Containerizing PHP Applications (PHP World 2016)

Docker is hot right now and if you’re ready to get started, you’ve come to the right place. In this tutorial, we’ll go over basic Docker concepts like Dockerfiles, containers and images. We’ll look at some sample applications including WordPress, Drupal as well as some framework-based examples. We will talk about strategies for building Docker images for these scenarios, and we’ll also cover how to handle external dependencies such as storage, databases, caches in both development and production.

Transcript

1. Containerizing PHP Applications
   Josh Butts
   PHP World 2016
   

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2. About Me
   • VP of Engineering

   at Offers.com
   • Austin PHP Organizer
   • github.com/jimbojsb
   • @jimbojsb
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4. About Offers.com
   • We help people save money
   • Launched in 2009
   • 200k lines of PHP across
   several apps
   • Billions of requests / month
   • Runs entirely in Docker
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5. Agenda In No Particular Order
   • What is Docker
   • Docker Terminology
   • Running Docker in Dev vs Prod
   • Docker CLI tools
   • Anatomy of a Dockerfile
   • Building a Dockerfile for PHP apps
   • Wordpress Example
   • Laravel Example
   • Docker orchestration
   • Docker Compose
   • Registries & Sharing Containers
   

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6. SURVEY
   Quick
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7. CAVEATS
   A Few
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8. DOCKER?
   What is
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9. BUILDING, RUNNING AND
   DISTRIBUTING APPLICATION
   CONTAINERS
   Docker is a tool for
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10. What is Docker?
    • Docker allows you to package
    applications with infrastructure
    • Docker uses Linux kernel container
    technology
    • Docker is well suited for distributed
    and highly available applications
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11. High Level Overview
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12. Who Cares?
    • Docker allows engineers to
    choose exactly the stack for any
    app
    • Containers run anywhere that
    runs Docker
    • Ops focuses on infrastructure
    instead of stacks
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13. Docker Dictionary - Container
    • Container
    • A running instance of your app
    and it’s complete software
    stack
    • You might have many identical
    containers running
    • Often runs just one process
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14. Docker Dictionary - Image
    • An image is the compiled
    distributable version of your app
    and it’s stack
    • Images are built from
    Dockerfiles
    • You can start many containers
    from the same image
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15. Docker Dictionary - Layer
    • Docker uses a layering system
    to optimize storage
    • Each line in your Dockerfile is a
    layer
    • Many layers make up an image
    • Images share common layers
    where possible
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16. Docker Dictionary - Dockerfile
    • The Dockerfile is a text file that
    lives in your project root
    • Describes how to build your image
    • Installs software packages,
    configures runtimes, etc
    • Tells Docker what command to
    run and what ports to open
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17. Docker Dictionary - Registry
    • A server that stores images
    • Provides organization and
    authentication as needed
    • Facilitates sharing of pre-built
    images
    • Example: DockerHub, Amazon
    ECR
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18. The Docker Binary
    • Both the CLI client and the
    server
    • Written in Go
    • Speaks REST-ish over Unix
    socket or TCP/SSL
    • CLI and server can be on
    different hosts
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19. Building Images
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    Dockerfile Image
    Container
    Registry
    Image
    Image
    Build
    Push/Pull
    Run
    

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20. How Containers Run
    • Docker daemon runs as root and
    starts containers
    • Containers are basically stateless
    • Can expose local storage if you
    need to
    • Can’t see each other’s files
    • State is gone on exit
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21. Outsource your Persistence
    • Cloud (AWS) example:
    • RDS for database storage
    • Sessions in Memcached or Redis
    • File storage in S3
    • This may require changes to your
    app!
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22. Docker vs Virtualization
    • Docker is lightweight
    • No overhead of a guest OS
    • Docker can be controlled /
    contained by systemd and
    cgroups
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23. DOCKER
    What does it mean to run
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24. Running the Docker Daemon
    • Unless you’re running Linux,
    you need a VM (i.e. dev
    environment)
    • For MacOS / Windows, Docker
    provides a VM tool
    • docker -d
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25. A Word on the Control OS
    • Any modern Linux should be
    able to run Docker
    • I personally don’t recommend
    Ubuntu
    • CoreOS is a small Linux distro
    that is designed to run Docker in
    production
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26. Typical Non-Linux Setup
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    MacOS
    Projects /
    Source Code VM
    Linux
    Docker
    Daemon
    Containers
    Containers
    Containers
    Containers
    Docker
    CLI
    

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27. HELLO WORLD
    EXAMPLE
    Lets try a
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28. Naming Images
    • hello-world
    • hello-world:latest
    • _/hello-world
    • dockerhub.com/_/hello-world
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29. Naming Containers
    • Containers get a name
    • It’s different from the name of
    the image
    • It’s dumb by default
    • use --name
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30. Dockerfiles
    • FROM - specify your base image
    • RUN - run commands in the
    context
    • ADD - put your files in
    • EXPOSE - listen on ports
    • ENV - set environment vars
    • VOLUME - persistent storage
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31. DOCKERFILE
    Lets actually write a
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32. Building Images from Dockerfiles
    • docker build .
    • use -t to give it a repo / tag
    • docker images to see what’s
    available on your system
    • docker rmi to delete images
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33. Running Containers
    • docker run --name [image]
    • At runtime you can
    • add volumes
    • specify port mappings
    • change the CMD
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34. PHP APPLICATIONS
    Building Dockerfiles for
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35. My Container Philosophy
    • ONE Dockerfile for your app
    • Use that docker file for dev and
    prod
    • Default to prod, configure for
    dev
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36. Docker Compose
    • Docker Compose lets you
    orchestrate containers
    • Doesn’t do anything that Docker
    itself can’t do
    • YAML config file
    • Speaks the Docker Remote API
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37. WORDPRESS
    Lets build a Dockerfile for
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38. LARAVEL
    Lets build a Dockerfile for
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39. Github Links
    • http://github.com/jimbojsb/wp-docker-
    demo
    • http://github.com/jimbojsb/phpcli-
    docker-demo
    • http://github.com/jimbojsb/phpweb-
    docker-demo
    • http://github.com/jimbojsb/laravel-
    docker-demo
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40. JOIND.IN/TALK/9D3FC
    I’d love your feedback:
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