Docker for Developers - PNWPHP 2016 Workshop

Docker for PHP
Developers
Chris Tankersley
@dragonmantank
Pacific Northwest PHP, September 2016
Pacific Northwest PHP, September 2016 1

What Is Docker?
“Docker is an open platform for developers and sysadmins to build,
ship, and run distributed applications. Consisting of Docker Engine, a
portable, lightweight runtime and packaging tool, and Docker Hub, a
cloud service for sharing applications and automating workflows,
Docker enables apps to be quickly assembled from components and
eliminates the friction between development, QA, and production
environments.”
https://www.docker.com/whatisdocker/

Containers

Normal Bare-Metal Server
CPU RAM HD Network
Operating System
nginx PHP DB

Virtual Machines
CPU RAM HD Network
Operating System
nginx PHP DB
Operating System
nginx PHP DB
Operating System
Hypervisor

Containers
CPU RAM HD Network
Operating System
nginxnginx PHP DB PHP DB

Containers Are Not New
• LXC (Linux Containers)
• OpenVZ
• Systemd-nspawn
• Qemu/kvm
• BSD Jails
• Solaris Zones
• chroot

Docker is an Ecosystem
Docker Engine

Docker is an Ecosystem
Docker ComposeDocker Machine Docker Swarm

How does it work?
Uses a variety of existing
Container technologies
Server Containers
Hyper-V Containers xhyve Virtualization

Sorry OSX < 10.10 and Windows < 10 Users
Docker Toolbox

Let’s use Docker

Running a container
• `docker run` will run a container
• This will not restart an existing container, just create a new one
• docker run [options] IMAGE [command] [arguments]
• [options ]modify the docker process for this container
• IMAGE is the image to use
• [command] is the command to run inside the container
• [arguments] are arguments for the command

Running a simple shell

What’s Going On?
Ubuntu Kernel
/
+ bin/
+ etc/
+ dev/
+ home/
+ usr/
+ var/
+ lib/
+ …
nginx
bash
/
+ bin/
+ etc/
+ dev/
+ home/
+ usr/
+ var/
+ lib/
+ …
php

Running Two Webservers

Some Notes
• All three containers are 100% self contained
• Docker containers share common ancestors, but keep their own files
• `docker run` parameters:
• --rm – Destroy a container once it exits
• -d – Run in the background (daemon mode)
• -i – Run in interactive mode
• --name – Give the container a name
• -p [local port]:[container port] – Forward the local port to the container port

Volumes

Modifying a running container
• `docker exec` can run a command inside of an existing container
• Use Volumes to share data

Persistent Data with Volumes
• You can designate a volume with –v
• Create a named volume with `volume create`
• Volumes can be shared amongst containers
• Volumes can mount data from the host system

Mounting from the host machine

Mounting from the host isn’t perfect
• The container now has a window into your host machine
• Permissions can get screwy if you are modifying in the container
• Most things it creates will be root by default, and you probably aren’t root on
the host machine
• Host-mounted volumes are not portable at all
• OSX and Hyper-V VMs have limited pathings to mount
• OSX has poor I/O performance

Named Data Volumes
• Creates a space that becomes persistent
• Can be mounted anywhere inside your images
• Have our app containers use the data volume to store data
• Use ‘editor containers’ to go in and modify data when needed

Mounting Data Volumes

Why go through the hassle?
• Data volumes are portable, depending on the driver
• Data volumes are safer
• Separates the app containers from data
• Production can use a data volume, dev can use a host volume
• Our app containers stay small
• Works directly with other tools

Network Linking

Docker Links
• Allows containers to ‘see’ each other over the network
• Each container thinks the other one is just another machine
• Containers all have an internal network address, so we don’t need to
expose everything through the host
• Legacy Links work with `--link`
• Can set up virtual networks

More Traditional Setup
INTARWEBS Nginx PHP-FPM
Data Volume
Port 9000
Editor

Let’s Build It

More Notes!
• We can now rebuild sections of the app as needed
• We can restart nginx without impacting PHP
• We can extend much easier
• Docker 1.12 has added a whole bunch of new stuff

BREAK TIME! WOO!

Other Helpful Commands

Inspect a container
docker inspect [options] CONTAINER_NAME
• Returns a JSON string with data about the container
• Can also query
• docker inspect -f “{{ .NetworkSettings.IPAddress }}” web_server
• Really handy for scripting out things like reverse proxies

Work with images
• docker pull IMAGE – Pulls down an image before using
• docker images – Lists all the images that are downloaded
• docker rmi IMAGE – Deletes an image if it’s not being used

Our Goals
• Not change our workflow (much)
• Run PHP 7, Unit Tests, and webserver
• Deploy “easily”

Containerizing Commands

Running Composer
docker run --rm
-v c:/Users/drago/.composer:/root/.composer
-v c:/Users/drago/Projects/workshop:/app
-v c:/Users/drago/.ssh:/root/.ssh
composer/composer
require phpunit/phpunit

Functions!
function docker-composer() {
appname=$(basename `pwd -P`)
appname="${appname/-/}"
imagename='composer/composer'
output=$(docker images | grep "${appname}_composer")
if [ "$?" = "0" ]; then
imagename="${appname}_composer"
fi
docker run --rm -v ~/.composer:/root/.composer -v
$(pwd):/app -v ~/.ssh:/root/.ssh $imagename $*
}

Add our code to the autloader
{
"require": {
"phpunit/phpunit": "^5.5"
},
"autoload": {
"psr-4": {
"DemoApp": "src/"
}
}
}

Run our app
docker run -d --name phptest
-v c:/Users/drago/Projects/workshop/:/app
-w /app/html
-p 8080:80
php:cli
php -S 0.0.0.0:80

Unit Test our Code
docker run --rm -ti
-v c:/Users/drago/Projects/workshop/:/app
-w /app
php:cli
vendor/bin/phpunit -c phpunit.dist.xml

Docker Compose

What is Docker Compose?
• Multi-container orchestration
• A single config file holds all of your container info
• Works with Docker Swarm and a few other tools, like Rancher

Sample docker-compose.yml
version: ‘2’
volumes:
mysqldata:
driver: local
phpserver:
build: ./docker/php
volumes:
- ./:/var/www/
mysqlserver:
image: mysql
environment:
MYSQL_DATABASE: dockerfordevs
MYSQL_ROOT_PASSWORD: docker
volumes:
- mysqldata:/var/lib/mysql
nginx:
build: ./docker/nginx
ports:
- "80:80"
- "443:443"

Creating your own Images

Dockerfile
• Dockerfile is the configuration steps for an image
• Can be created from scratch, or based on another image
• Allows you to add files, create default volumes, ports, etc
• Can be used privately or pushed to Docker Hub

FROM php:7
RUN apt-get update
&& apt-get install –y
libmcrypt-dev
libpng12-dev
libfreetype6-dev
libjpeg62-turbo-dev
&& docker-php-ext-install iconv mcrypt pdo pdo_mysql
COPY build/app /var/www
# …
EXPOSE 80 443
VOLUME /var/www
VOLUME /var/log
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

Build it
docker build -t tag_name ./
• This runs through the Dockerfile and generates the image
• We can now use the tag name to run the image

Add in some Compose

Start the app with Compose

Docker Machine

What is Docker Machine?
• A provisioning tool that is used to set up a box with Docker
• Used in Docker Toolbox to create the VM
• Supports:
• EC2
• Azure
• Digital Ocean
• Hyper-V
• OpenStack
• Virtualbox
• VMWare

Why use it?
• Makes it very easy to spin up new boxes
• Docker Machine handles all of the dirty stuff for you
• Docker Toolbox users are already using it
• Integrates with Docker Swarm
• It is not necessarily portable

Let’s make a machine!

Let’s Connect!

Thank You!
• https://github.com/dragonmantank
• Author of “Docker for Developers”
• https://leanpub.com/dockerfordevs
• http://ctankersley.com
• chris@ctankersley.com
• @dragonmantank

Docker for Developers - PNWPHP 2016 Workshop

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