There are right and wrong ways to use containers with persistent applications. Lucky for you, doing it the right way is much easier nowadays with Docker Volume Plugins. This talk will focus on doing some basic education including mostly live demos to show how you can take advantage of these new capabilities for expanding how you leverage containers.

1. Discovering+Docker+
Volume+Plugins+and+
Apps+using+VirtualBox
Clint&Kitson&*&Developer&
Advocate&Leader
emccode.github.io

2. descrip(on
There%are%right%and%wrong%ways%to%use%containers%with%persistent%
applica4ons.%Lucky%for%you,%doing%it%the%right%way%is%much%easier%
nowadays%with%Docker%Volume%Plugins.%This%talk%will%focus%on%doing%
some%basic%educa4on%including%mostly%live%demos%to%show%how%you%
can%take%advantage%of%these%new%capabili4es%for%expanding%how%
you%leverage%containers.

3. Agenda
• Docker(Volume(Plugin(overview
• Volume(Plugins(with(VirtualBox(in(ac9on
• Inves9ga9ng(applica9ons(and(running(with(Volume(Plugin
• Thinking(about(availability
• Performing(failAover(of(a(container(to(another(container(host

4. Situa&on/Problem
• When&I&run&a&persistent&applica1on&in&a&container,&where&does&
my&data&get&stored?
• Possibly&a&data&volume
• Possibly&container&volume
• Possibly&an&exis1ng&private&mounted&volume&from&networked&
storage
• ..&howto&build&a&snowflake
• Container&hosts&should&be&immutable

5. Enter&Docker&Extensibility
• Volume
• Network
• Authoriza2on
• Composable8and8sustainable
• Consumed8solely8through8Docker8API
• Up8to8consuming8ecoAsystem8to8leverage8func2onality,8ie.8
container8schedulers

6. What%are%Docker%Volume%
Plugins
• Drama&cally*simplifies*external*storage*
for*usage*with*containers
• Service*that*runs*alongside*Docker*
daemon*receiving*Plugin*requests
• Extensible*storage*orchestra&on
• Lunch*is*ready*at*/var/lib/
plugin/volumes/vol1/data
• Serves*requests*for*Volume*Create/
Remove/Mount/Unmount/Path

7. How$do$we$play?
• VirtualBox,can,be,used,similar,to,
explore
• VirtualBox,is,popular,and,works,well,
on,laptops
• Provides,shared,storage,pla;orm,
through,Virtual,Media
• or,GCE,,AWS,EC2,,Openstack,Cinder,,
EMC,ScaleIO/XtremIO/Isilon/VMAX
• or,other,Volume,Plugins
• MulIple,container,hosts,(VMs),to,
ensure,failover,and,immutability

8. Typical(Install(and(Configure
• Install
curl -sSL https://dl.bintray.com/emccode/rexray/install | sh -
• /etc/rexray/config.yml
rexray:
logLevel: warn
storageDrivers:
- virtualbox
mount:
volume:
preempt: false
virtualbox:
endpoint: http://10.0.2.2:18083
tls: false
volumePath: "/Users/clintonkitson/Repos/vagrant-rexray/Volumes"
controllerName: SATA

9. Super&Simple&Example&using&
Vagrant&and&VirtualBox
• Requires
• Vagrant
• VirtualBox25.0.10+
• VBoxManage setproperty
websrvauthlibrary null
• vboxwebsrv -H 0.0.0.0 -v -b

10. Vagrant'example
git clone https://github.com/jonasrosland/vagrant-rexray
cd vagrant-rexray
vagrant up
vagrant ssh rexray-1

11. Discover)REX-Ray)and)
VirtulBox)on)rexray-1
sudo su
rexray
rexray volume --help
rexray volume ls
rexray volume create --volumename=testing --size=1
rexray volume mount --volumename=testing
ls /var/lib/rexray/volumes/testing/data
rexray volume unmount --volumename=testing
rexray stop
rexray start

12. docker'volume'create'.'
rexray.1
docker volume
docker volume create
--driver=rexray --name=meetup1 --opt=size=2
docker volume ls

13. docker'run'with'busybox
docker run -ti
--volume-driver=rexray -v meetup1:/meetup1
busybox
df /meetup1
touch /meetup1/hello
exit

14. docker'run'to'verify'with'busybox
docker run -ti
--volume-driver=busybox -v meetup1:/meetup1
busybox
ls /meetup1
exit

15. docker'run'with'sharing'
volume
docker run -tid --name=container1
--volume-driver=rexray -v meetup1:/meetup1 busybox
docker run -ti --volumes-from=container1 busybox
ls /meetup1
exit
docker exec container1 ls /meetup1
docker stop container1

16. Discovering+Volumes+and+Container+Images
• REX%Ray(Docs(on(Applica2ons
• Dockerfile(includes(a(VOLUME(instruc2on
• VOLUME(["/data"]
• Up(to(container(image(maintainer(to(properly(designate(
appropriate(loca2on(of(persistent(data
• Makes(a(container(workload(portable
• Enables(immutable(hosts

17. Discovering+Apps+and+Volumes+using+postgres
• postgres)on)docker)hub
• Dockerfile)for)postgres)9.5
• VOLUME)/var/lib/postgresql/data

18. running&postgres&,&internal&data&volume
docker run --name some-postgres
-e POSTGRES_PASSWORD=mysecretpassword -d
postgres
docker rm -f some-postgres

19. running&postgres&,&external&data&volume
docker volume create
--driver=rexray --name=pdata --opt=size=3
docker run --name some-postgres
-e POSTGRES_PASSWORD=mysecretpassword -d
--volume-driver=rexray -v pdata:/var/lib/postgresql/data
postgres
ls /var/lib/rexray/volumes/pdata/data
docker logs some-postgres
exit

20. try$a$failover$,$on$rexray,2
vagrant ssh rexray-2
sudo su
docker run --name some-postgres
-e POSTGRES_PASSWORD=mysecretpassword -d
--volume-driver=rexray -v pdata:/var/lib/postgresql/data
postgres

21. Thinking'About'Availability
• Always(sharing(isn't(the(answer
• Safety(first(for(ext4/xfs
• Failure(scenarios?
• Container(dies?
• Container(run>me(borks?
• Kernel(problems?
• Host(unresponsive?
• ..(volumes(are(typically(aGached(and(
locked(to(hosts

22. turn%on%volume%mount%pre,emp-on
• vi$/etc/rexray/config.yml
• set$rexray.volume.mount.preempt: true
• rexray$stop
• rexray$start

23. do#a#failover#+#on#rexray+2
docker run --name some-postgres
-e POSTGRES_PASSWORD=mysecretpassword -d
--volume-driver=rexray -v data:/var/lib/postgresql/data
postgres

24. Summary
• Volume(plugins(are(great
• Keep(container(hosts(immutable
• Persistent(volumes(can(be(orchestrated(for(containers
• Container(images(with(volumes(specified(are(easy(to(make(
persistent

25. EMC${code}$+$emccode.github.io
• Looking(for(folks(that(are(passionate(about(Containers,(Open(
Source,(and(DevOps
• REX?Ray
• RackHD
• mesos?module?dvdi
• OSS(ContribuCon(?(Docker,(Mesos,(others

26. THANK&YOU
emccode.github.io