgoa
Nov 11th 2014
London, England

2. Who am
I ?
• Apache CloudStack and
licloud committer +
PMC member
• Looking at techs and
how they work together
• Half dev, half
community manager, +
half event planner

3. Today’s
talk

4. Ugly slide #1
Docker
containers
Docker
containers
Docker
containers
KK** Docker KK** KK**
containers
Docker
containers
ccoorreeOOSS ccoorreeOOSS ccoorreeOOSS
Cloud (e.g CloudStack Cloud (e.g CloudStack b baasseedd = = e exxoossccaalele))
Docker
containers
API calls to
Kubernetes API

5. • Linux container (LXC +)
• Application deployment
• PaaS
• Portability
• Image sharing via
DockerHub
• Ease of packaging
applications

6. Building docker images
Fair use from http://blog.octo.com/en/docker-registry-first-steps/

7. + config mgmt

8. CoreOS
• Linux distribution
• Rolling upgrades
• Minimal OS
• Docker support
• etcd and fleet tools
to manage distributed
applications based on
containers.
• Cloud-init support
• Systemd units

9. coreOS “OEM”
http://github.com/coreos/coreos-overlay

10. coreOS “OEM”
http://github.com/coreos/coreos-overlay

11. The cloudinit magic

12. CoreOS clustering
• etcd HA key value store
– Raft election algorithm
– Writes when majority in cluster has committed
update
– e.g 5 nodes, tolerates 2 nodes failure
• fleet distributed init system (schedules
systemd units in a cluster)
– Submits systemd units cluster wide
– Affinity, anti-affinity, global “scheduling”

13. “coreOS is the first cloud OS dedicated to
docker based application workloads”

14. “Where are you going to run coreOS ?”

15. IaaS
Landscape

16. CloudStack clouds

17. Data Center Orchestrator
AAPPII ((EECC22 && CCSS)) SSeellff--sseerrvviiccee PPoorrttaall MMeetteerriinngg
IImmaaggee MMggmmtt.. DDaasshhbbooaarrdd IIddeennttiittyy MMggmmtt..
LLooaadd BBaallaanncceerrss FFWWss && VVPPNNss
SSttoorraaggee CCoommppuuttee NNeettwwoorrkk

18. • IaaS Public cloud
• Switzerland based
• Apache CloudStack
• Security groups, ssh key
pairs
• Offers coreOS
templates (+ Debian,
ubuntu, CentOS and
even Windows)

19. CoreOS on exoscale

20. Starting containers
#cloud-config
coreos:
units:
- name: docker.service
command: start
- name: es.service
command: start
content: |
[Unit]
After=docker.service
Requires=docker.service
Description=starts ElasticSearch container
[Service]
TimeoutStartSec=0
ExecStartPre=/usr/bin/docker pull dockerfile/elasticsearch
ExecStart=/usr/bin/docker run -d -p 9200:9200 -p 9300:9300
dockerfile/elasticsearch

21. Kubernetes
• Docker application
orchestration
• Google GCE, rackspace,
Azure providers
• Deployable on CoreOS
• Container replication
• HA services

22. Kubernetes API

23. Kubernetes {
"id": "redis-master-2",
"kind": "Pod",
"apiVersion": "v1beta1",
"desiredState": {
"manifest": {
"version": "v1beta1",
"id": "redis-master-2",
"containers": [{
"name": "master",
"image": "dockerfile/redis",
"ports": [{
"containerPort": 6379,
"hostPort": 6379
…
"labels": {
"name": "redis-master"
}
}

24. Kubernetes
on CloudStack
• Find a CloudStack cloud that supports CoreOS
• Then use:
https://github.com/runseb/kubernetes-exoscale
• Libcloud to start nodes with coreOS template
• User data to pass cloud-configs
• Then start Kube* Service units with fleet

25. CClolouudd A APPI I
Libcloud startup
scripts
Etcd cluster
5 nodes
Etcd cluster
5 nodes
Discovery service to
Discovery service to
bootstrap
bootstrap
PR welcome:
https://github.com/runseb/kubernetes-Kubernetes cluster
Kubernetes cluster
5 nodes
5 nodes
Start Kube* services via fleet
Run guestbook example
Start Kube* services via fleet
Run guestbook example

26. Docker
container
Docker
container
Docker
container
KK** Docker KK** KK**
container
Docker
container
ccoorreeOOSS ccoorreeOOSS ccoorreeOOSS
Cloud (e.g CloudStack Cloud (e.g CloudStack b baasseedd = = e exxoossccaalele))
Docker
container
API calls to
Kubernetes API

27. Questions and Thanks
Sebastien Goasguen
@sebgoa