2. Contents
• Introduction to Docker, Containers, and the Matrix from Hell
• The Challenge, the Matrix From Hell
• Why Developers Care
• Technical Explanation
• Docker Compose
• Docker Machine
• Docker Swarm
• Learn More
3. Static website
Web frontend
User DB Queue
Analytics DB
Background workers API endpoint
nginx 1.5 + modsecurity +
openssl + bootstrap 2
postgresql + pgv8 + v8
hadoop + hive + thrift + OpenJDK
Ruby + Rails + sass + Unicorn
Redis + redis-sentinel
Python 3.0 + celery + pyredis + libcurl
+ ffmpeg + libopencv + nodejs +
phantomjs
Python 2.7 + Flask + pyredis + celery +
psycopg + postgresql-client
DevelopmentVM
QA server
Public Cloud
Disaster recovery
Contributor’s laptopProduction Servers
The Challenge
Production Cluster
Customer Data Center
4. The Matrix From Hell
Static website ? ? ? ? ? ? ?
Web frontend ? ? ? ? ? ? ?
Background workers ? ? ? ? ? ? ?
User DB ? ? ? ? ? ? ?
Analytics DB ? ? ? ? ? ? ?
Queue ? ? ? ? ? ? ?
DevVM QA Server
Single Prod
Server
Onsite
Cluster
Public
Cloud
Contributor
laptop
Customer
Servers
7. Solution: Intermodal Shipping Container
…in between, can be loaded and
unloaded, stacked, transported
efficiently over long distances, and
transferred from one mode of
transport to another
A standard container that is
loaded with virtually any goods,
and stays sealed until it reaches
final delivery.
8. Static website Web frontendUser DB Queue Analytics DB
DevelopmentVM QA server Public Cloud Contributor’s laptop
Docker is a shipping container system for code
Production
Cluster
Customer
Data Center
…that can be manipulated using
standard operations and run
consistently on virtually any hardware
platform
An engine that enables any
payload to be encapsulated as a
lightweight, portable, self-
sufficient container…
9. Static website
Web frontend
Background workers
User DB
Analytics DB
Queue
Development
VM
QA Server
Single Prod
Server
Onsite
Cluster
Public Cloud
Contributor’s
laptop
Customer
Servers
Docker eliminates the matrix from Hell
10. I am at customer and am
having trouble running our web
application
19. Why Developers Care?
Build once…finally run anywhere
• A clean, safe, hygienic and portable runtime environment for your app.
• No worries about missing dependencies, packages and other pain points
during subsequent deployments
• Run each app in its own isolated container, so you can run various
versions of libraries and other dependencies for each app without worrying
• Automate testing, integration, packaging..anything you can script
• Reduce/eliminate concerns about compatibly on different platforms, either
your own or your customers.
• Cheap, zero-penalty containers to deploy services? A VM without the
overhead of a VM? Instant replay and reset of image snapshots? Thats
the power fo Docker.
20. Why DevOps Cares?
Configure Once…Run Anything
• Make the entire lifecycle more efficient, consistent, and repeatable
• Increase the quality of code produced by developers.
• Eliminate inconsistencies between development, test, production, and
customer environments.
• Support segregation of duties.
• Significantly improve the speed and reliability of continuous
deployment and integration systems.
• Because the containers are so lightweight, address significant
performance, costs, deployment, and portability issues normally
associated with VMs.
21. Why it works—separation of concerns
Dan the Developer
• Worries about whats “inside”
the container
• His code
• His Libraries
• His Package Manager
• His Apps
• His Data
Oscar the Ops Guy
• Worries about what’s “outside”
the container
• Logging
• Remote Access
• Monitoring
• Network Config
• All Containers, start, stop,
copy, attach, migrate, etc. the
same way
22. Why it Works?
• Run everywhere
• Regardless of kernel version
• Regardless of host distort
• Physical or virtual, cloud or not
• Run anything
• If it can run on the host, it can run in the container
• i.e. if it can run on a linux kernel, it can run.
• High Level - Its a lightweight VM
• Own process space
• Own network interface
• Can run stuff as root
• Can have its own /sbin/init (different from host)
23. Why are Docker containers lightweight?
Bins/
Libs
App
A
Original App
(No OS to take
up space, resources,
or require restart)
AppΔ
App
A
Bins/
Libs
App
A’
Bins/
Libs
Modified
App
Copy on write capabilities
allow
us to only save the diffs
Between container A and
container
A’VMs
Every app, every copy of an
app, and every slight modification
of the app requires a new virtual server
App
A
Guest
OS
Bins/
Libs
Copy of
App
No OS. Can
Share bins/libs
App
A
Guest
OS
Guest
OS
VMs Containers
24. What are the basics of the Docker system?
Source Code
Repository
Dockerfile
For
A
Docker Engine
Docker
Container
Image
Registry
Build
Docker
Host 2 OS (Linux)
ContainerA
ContainerB
ContainerC
ContainerA
Push
Search
Pull
Run
Host 1 OS (Linux)
26. Multiple Linked Containers
• Containers can be linked together
• Sets environment values and host entries so containers
can speak to each other over a local network.
docker pull redis:latest
docker build -t web .
docker run -d --name=db redis:latest redis-server --appendonly yes
docker run -d --name=web --link:db:db -p 5000:5000 -v `pwd`:/code python
app.py
27. This is still too hard, typing
commands with lots of
arguments takes too long.
28. Docker Compose
• Multi Container Applications are a Hassle
• Build an Image from Dockerfiles
• Pull images from Docker Hub or a private registry
• Configure, start and Stop containers
docker pull redis:latest
docker build -t web .
docker run -d --name=db redis:latest redis-server --appendonly yes
docker run -d --name=web --link:db:db -p 5000:5000 -v `pwd`:/code python
app.py
29. Docker Compose
• Docker Compose gets your multi container app running
in one command
docker-compose up
web:
build: .
ports:
- "5000:5000"
volumes:
- .:/code
links:
- redis
redis:
image: redis
32. Docker Machine
• Single Binary to create a remote Docker host and setup
the TLS communication with your local docker client
• Automates TLS setup for accessing remote docker
daemon
• Manage multiple machines in different clouds at the
same time
33. Cloud Ready Deployment
• Docker Machine includes drivers for
• Virtual Box
• VM Ware
• Amazon EC2
• Google Compute
• Digital Ocean
• Many More…
34. Creating a local Docker Host
$:docker-machine create --driver virtualbox --virtualbox-memory "8000" dev
$:docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM
dev virtualbox Running tcp://192.168.99.100:2376
dockerbig * amazonec2 Running tcp://10.0.1.10:2376
$:docker-machine env dev
export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.100:2376"
export DOCKER_CERT_PATH="/Users/jellin/.docker/machine/machines/dev"
export DOCKER_MACHINE_NAME=“dev"
# Run this command to configure your shell:
# eval "$(docker-machine env dev)"
35. Docker Swarm
• Native Clustering for Docker hosts
• Dynamically spread container load among multiple
hosts.
• multiple strategies available for ranking node utilization
and availability
• Can integrate with docker machine and api’s such as
Dokku to dynamically allocate additional Docker hosts
as needed.
• Swarm Coordinator run as a container
