Storage

& Kubernetes

for everyone

Ryan Wallner

Technical Evangelist, ClusterHQ

@RyanWallner : ryan@clusterhq.com

Ryan Wallner

Technical Evangelist

@ryanwallner

Avid outdoorsman, works in tech.

Goals for this Talk

• ​​Containers / Persistence
• Volumes / Docker Volumes
• Kubernetes Volumes
• Demo
• Q/A

Container

• Container = Process and Resource Isolation
• Linux Process (think of as light weight app vm)
• Does not need a hypervisor, shares a linux kernel
• Enables new architectures such as Microservices

"Stateful" Container

• Secrets - public/private keys, password, etc
• Data - databases, sharded, clustered etc.
• Logs - to collect support bundles, run analytics for data mining, etc. 

"Stateless" Container

• Nothing to Disk
• Web Front-End
• Can stop and start as many containers as you like
• How http is stateless
• Container is ephemeral

Container Volumes

https://clusterhq.com/2015/12/09/difference-docker-volumes-flocker-volumes/ 

• Inside the container
  • ​docker image
  • ​ephemeral
• Outside UFS
  • Docker (-v /myvol)
  • emptyDir (k8s)
• Host Filesystem
  • Docker bind mounts (-v /tmp:/tmp)
  • hostPath (k8s)
• Shared/External
  • Docker --volume-driver= 
  • Flocker (k8s,docker,mesos)
  • gcePersistentDisk (k8s)

Kubernetes Volumes

• emtpyDir
• hostPath
• gcePersistentDisk
• awsElasticBlockStore
• nfs
• iscsi
• flocker
• rbd
• glusterfs
• secret
• persistentVolumeClaim
• gitrepo
• downwardAPI

http://kubernetes.io/v1.1/docs/user-guide/volumes.html

Kubernetes Volumes

• emtpyDir
  • ​temporary
• hostPath
  • ​bind mounts
  • on host, in container
  • doesn't scale
• gcePersistentDisk
  • ​standard or SSD
  • can be RO across PODS
• awsElasticBlockStore
  • ​EBS for you POD
• nfs
  • ​Share must exist
  • sync-and-share usecases
• gitrepo
  • ​auto clone repo to POD
• downwardAPI
  • ​writes requested data to text files in POD

http://kubernetes.io/v1.1/docs/user-guide/volumes.html

Kubernetes

FLocker Volumes

• Flocker​ (https://docs.clusterhq.com/en/latest/)

  • Manages - data volume lifecycle

  • Enables - Container + volume: atomic

  • Migrates - data volumes across hosts

  • Works - using container orchestrators 

https://docs.clusterhq.com/en/1.9.0/introduction/flocker-supports.html#list-of-storage-backends

https://github.com/kubernetes/kubernetes/tree/master/examples/flocker​

• Pluggable​

  • Amazon EBS

  • EMC

  • VMWare

  • NetApp

  • Huawei

  • OpenStack Cinder

  • Dell

  • Hedvig

  • Saratoga Speed

  • Nexenta

  • Ceph 

Demo

Orchestration

Scheduling

Networking

Service Discovery

Purpose Built OS

Security

Built-in Tooling

(docker, etcd, flannel, fleet)

Docker Volume Management

 Automation

Mobility

Resiliency

Flexibility

1st Class Volumes

Reliability (mostly)

Public Cloud

Availability

What's In the stack?

https://github.com/wallnerryan/kube-aws-flocker

Example Application

http://kubernetes.io/v1.1/examples/guestbook-go/README.html

• Partial vs Full resynchronization- http://redis.io/topics/replication
• redis persistance - http://redis.io/topics/persistence

high availability

THANK YOU

Thanks to Digital Ocean

www.clusterhq.com

www.clusterhq.com/blog

We're Hiring!

www.clusterhq.com/careers/

@RyanWallner

Ryan@clusterhq.com

@clusterhq

More Info.