Docker for Developers

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Thanks to tools like vagrant, puppet/chef, and Platform as a Service services like Heroku, developers are extremely used to being able to spin up a development environment that is the same every time. What if we could go a step further and make sure our development environment is not only using the same software, but 100% configured and set up like production. Docker will let us do that, and so much more. We'll look at what Docker is, why you should look into using it, and all of the features that developers can take advantage of.

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Docker for Developers

  1. 1. Docker for Developers Chris Tankersley @dragonmantank Lonestar PHP 2016 Lonestar PHP 2016 1
  2. 2. Who Am I •  PHP Programmer for over 11 years •  Sysadmin/DevOps for around 9 years •  Using Linux for more than 15 years •  hGps://github.com/dragonmantank •  Author of “Docker for Developers” •  Reigning, Defending, Undisputed PHP MTG Champion of the World Lonestar PHP 2016 2
  3. 3. Docker Lonestar PHP 2016 3
  4. 4. What Is Docker? “Docker is an open plaUorm for developers and sysadmins to build, ship, and run distributed applicaVons. ConsisVng of Docker Engine, a portable, lightweight runVme and packaging tool, and Docker Hub, a cloud service for sharing applicaVons and automaVng workflows, Docker enables apps to be quickly assembled from components and eliminates the fricVon between development, QA, and producVon environments.” Lonestar PHP 2016 4 hGps://www.docker.com/whaVsdocker/
  5. 5. What is it from a technical standpoint? •  Docker is a wrapper around Containers •  Docker Engine is the packaging porVon that builds and runs the containers •  Docker Hub allows you to publish images for others to use •  Docker Machine is a bare-metal provisioning tool •  Docker Swarm is an load-balancing deployment tool •  Docker Compose is a mulV-container build system Lonestar PHP 2016 5
  6. 6. Containers Lonestar PHP 2016 6
  7. 7. Normal Bare-Metal Server Lonestar PHP 2016 7 CPU RAM HD Network OperaVng System nginx PHP DB
  8. 8. Virtual Machines Lonestar PHP 2016 8 CPU RAM HD Network OperaVng System nginx PHP DB OperaVng System nginx PHP DB OperaVng System Hypervisor
  9. 9. Containers Lonestar PHP 2016 9 CPU RAM HD Network OperaVng System nginx nginx PHP DB PHP DB
  10. 10. Docker can use many different containers •  Since 0.9.0 it supports: •  LXC (Linux Containers) – Started with LXC when it was released •  OpenVZ •  Systemd-nspawn •  libvert-sandbox •  Qemu/kvm •  BSD Jails •  Solaris Zones •  chroot Lonestar PHP 2016 10
  11. 11. Runs on *nix and Windows Hyper-V •  No naVve container drivers for OSX* •  Amazon has ElasVc Container Service, and Microsok Azure has Azure Container Service Lonestar PHP 2016 11
  12. 12. Sorry OSX Users •  Docker support is officially maintained through Docker Toolbox Lonestar PHP 2016 12
  13. 13. Docker Toolbox also is for Windows Lonestar PHP 2016 13
  14. 14. Let’s use Docker Lonestar PHP 2016 14
  15. 15. Running a container •  `docker run` will run a container •  This will not restart an exisVng container, just create a new one •  docker run [opVons] IMAGE [command] [arguments] •  [opVons ]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 Lonestar PHP 2016 15
  16. 16. Running a simple shell Lonestar PHP 2016 16
  17. 17. Running Two Webservers Lonestar PHP 2016 17
  18. 18. 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 interacVve mode •  --name – Give the container a name •  -p [local port]:[container port] – Forward the local port to the container port Lonestar PHP 2016 18
  19. 19. Volumes Lonestar PHP 2016 19
  20. 20. Modifying a running container •  `docker exec` can run a command inside of an exisVng container •  Use Volumes to share data Lonestar PHP 2016 20
  21. 21. Persistent Data with Volumes •  You can designate a volume with -v •  Volumes can be shared amongst containers •  Volumes can mount data from the host system Lonestar PHP 2016 21
  22. 22. Mounting from the host machine Lonestar PHP 2016 22
  23. 23. 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 •  Docker Toolbox’s VM only allows mounVng from within your home directory Lonestar PHP 2016 23
  24. 24. Container Data Volumes •  Uses a small container that does nothing but stores data •  Have our app containers use the data volume to store data •  Use ‘editor containers’ to go in and modify data when needed Lonestar PHP 2016 24
  25. 25. Mounting Data Volumes Lonestar PHP 2016 25
  26. 26. Why not run SSH inside of the container? •  Well, you can… •  Docker is designed for one command per container •  If you need to modify data, then you need to change your setup •  If you have to run SSH, then you need a way to run SSH and your command Lonestar PHP 2016 26
  27. 27. Why go through the hassle? •  Data volumes are portable •  Data volumes are safer •  Separates the app containers from data •  ProducVon can use a data volume, dev can use a host volume •  Our app containers stay small Lonestar PHP 2016 27
  28. 28. Network Linking Lonestar PHP 2016 28
  29. 29. 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 •  Currently only works if all the containers are on one machine, Docker 1.10 should fix that Lonestar PHP 2016 29
  30. 30. More Traditional Setup Lonestar PHP 2016 30 INTARWEBS Nginx PHP-FPM Data Volume Port 9000 Editor
  31. 31. Let’s Build It Lonestar PHP 2016 31
  32. 32. More Notes! •  We can now rebuild secVons of the app as needed •  We can restart nginx without impacVng PHP •  We can extend much easier •  Linked containers will not update if they are stopped/started •  If we upgrade PHP, we have to destroy/create the web_server container again Lonestar PHP 2016 32
  33. 33. Creating your own Images Lonestar PHP 2016 33
  34. 34. Dockerfile •  Dockerfile is the configuraVon 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 Lonestar PHP 2016 34
  35. 35. FROM phusion/baseimage:0.9.10 # … CMD ["/sbin/my_init"] # Nginx-PHP Installation RUN apt-get update RUN apt-get install -y vim git curl wget build-essential python-software-properties php5-cli php5-fpm php5-mysql php5-pgsql php5-sqlite php5-curl php5-gd php5-mcrypt php5-intl php5-imap php5-tidy mysql-client # … RUN mkdir /var/www ADD build/default /etc/nginx/sites-available/default # … EXPOSE 80 22 VOLUME /var/www VOLUME /etc/nginx VOLUME /etc/php/ VOLUME /var/log RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* Lonestar PHP 2016 35
  36. 36. 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 Lonestar PHP 2016 36
  37. 37. Other Helpful Commands Lonestar PHP 2016 37
  38. 38. Inspect a container docker inspect [opVons] CONTAINER_NAME •  Returns a JSON string with data about the container •  Can also query •  docker inspect -f “{{ .NetworkSe{ngs.IPAddres }}” web_server •  Really handy for scripVng out things like reverse proxies Lonestar PHP 2016 38
  39. 39. 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 Lonestar PHP 2016 39
  40. 40. Docker Machine Lonestar PHP 2016 40
  41. 41. 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 Lonestar PHP 2016 41
  42. 42. Creating a new machine Lonestar PHP 2016 42
  43. 43. 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 Lonestar PHP 2016 43
  44. 44. Docker Swarm Lonestar PHP 2016 44
  45. 45. What is Docker Swarm? •  Cluster management tool developed by Docker •  Looks like a machine running docker, but is actually many machines Lonestar PHP 2016 45
  46. 46. Create a Swarm token $ docker run --rm swarm create 2 //... 340122bb69c98825b4ac7094c87a07e21 Lonestar PHP 2016 46
  47. 47. Create a Swarm Master $ docker-machine create -d virtualbox --swarm --swarm-master --swarm-discovery token://40122bb69c98825b4ac7094c87a07e21 swarm-master Lonestar PHP 2016 47
  48. 48. Add nodes to the swarm docker-machine create -d virtualbox --swarm --swarm-discovery token://40122bb69c98825b4ac7094c87a07e21 swarm-node-1 docker-machine create -d virtualbox --swarm --swarm-discovery token://40122bb69c98825b4ac7094c87a07e21 swarm-node-2 Lonestar PHP 2016 48
  49. 49. Switch to the master eval $(docker-machine env --swarm swarm-master) Lonestar PHP 2016 49
  50. 50. Add some containers Lonestar PHP 2016 50
  51. 51. Docker Compose Lonestar PHP 2016 51
  52. 52. What is Docker Compose? •  MulV-container orchestraVon •  A single config file holds all of your container info •  Works with Docker Swarm and a few other tools, like Rancher Lonestar PHP 2016 52
  53. 53. Sample docker-compose.yml phpserver: build: ./docker/php volumes: - /home/ctankersley/Projects/dockerfordevs:/var/www/ links: - mysqlserver mysqlserver: image: mysql environment: MYSQL_DATABASE: dockerfordevs MYSQL_ROOT_PASSWORD: docker volumes: - /var/lib/mysql nginx: build: ./docker/nginx ports: - "80:80" - "443:443" links: - phpserver Lonestar PHP 2016 53
  54. 54. Docker Compose in Action Lonestar PHP 2016 54
  55. 55. Let’s build an application Lonestar PHP 2016 55
  56. 56. The Goal •  A three container applicaVon with nginx, php, and mysql •  ApplicaVon will read and write to the database •  Can deploy to a producVon machine Lonestar PHP 2016 56
  57. 57. Folder Structure Lonestar PHP 2016 57
  58. 58. A basic docker-compose.yml phpserver: image: php:7-fpm volumes: - ./application:/var/www/ nginx: image: nginx ports: - "80:80" - "443:443" volumes: - ./nginx:/etc/nginx/conf.d/ links: - phpserver Lonestar PHP 2016 58
  59. 59. nginx/nginx.conf server { listen 80; root /var/www/html; index index.html index.htm index.php; access_log /dev/stdout; error_log /dev/stderr; location / { try_files $uri $uri/ /index.html /index.php?$query_string; } location ~ .php$ { fastcgi_split_path_info ^(.+.php)(/.+)$; fastcgi_pass phpserver:9000; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } Lonestar PHP 2016 59
  60. 60. Hello World <?php echo "Hello World"; Lonestar PHP 2016 60
  61. 61. Bringing it to life Lonestar PHP 2016 61
  62. 62. Adding in MySQL phpserver: image: php:7-fpm volumes: - ./application:/var/www/ links: - mysqlserver mysqlserver: image: mysql environment: MYSQL_DATABASE: dockerfordevs MYSQL_ROOT_PASSWORD: docker volumes: - /var/lib/mysql Lonestar PHP 2016 62
  63. 63. Docker Compose changes aren’t automatic •  You will need to stop, then bring the system again •  docker-compose stop •  docker-compose up •  Docker Compose will generally only restart boxes that have config changes •  Docker Compose will not automaVcally fix links Lonestar PHP 2016 63
  64. 64. Connecting to the database <?php $hostname = 'mysqlserver'; $database = 'dockerfordevs'; $user = 'root'; $password = 'docker'; $dbh = new PDO('mysql:host=' . $hostname . ';dbname=' . $database . '', $user, $password); echo 'Hello World'; Lonestar PHP 2016 64
  65. 65. Testing it Lonestar PHP 2016 65
  66. 66. Why didn’t it work? •  Default PHP images ship with barely any extensions enabled by default •  We will need a custom PHP Image Lonestar PHP 2016 66
  67. 67. Update our docker-compose.yml phpserver: build: ./docker/php volumes: - ./application:/var/www/ links: - mysqlserver Lonestar PHP 2016 67
  68. 68. Custom Docker File FROM php:7-fpm # Install modules RUN apt-get update && apt-get install -y libmcrypt-dev && docker-php-ext-install pdo && docker-php-ext-install pdo_mysql CMD ["php-fpm"] Lonestar PHP 2016 68
  69. 69. Let’s try that again Lonestar PHP 2016 69
  70. 70. Deploying Lonestar PHP 2016 70
  71. 71. I can’t answer this for you Lonestar PHP 2016 71 ¯_(ツ)_/¯
  72. 72. Questions? Lonestar PHP 2016 72
  73. 73. Each situation is different •  You will probably build something custom, using exisVng tools •  Do you use data volumes? •  Do you just package the enVre compiled app? •  Does it need to be distributed? •  Is it going on Swarm, or Amazon ECS? Lonestar PHP 2016 73
  74. 74. Things to consider •  Docker Compose will only deploy an app to one server •  Docker Swarm is preGy low-level and bare-bones •  Volumes on Swarm cannot be shared across hosts •  Host mounVng is 99.99999% of the Vme not what you want to do Lonestar PHP 2016 74
  75. 75. Rancher is a good start •  Provides a nice GUI to manage everything •  Allows volume sharing and networking across hosts •  Works with docker-compose.yml files •  These files can be supplemented with environment variables Lonestar PHP 2016 75
  76. 76. Rancher in action Lonestar PHP 2016 76
  77. 77. Questions? Lonestar PHP 2016 77
  78. 78. http://ctankersley.com chris@ctankersley.com @dragonmantank https://joind.in/talk/2d8b6 Lonestar PHP 2016 78

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