Introduction to Docker Demo on PHP Application deployment

Arun prasath SApril, 2014

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 ChallengeM

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Production Cluster

Customer Data Center

Do services and apps

interact appropriately?

Can I migrate

smoothly and quickly?

Static website Web frontend User DB Queue Analytics DB

Development VM QA server Public Cloud

Contributor’s laptop

Docker is a shipping container system for code M

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…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…

Why Developers CareBuild 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

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

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

Containers

AppA

Containers vs. VMs

Hypervisor (Type 2)

Host OS

Server

GuestOS

Bins/Libs

AppA’

GuestOS

Bins/Libs

AppB

GuestOS

Bins/Libs

App A’

Docker

Host OS

Server

Bins/Libs

App ABins/Libs

App B

App B’

App B’

App B’VM

Container

Containers are isolated,but share OS and, whereappropriate, bins/libraries

GuestOS

GuestOS

…result is significantly faster deployment, much less overhead, easier migration, faster restart

Why are Docker containers lightweight?

Bins/Libs

AppA

Original App(No OS to takeup space, resources,or require restart)

App Δ

Bins/

AppA

Bins/Libs

AppA’

GuestOS

Bins/Libs

Modified App

Union file system allowsus to only save the diffsBetween container A and containerA’

VMsEvery app, every copy of anapp, and every slight modificationof the app requires a new virtual server

AppA

GuestOS

Bins/Libs

Copy ofApp

No OS. Can Share bins/libs

AppA

GuestOS

GuestOS

VMs Containers

What are the basics of the Docker system?

Source Code Repository

DockerfileFor

A

Docker Engine

DockerContainer

Image Registry

Build

Docker

Host 2 OS (Linux)

Container A

Container B

Container C

Container A

Push

Search Pull

Run

Host 1 OS (Linux)

Why containers matterPhysical 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.

Usecases

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

Demo quick run :

1) Download this folder or files from Git - https://github.com/bingoarunprasath/php-app-docker.git2) 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/bash4) You can run as many instances you want by running the above command5) 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 orhttp://<your-container-ip>:80

(You can view your container ID by docker ps and can view your container IP by docker inspect <container-ID>)

php-app.rar

Demo explained Folder structure

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

Demo explained Dockerfile# Set the base image to UbuntuFROM ubuntu Base imageRUN apt-get update# File Author / MaintainerMAINTAINER Example ArunRUN 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 buildADD apache2files/ports.conf /etc/apache2/ports.conf# Expose the default portEXPOSE 80#CMD ["/usr/sbin/apache2", "-D", "FOREGROUND"] These lines are not working, when new instance starts, cant start apache#CMD service apache2 startRUN echo 'service apache2 start ' > /etc/bash.bashrc Hence I started apache this way , # Set default container command#ENTRYPOINT /bin/bash

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