1. Introduction to Docker
Demo on PHP Application deployment
Arun prasath S
April, 2014

2. 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
Development VM
QA server
Public Cloud
Disaster recovery
Contributor’s laptop
Production Servers
The ChallengeMultiplicityofStacksMultiplicityof
hardware
environments
Production Cluster
Customer Data Center
Doservicesandapps
interact
appropriately?
CanImigrate
smoothlyand
quickly?

3. Static website Web frontendUser DB Queue Analytics DB
Development
VM QA server
Public Cloud
Contributor’s
laptop
Docker is a shipping container system for codeMultiplicityofStacks
Multiplicityof
hardware
environments
Production
Cluster
Customer Data
Center
Doservicesandapps
interact
appropriately?
CanImigrate
smoothlyandquickly
…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…

4. 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 compatibility 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? That’s the power of Docker

5. 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 improves the speed and reliability of continuous deployment and continuous
integration systems
• Because the containers are so lightweight, address significant performance, costs,
deployment, and portability issues normally associated with VMs

6. Underlying Technology
• Namespaces (pid, net, ipc, mnt, uts)
• Control group
• UnionFS
Containers

7. App
A
Containers vs. VMs
Hypervisor (Type 2)
Host OS
Server
Guest
OS
Bins/
Libs
App
A’
Guest
OS
Bins/
Libs
App
B
Guest
OS
Bins/
Libs
AppA’
Docker
Host OS
Server
Bins/Libs
AppA
Bins/Libs
AppB
AppB’
AppB’
AppB’
VM
Container
Containers are isolated,
but share OS and, where
appropriate, bins/libraries
Guest
OS
Guest
OS
…result is significantly faster deployment,
much less overhead, easier migration,
faster restart

8. Why are Docker containers lightweight?
Bins/
Libs
App
A
Original App
(No OS to take
up space, resources,
or require restart)
AppΔ
Bins/
App
A
Bins/
Libs
App
A’
Guest
OS
Bins/
Libs
Modified App
Union file system allows
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

9. 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)

10. Why containers matter
Physical Containers Docker
Content Agnostic The same container can hold almost any
type of cargo
Can encapsulate any payload and its
dependencies
Hardware Agnostic Standard shape and interface allow same
container to move from ship to train to
semi-truck to warehouse to crane
without being modified or opened
Using operating system primitives (e.g. LXC)
can run consistently on virtually any
hardware—VMs, bare metal, openstack,
public IAAS, etc.—without modification
Content Isolation and
Interaction
No worry about anvils crushing bananas.
Containers can be stacked and shipped
together
Resource, network, and content isolation.
Avoids dependency hell
Automation Standard interfaces make it easy to
automate loading, unloading, moving,
etc.
Standard operations to run, start, stop,
commit, search, etc. Perfect for devops: CI,
CD, autoscaling, hybrid clouds
Highly efficient No opening or modification, quick to
move between waypoints
Lightweight, virtually no perf or start-up
penalty, quick to move and manipulate
Separation of duties Shipper worries about inside of box,
carrier worries about outside of box
Developer worries about code. Ops worries
about infrastructure.

11. Usecases

12. Demo – PHP application deployment
In this demo, I will show how to build a apache image from a
Dockerfile and deploy a PHP application which is present in an
external folder using custom configuration files.
Requirements:
Linux OS with Docker installed

13. Demo quick run :
1) Download this folder or files from Git - https://github.com/bingoarunprasath/php-app-docker.git
2) Now build a image for app deployment. From the folder downloaded, run the command
docker build -t bingoarunprasath/php .
3) Run the image by this command
docker run -i -t -d -p 80 -v /root/php-app/www:/var/www bingoarunprasath/php /bin/bash
4) You can run as many instances you want by running the above command
5) Run docker ps command to see the launched container. Note down the port number. (in my case 49172)
6) Now you can see your web application by visiting
http://<your-host-ip>:49172 or
http://<your-container-ip>:80
(You can view your container ID by docker ps and can view your container IP by docker inspect <container-ID>)

14. Demo explained
Folder structure
php-app
|______apache2files------apache2.conf
| |___ports.conf -> Apache configuration files
|
|______Dockerfile -> Docker file for building image
|
|______www/ -> PHP Application folder

15. Demo explained
Dockerfile
# Set the base image to Ubuntu
FROM ubuntu  Base image
RUN apt-get update
# File Author / Maintainer
MAINTAINER Example Arun
RUN apt-get install apache2 –y  Installed Apache
# Copy the configuration files from host
ADD apache2files/apache2.conf /etc/apache2/apache2.conf  Configuration files are copied during image build
ADD apache2files/ports.conf /etc/apache2/ports.conf
# Expose the default port
EXPOSE 80
#CMD ["/usr/sbin/apache2", "-D", "FOREGROUND"]  These lines are not working, when new instance starts, cant start apache
#CMD service apache2 start
RUN echo 'service apache2 start ' > /etc/bash.bashrc  Hence I started apache this way ,
# Set default container command
#ENTRYPOINT /bin/bash

16. Demo explained
Commands
1) Build image by using the Dockerfile in the current folder
$ docker build -t bingoarunprasath/php-app .
2) Run an instance from image build
$ docker run -i -t -d -p 80 -v /root/php-app/www:/var/www bingoarunprasath/php-app /bin/bash
-v /root/php-app/www:/var/www  PHP files are mounted during instance launch, Hence different apps can be mounted using the
same image