A Vagrant Primer

https://www.vagrantup.com

What?

• Tool zur Virtualisierung während der Entwicklung
• Ziel: Alle Projektmitarbeiter haben das gleiche Setup
• Ziel: Projektentwicklung isolieren
• Ziel: Möglichst ähnliches Setup zu Produktivserver

Getting started

• Vagrant installieren (https://vagrantup.com)
• VM Provider installieren (z.B. VirtualBox)
• Läuft auf Windows, MacOS und Linux

How?

vagrant init ubuntu/trusty32
vagrant up

Und schon läufts.

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

# All Vagrant configuration is done below. The "2" in Vagrant.configure
# configures the configuration version (we support older styles for
# backwards compatibility). Please don't change it unless you know what
# you're doing.
Vagrant.configure(2) do |config|
  # The most common configuration options are documented and commented below.
  # For a complete reference, please see the online documentation at
  # https://docs.vagrantup.com.

  # Every Vagrant development environment requires a box. You can search for
  # boxes at https://atlas.hashicorp.com/search.
  config.vm.box = "ubuntu/trusty32"

  # Disable automatic box update checking. If you disable this, then
  # boxes will only be checked for updates when the user runs
  # `vagrant box outdated`. This is not recommended.
  # config.vm.box_check_update = false

  # Create a forwarded port mapping which allows access to a specific port
  # within the machine from a port on the host machine. In the example below,
  # accessing "localhost:8080" will access port 80 on the guest machine.
  # config.vm.network "forwarded_port", guest: 80, host: 8080
  config.vm.network "forwarded_port", guest: 8000, host: 8000

  # Create a private network, which allows host-only access to the machine
  # using a specific IP.
  # config.vm.network "private_network", ip: "192.168.33.10"

  # Create a public network, which generally matched to bridged network.
  # Bridged networks make the machine appear as another physical device on
  # your network.
  # config.vm.network "public_network"

  # Share an additional folder to the guest VM. The first argument is
  # the path on the host to the actual folder. The second argument is
  # the path on the guest to mount the folder. And the optional third
  # argument is a set of non-required options.
  # config.vm.synced_folder "../data", "/vagrant_data"

  # Provider-specific configuration so you can fine-tune various
  # backing providers for Vagrant. These expose provider-specific options.
  # Example for VirtualBox:
  #
  # config.vm.provider "virtualbox" do |vb|
  #   # Display the VirtualBox GUI when booting the machine
  #   vb.gui = true
  #
  #   # Customize the amount of memory on the VM:
  #   vb.memory = "1024"
  # end
  #
  # View the documentation for the provider you are using for more
  # information on available options.

  # Define a Vagrant Push strategy for pushing to Atlas. Other push strategies
  # such as FTP and Heroku are also available. See the documentation at
  # https://docs.vagrantup.com/v2/push/atlas.html for more information.
  # config.push.define "atlas" do |push|
  #   push.app = "YOUR_ATLAS_USERNAME/YOUR_APPLICATION_NAME"
  # end

  # Enable provisioning with a shell script. Additional provisioners such as
  # Puppet, Chef, Ansible, Salt, and Docker are also available. Please see the
  # documentation for more information about their specific syntax and use.
  # config.vm.provision "shell", inline: <<-SHELL
  #   sudo apt-get update
  #   sudo apt-get install -y apache2
  # SHELL
  config.vm.provision "shell", path: "vagrant_provision.sh"
end

vagrant_provision.sh

#!/bin/bash

MYSQL_ROOT_PASSWORD=root

debconf-set-selections <<< "mysql-server mysql-server/root_password password $MYSQL_ROOT_PASSWORD"
debconf-set-selections <<< "mysql-server mysql-server/root_password_again password $MYSQL_ROOT_PASSWORD"

apt-get update -q -y
#apt-get upgrade -q -y

apt-get install -q -y python-pip python-virtualenv
apt-get install -q -y mysql-server libmysqlclient-dev python-mysqldb

cat > /home/vagrant/.bash_profile << EOF
source /home/vagrant/venv/bin/activate
cd /vagrant
EOF

mysql -u root -proot <<< "CREATE DATABASE vagrant_demo;"

sudo -u vagrant virtualenv /home/vagrant/venv --system-site-packages
sudo -u vagrant /home/vagrant/venv/bin/pip install -r /vagrant/requirements.txt
sudo -u vagrant /home/vagrant/venv/bin/python /vagrant/djangodemo/manage.py migrate --noinput

How?

• Das lokale Projektverzeichnis erscheint in der VM unter /vagrant
• Einloggen mit vagrant ssh
• Einfaches einrichten von Portforwarding
• Ziel: Server läuft isoliert in der VM
• Ziel: Entwicklung mit gewohnten GUI Tools

Warum?

• Jeder Entwickler arbeitet mit dem gleichen OS, gleiche Datenbank, gleicher Webserver
• Alle verwenden die selben Versionen
• Alle verwenden die selben Versionen wie auf dem Produktivsystem
• Es gibt kein works for me mehr

Use cases

• Neue Entwickler können sofort loslegen
• Deployment testen
• Schnell Wegwerf-VM aufsetzen um etwas auszuprobieren
• Cluster simulieren

Probleme

• Teils langsamer als lokales Setup
• Probleme bei vielen Dateien die über Fileshare gelesen werden
• Evtl. muss man DB Admin-Tooling anpassen

Probleme

• Payoff bei Ein- oder Zwei-Personen Projekten möglicherweise zu hoch
• Vollständige Parität zu Produktivsystem nur schwer erreichbar
• Immer interessantes Werkzeug im Entwicklertoolbelt

Cheers!