Docker for PHP DevelopersChris Tankersley

@dragonmantank

php[world] 2017

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Setup!

WIFI: “php world”, code is `php2017`

Example App:https://github.com/learningcontainers/dockerfordevs

Lunch: Around 12:30pmBreaks: Every so often

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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.”

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https://www.docker.com/whatisdocker/

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What is a Container?

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Normal Bare-Metal Server

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CPU RAM HD Network

Operating System

nginx PHP DB

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Normal Bare-Metal Server

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CPU RAM HD Network

Operating System

nginx PHP DB

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Virtual Machines

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CPU RAM HD Network

Operating System

nginx PHP DB

Operating System

nginx PHP DB

Operating System

Hypervisor

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Containers

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CPU RAM HD Network

Operating System

nginxnginx PHP DB PHP DB

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Containers vs VMs

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Containers Are Not New

• LXC (Linux Containers)• OpenVZ• Systemd-nspawn• BSD Jails• Solaris Zones• chroot

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Containers are just walled processes

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Ubuntu Kernel

/+ bin/+ etc/+ dev/+ home/+ usr/+ var/+ lib/+ …

nginx

bash

/+ bin/+ etc/+ dev/+ home/+ usr/+ var/+ lib/+ …

php

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What is Docker?

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Docker is an Ecosystem

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Docker Engine

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Docker is an Ecosystem

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Docker ComposeDocker Machine Docker Swarm

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How does it work?

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Uses a variety of existingContainer technologies

Server ContainersHyper-V Containers xhyve Virtualization

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Sorry OSX < 10.10 and Windows < 10 Users

Docker Toolbox

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Let’s use Docker

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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

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Running a simple shell

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Running a simple shell

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Running a simple shell

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What’s Going On?

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Ubuntu Kernel

/+ bin/+ etc/+ dev/+ home/+ usr/+ var/+ lib/+ …

nginx

bash

/+ bin/+ etc/+ dev/+ home/+ usr/+ var/+ lib/+ …

php

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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Running Two Webservers

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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

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Volumes

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Modifying a running container

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

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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

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Mounting from the host machine

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Mounting from the host machine

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Mounting from the host machine

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Mounting from the host machine

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Mounting from the host machine

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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

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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

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vim Tutorial

• vim is a Modal text editor• ESC will drop you back to default mode• :new /opt/webconfig/default to create a new file• In default mode, i will get us into interactive (edit) mode• :w to save a file• :q will quit

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Mounting Data Volumes

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Mounting Data Volumes

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Mounting Data Volumes

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Mounting Data Volumes

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Mounting Data Volumes

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Mounting Data Volumes

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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

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Networking

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Networking

• Docker can create multiple network “pools”• Each container gets an IP address• Containers can be attached to multiple networks• Docker network allow service discovery inside networks

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Legacy - Docker Links

• Legacy Links work with `--link`• Only works on the legacy “bridge” network• Doesn’t support service discovery

• Not worth it to use anymore

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Docker Networks

• Discreet IP pool for containers• Containers can be added and removed to the network at whim• Service discovery though ‘--network-alias’• Can be set up to work across hosts

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Create a network

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Attach to a network

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Ping the web container

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Add another web and kill web1

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BREAK TIME! WOO!

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Other Helpful Commands

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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

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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

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Containerizing An Application

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Our Goals

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

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Just try and run it

docker run -d --name d4dapp \

-v C:\drago\Projects\dockerfordevs-app:/var/www/ \

-p 8080:80

php:apache

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Checking Logs

• Containers log to stdout/stderr• Docker aggregates the logs• Can be viewed with docker logs

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Oops

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Custom Images

• PHP images are pretty bare• Lots of times need to install extensions

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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

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docker/Dockerfile

FROM php:apache

RUN a2enmod rewrite

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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

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Build it

docker build -t d4dapp docker/

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Use the new image

docker run -d --name d4dapp \

-v C:\drago\Projects\dockerfordevs-app:/var/www/ \

-p 8080:80

d4dapp

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Use the new image

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Slightly better

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Install Dependencies

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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 \

install

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Better!

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Look at queues!

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docker/Dockerfile

FROM php:apache

RUN a2enmod rewrite\

&& docker-php-ext-install pdo_mysql

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Rebuild the image

docker build -t d4dapp docker/

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Rebuild the container

$ docker rm -f d4dapp

$ docker run -d --name d4dapp \

-v C:\drago\Projects\dockerfordevs-app:/var/www/ \

-p 8080:80

d4dapp

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Progress!

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Docker Compose

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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

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Sample docker-compose.ymlversion: '2'

volumes: mysqldata: driver: local

services: d4dapp: build: ./docker/ volumes: - ./:/var/www/ ports: - 8080:80

mysqlserver: image: mysql environment: MYSQL_DATABASE: dockerfordevs MYSQL_ROOT_PASSWORD: 's3curep@assword' volumes: - mysqldata:/var/lib/mysql

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No longer use docker run

$ docker rm –f d4dapp

$ docker-compose up -d

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Now we have 2 containers

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Config for DB now points to the service name

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<?php

return [ 'debug' => true,

'config_cache_enabled' => false,

'db' => [ 'driver' => 'Pdo_Mysql', 'hostname' => 'mysqlserver', 'port' => '3306', 'database' => 'dockerfordevs', 'user' => 'root', 'password' => 's3curep@assword', ],];

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Yay!

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Install our DB Migration Software

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 robmorgan/phinx

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Set up phinx

docker run --rm \

-v C:\Users\drago\Projects\dockerfordevs-app\:/app \

-w /app \

php:cli php vendor/bin/phinx init

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Run the migration

docker run --rm \

-v C:\Users\drago\Projects\dockerfordevs-app\:/app \

-w /app \

--network dockerfordevsapp_default \

php:cli php vendor/bin/phinx migrate

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Oops

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Let’s use the existing container

docker-compose run --rm \

-v C:\Users\drago\Projects\dockerfordevs-app\:/app \

-w /app \

d4dapp php vendor/bin/phinx migrate

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Good…

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It Lives!

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Unit Testing

docker run --rm \

-v C:\Users\drago\Projects\dockerfordevs-app\:/app \

-w /app \

d4dapp php vendor/bin/phpunit -c .

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Running the tests

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Build a service

service:

testrunner:

build: ./docker/

volumes:

- ./:/app

working_dir: /app

command: vendor/bin/phpunit -c .

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Run the tests with the service

docker-compose run --rm testrunner

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Running the tests

Docker Machine

ZendCon, October 2016 104

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

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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

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Let’s make a machine!

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Let’s Connect!

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BREAK TIME AGAIN! WOO!

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Production Considerations

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12 Factor Applications

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1. Codebase

One codebase tracked in revision control, many deploys

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Repo Tips

• Keep everything in your repository• Tag releases• Never move tags

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2. Dependencies

Explicitly declare and isolate dependencies

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Dependencies

• Commit both composer.json and composer.lock files• Commit Dockerfiles to the same repo as the codebase

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3. Config

Store config in the environment

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Configuration

• Anything that is environment specific should move to environment vars• Makes it much easier to build and deploy code• Code cares less what external services it is talking to

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Use Environment Vars

• Can specify them one-by-one– docker run ­e VAR_NAME=value

• Can specify a file– docker run ­­env­file=filename

• Can specify in docker-compose.yml

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4. Backing Services

Treat backing services as attached resources

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Everything is “external”

• Never talk to local sockets• Don’t make a determination between “locally” hosted and third party• Easier to switch environments• Easier to scale up

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5. Build, release, run

Strictly separate build and run stages

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The Workflow

• Build step installs dependencies, compiles files, and generates a Build Artifact that can be deployed

– Does not contain any deployment configuration

• Release step pushes a Build Artifact into an environment– Runs DB migrations, anything needed to happen before running

• Run step runs the app fully in the environment

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Tips

• Build Artifact can be an image• Builds should be completely reproducible• Release always take a build artifact, never directly from the repo• Tag all your builds• Track all your releases

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Build Step - Start Small

• Build your application• Run composer• Run npm/bower• Build JS/CSS

• Use the compiled output to build an image with docker build• Push full image to private registry

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docker build

• Additional options to look at• -f, --file – Specify a different filename for the Dockerfile• --no-cache – Don’t use a cached layer• --pull – Always pull a new version of the image

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Sample usage

docker build \

--no-cache \

–f docker/php/phpserver.dockerfile \

–t prod_php /opt/builds/20161010

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phpserver.dockerfile

FROM php:fpm

RUN docker-php-ext-install pdo pdo_mysql

COPY ./ /var/www

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6. Processes

Execute the app as one or more stateless processes

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Built Into Docker

• One Process per container• Allows tools to scale just what needs to be scaled• Allows images to be swapped out as needed

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7. Port Binding

Export services via port binding

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Built Into Docker (Again)

• Each container gets its own IP and exposes its own ports• Processes should already be talking over a network• Can work with service locators that are port-based

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8. Concurrency

Scale out via the process model

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How well does your app handle scaling?

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Built Into Docker (Again) (Again)

• One Process per container• Scale up just the container that is needed• App should not care how many instances of each service are running

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9. Disposability

Maximize robustness with fast startup and graceful shutdown

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Signals

• Docker starts containers fairly quickly• Applications should gracefully shut down, not just die• Docker sends a SIGTERM when shutting down a container• Your CLI apps may need to handle SIGTERM properly

– Cal Evans, “Signalling PHP”

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10. Dev/prod Parity

Keep development, staging, and production as similar as possible

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11. Logs

Treat logs as event streams

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Logging in Docker

• Various logging options built in– JSON file (default)– Fluentd– Syslog– Journald– Gelf– Splunk– Aws– Etwlogs– Gcplogs

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Push logs remotely

• When possible, push Docker logs to a remote service– Container logs only exist while the container exists

• Allows logs to be viewed in a single place• No need to get into actual servers• Can host yourself, or pay for a SaaS• ELK stack is very popular

– Docker uses fluentd instead

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Setting up fluentdservices:

  d4dapp:

    build: ./docker/d4dapp

    depends_on:

      ­ fluentd

    volumes:

      ­ ./:/var/www/

    ports:

      ­ 8080:80

    logging:

      driver: "fluentd"

      options:

        fluentd­address: 127.0.0.1:24224

        tag: apache.access

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Setting up fluentdservices:

  fluentd:

    build: docker/fluentd

    depends_on:

      ­ elasticsearch

    volumes:

      ­ ./docker/fluentd/fluent.conf:/fluentd/etc/fluent.conf

    ports:

      ­ 24224:24224

      ­ 24224:24224/udp

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Setting up fluentdFROM fluent/fluentd

RUN ["gem", "install", "fluent­plugin­elasticsearch", "­­no­rdoc", "­­no­ri", "­­version", "1.9.2"]

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Setting up fluentd[See Config File in repo]

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Setting up ElasticSearch and Kibanaservices:

  elasticsearch:

    image: elasticsearch

    expose:

      ­ 9200

    ports:

      ­ 9200:9200

  kibana:

    image: kibana

    depends_on:

      ­ elasticsearch

    ports:

      ­ 5601:5601

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Viewing Logs

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Logging notes

• docker logs does not work with external logging, only JSON• This example can be cleaned up a bit• Kibana syntax can be a bit odd to work with

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12. Admin Processes

Run admin/management tasks as one-off processes

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BREAK TIME AGAIN! WOO!

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Deployment using Docker Compose

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Very Good for Small Deployments

• Can be used to augment your dev environment• Works well with Docker Machine

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Create a machine

docker-machine create --driver digitalocean \

--digital-ocean-access-token [token] \

phpworld2017

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SunshinePHP 2017 153

Switch to the remote node

• Run docker-machine env phpworld2017

& "C:\Program Files\Docker\Docker\Resources\bin\docker-machine.exe" env phpworld2017 | Invoke-Expression

eval $(docker-machine env phpworld2017)

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Set up docker-compose

• Docker Compose allows multiple config files with -f• Have a base docker-compose.yml for Production• Add a secondary one for Development

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version: '2'

volumes:

mysqldata:

driver: local

services:

nginx:

build:

context: ./

dockerfile: ./nginx.dockerfile

ports:

- 80:80

- 443:443

phpserver:

build:

context: ./

dockerfile: ./phpserver.dockerfile

working_dir: /var/www/public

mysqlserver:

image: mysql

environment:

[redacted]

volumes:

- mysqldata:/var/lib/mysql

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docker-compose.yml

version: '2'

volumes:

mysqldata:

driver: local

services:

nginx:

image: nginx

volumes:

- ./output_dev:/var/www/public:ro

- ./app/nginx/default.conf:/etc/nginx/conf.d/default.conf

- ./ssl:/etc/nginx/ssl/

phpserver:

build:

context: ./

dockerfile: ./phpserver.dockerfile

working_dir: /var/www/public

volumes:

- ./app:/var/www/

- ./vendor:/var/www/vendor

mysqlserver:

image: mysql

environment:

[redacted]

volumes:

- mysqldata:/var/lib/mysql

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docker-compose.dev.yml

When doing development

docker-compose \

–f docker-compose.yml \

–f docker-compose.dev.yml \

up -d

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When doing a deployment

docker-compose up -d

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Other Alternative – Variable Substitution

• Docker Compose allows variable substitution inside the file• Wrap variables in ${}• image: ${DEPLOY_VERSION}_php

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When doing a deployment

docker-compose up -d

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Docker Swarm

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What is Swarm?

• Docker-supplied clustering• Define a series of services that can be deployed

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Setup

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Manager

Node 2Node 1

Register a node as a Manager

docker swarm init ----advertise--addr 172.16.0.245

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Add nodes

docker swarm join --token [token] 172.16.0.245:2377

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docker-compose.yml

version: '3'

services:

phpserver:

image: php:apache

ports:

- 80:80

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Deploy the stack

$ docker stack deploy -c docker-compose.yml myapp

Creating network myapp_default

Creating service myapp_phpserver

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docker-compose.yml

version: '3'

services:

phpserver:

image: php:apache

ports:

- 80:80

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Deploy the stack

$ docker stack deploy -c docker-compose.yml myapp

Creating network myapp_default

Creating service myapp_phpserver

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docker-compose.yml

version: '3'

services:

phpserver:

image: php:apache

ports:

- 80:80

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docker-compose.yml

version: '3'

services:

phpserver:

image: php:apache

ports:

- 80:80

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docker stack ps myappID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS

72mud5othsjf myapp_phpserver.1 nginx:latest node2 Running Running 8 minutes ago

wsf3m32u9vcr \_ myapp_phpserver.1 php:apache manager1 Shutdown Shutdown 11 minutes ago

xf3wyh289bec myapp_phpserver.2 nginx:latest node1 Running Preparing 20 seconds ago

fehf1vdx4m0r myapp_phpserver.3 nginx:latest manager1 Running Preparing 20 seconds ago

pwnq65e6w7ew myapp_phpserver.4 nginx:latest manager1 Running Preparing 20 seconds ago

roxtanjughq8 myapp_phpserver.5 nginx:latest node2 Running Running 20 seconds ago

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Thank You!

• Software Engineer for InQuest

• Author of “Docker for Developers”• https://leanpub.com/dockerfordevs

• Co-Host of “Jerks Talk Games”• http://jerkstalkgames.com

• http://ctankersley.com

• chris@ctankersley.com

• @dragonmantank

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