1. Introduction to Docker
Application-centric Virtualization for Linux
Ram Rao / April 5, 2016 1

2. Docker: Tool enabling Portable Applications through Light-weight Container-based Virtualization2

3. Agenda Introduction to Containers What is Docker? Docker Ecosystem
What problem does it solve?
Architecture
Docker Ecosystem
Getting Started with Docker
Docker Demonstration 3

4. Introduction to Containers
Light-weight Operating System Virtualization 4

5. Hypervisor-based Virtualization
Each OS sees its “own” hardware
Hypervisor mediates access to shared hardware resources
Isolates VMs from each other
Efficient CPU usage
This is a sample Two Pictures with Captions slide ideal for including two pictures with brief descriptive statements.
To Replace the Pictures on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing.
Virtual Machines 5

6. Container-based Virtualization
Single instance of OS
Unique per container:
File-systems
Users
IP addresses
Processes
Efficient memory usage
Container 1
Container 2
Container 3
This is a sample Two Pictures with Captions slide ideal for including two pictures with brief descriptive statements.
To Replace the Pictures on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing.
Container Engine
Operating System
Hardware 6

7. What is Container-virtualization?
Run multiple workloads in containers under single instance of OS
Each container is isolated from the others
Control resources (disk, memory, I/O etc) available to each controller
Differentiated levels of service to each container
Kernel modifications required to provide isolation and resource control
Examples of Container Virtualization:
LXC (standard in Linux)
Virtuozzo, OpenVZ (from Parallels), lmctfy (Google)
Solaris Zones, HP-UX Secure Resource Partitions 7

8. Linux Technologies enabling Containers
Name-space isolation
Process IDs
Network
Users
Mounts
Chroot: File-system isolation
C-groups: Resource limitation, prioritization, accounting
Memory, cpu, blkio, devices
Copy-on-write filesystem (AUFS) 8

9. Containers vs. Virtual Machines
Container Benefits
Container Limitations
Light-weight insulated environment
System supports many more VMs
Faster boot
Near native performance
Easier OS management
Cannot run disparate OSes (e.g. Linux and Windows)
Single kernel and patch level for all containers
Reboot requires taking down all containers
Should containers replace VMs?
It depends ...
Co-existence likely 9

10. So what is Docker?
Application-focused Containers 10

11. Docker: Application-centric containers
Technology developed by dotCloud.com, a PaaS provider
An open platform for developers and sysadmins to build, ship and run distributed applications
Enables apps to be quickly assembled from components and eliminates friction between development, QA and production environments
Allows faster shipping and running of apps, unchanged, on laptops, data-centers, VMs, and any cloud 11

12. The Matrix from Hell!
This is a sample Picture with Caption slide ideal for including a picture with a brief descriptive statement.
To Replace the Picture on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing. 12

13. Shipping: Another Matrix from Hell!
This is a sample Picture with Caption slide ideal for including a picture with a brief descriptive statement.
To Replace the Picture on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing. 13

14. Shipping Solution: Universal Containers
This is a sample Picture with Caption slide ideal for including a picture with a brief descriptive statement.
To Replace the Picture on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing. 14

15. This is a sample Picture with Caption slide ideal for including a picture with a brief descriptive statement.
To Replace the Picture on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing. 15

16. How does Docker differ from LXC Containers?
Technology providing light-weight Linux containers
Provides an entire Linux virtual environment
Typically long lifetime
Single application virtualization engine based on LXC containers..
Base OS pared down for a single application
Does not have a proper init or services, daemons, syslogs, cron etc.
Typically short lifetime; very fast startup
Focus is on portability across multiple machines and environments using standard containers.
Provides a registry where users can push/pull images
Layering eases application composition 16

17. Docker Architecture
This is a sample Picture with Caption slide ideal for including a picture with a brief descriptive statement.
To Replace the Picture on this Sample Slide (this applies to all slides in this template that contain replaceable pictures)
Select the sample picture and press Delete. Click the icon inside the shape to open the Insert Picture dialog box. Navigate to the location where the picture is stored, select desired picture and click on the Insert button to fit the image proportionally within the shape.
Note: Do not right-click the image to change the picture inside the picture placeholder. This will change the frame size of the picture placeholder. Instead, follow the steps outlined above.
Tip: use the Crop tool to reposition a picture within a placeholder. From the Picture Tools Format tab on the ribbon, click the Crop button. Click and drag the picture within the placeholder to reposition. To scale the picture within the placeholder (while Crop is active), grab a round corner handle and drag to resize. Hold Shift key to constrain picture aspect ratio when resizing. 17

18. The Docker Ecosystem 18

19. Docker Eco-system 19

20. Docker Infrastructure Availability
Linux Distributions:
RHEL 7.x, CentOS 7.x, Ubuntu , SLES 12
Container-specific minimal OSes: CoreOS, Project Atomic, Photon
On non-Linux OSes (Windows, OSX): Docker Toolbox
In the cloud:
Google Cloud, Amazon AWS, Microsoft Azure
OpenStack integration
Future:
Docker engine integration into Windows Server 20

21. Docker and Microsoft Today: Future:
- Azure + Linux VMs + Docker (running Linux containers)
- Windows docker client (in Docker v1.6)
Future:
- Windows server with Hyper-V Containers (docker engine running Windows containers)
- Azure with Hyper-V Containers (docker engine running Windows containers)
- Nano Server as minimal container image for Cloud apps (more efficient, smaller attack area)
See here:
Integration with Keystone in progress
Other projects?
Solum?
Magnum?
Why Docker + OpenStack?
Alternative to VMs within OpenStack
Easier deployment of OpenStack itself
Cross cloud application deployment
At OpenStack Summit we hope to show:
Building and testing an application from source
Running on a laptop
Running it, without modification or noticeable downtime, on a public cloud
Running it, without modification or noticeable downtime, on an openstack cluster
Doing all of the above using Nova and Horizon
Many ongoing Docker projects:
Nova Docker hypervisor driver – but not a natural fit for containers
Docker heat plugin – allows to pilot containers within a virtual machine running under OpenStack
Dockenstack - DevStack (OpenStack dev+test environment) within a Docker container
Magnum (containers as a service) and Solum (PaaS) projects in OpenStack
Nova compute + ironic + bare-metal + Docker
Docker-in-Docker (Kubernetes, Mesos, Heat, CloudFoundry, Magnum controlled ….)
Nova doesn’t…
Link container networks
Pass environment variables
Specify working directories
Create docker-volumes
Share docker-volumes between containers
Arbitrary commands
Arbitrary command-arguments
Pass devices
Nova is a machine abstraction, not a process one.
Docker doesn’t…
• Support mounting devices (unprivileged)
• Live-migration is future-speak
• Boot from block devices (natively - it’s possible…)
• Support Glance natively
• PCI pass-through
In Havana & IceHouse releases:
• docker-registry worked as a proxy
• Users had to upload through docker-registry.
• docker pulls images through the docker-registry proxy
Just enough Docker:
docker-registry worked as a proxy
• Users had to upload through
docker-registry.
• docker pulls images through the
docker-registry proxy
(at-release)
Havana & Icehouse
Image Management
• Glance was only used to provide
visibility of Docker images for Nova.
• Users could not upload through
Glance directly
• Making that work would require a
special procedure for glance uploads.
so… we took out the docker-registry instead.
Just Enough Docker
J• A subset of Nova features…
• A subset of Docker features…
• Enough for Nova to allow running Docker-in-Docker.
• DinD retains most performance benefits of Docker.
• DinD is Docker and everything you love about Docker.
2018/9/15 21

22. Docker: Linux and Windows
See here:
Integration with Keystone in progress
Other projects?
Solum?
Magnum?
Why Docker + OpenStack?
Alternative to VMs within OpenStack
Easier deployment of OpenStack itself
Cross cloud application deployment
At OpenStack Summit we hope to show:
Building and testing an application from source
Running on a laptop
Running it, without modification or noticeable downtime, on a public cloud
Running it, without modification or noticeable downtime, on an openstack cluster
Doing all of the above using Nova and Horizon
Many ongoing Docker projects:
Nova Docker hypervisor driver – but not a natural fit for containers
Docker heat plugin – allows to pilot containers within a virtual machine running under OpenStack
Dockenstack - DevStack (OpenStack dev+test environment) within a Docker container
Magnum (containers as a service) and Solum (PaaS) projects in OpenStack
Nova compute + ironic + bare-metal + Docker
Docker-in-Docker (Kubernetes, Mesos, Heat, CloudFoundry, Magnum controlled ….)
Nova doesn’t…
Link container networks
Pass environment variables
Specify working directories
Create docker-volumes
Share docker-volumes between containers
Arbitrary commands
Arbitrary command-arguments
Pass devices
Nova is a machine abstraction, not a process one.
Docker doesn’t…
• Support mounting devices (unprivileged)
• Live-migration is future-speak
• Boot from block devices (natively - it’s possible…)
• Support Glance natively
• PCI pass-through
In Havana & IceHouse releases:
• docker-registry worked as a proxy
• Users had to upload through docker-registry.
• docker pulls images through the docker-registry proxy
Just enough Docker:
docker-registry worked as a proxy
• Users had to upload through
docker-registry.
• docker pulls images through the
docker-registry proxy
(at-release)
Havana & Icehouse
Image Management
• Glance was only used to provide
visibility of Docker images for Nova.
• Users could not upload through
Glance directly
• Making that work would require a
special procedure for glance uploads.
so… we took out the docker-registry instead.
Just Enough Docker
J• A subset of Nova features…
• A subset of Docker features…
• Enough for Nova to allow running Docker-in-Docker.
• DinD retains most performance benefits of Docker.
• DinD is Docker and everything you love about Docker.
2018/9/15 22

23. Docker Tools GUI: Shipyard, Docker-UI Docker PAAS: Dokku, Flynn, Deis
Orchestration:
CoreOS, Panamax, Kubernetes 23

24. Where is Docker being used?HP
IT hosts a docker container registry
Directory app etc.
eBay Now
Spotify
Google lmctfy
Provide all their services using containers (Search, Mail, Docs, etc.)
Start over 3000 containers/sec (over 2B containers/week) 24

25. Learning Docker Use Linux Distros that have Docker packages:
Ubuntu or later
CentOS 7.x, …
Run on Windows, OSX by installing Docker Toolbox or boot2docker
Docker User Guide: 25

26. Docker Demonstration 26

27. Docker: Tool enabling Portable Applications through Light-weight Container-based Virtualization27

28. Questions? 28