Managing virtual machines with Vagrant

Vagrant is a command line tool that provides you with a configurable,reproducible and portable development environment using  VMs .It lets you define and use preconfigured disk images to create new VMs from.

  Also you can configure vagrant to use provisioners such as shell scripts,puppets or chef to bring your VM to desired state.

Note:

Chef comes with Test kitchen ,Which enables you to test your cookbooks on Vagrant with out you needing  to setup anything manually.

You only need to follow this section, if you want to learn how to use Vagrant  and chef for advanced cases.

we will see how to use vagrant to manage VMs using virtual box  and chef client as a provisioner.

Steps:

1)  Download and install  VirtualBox at https://www.virtualbox.org/wiki/Downloads
2)  Download  and install Vagrant  at https://www.vagrantup.com/downloads.html
3)  Install the omnibus vagrant plugin to enable  Vagrant   to install the chef client on your VM by running the following command:

local@workstation:~/chef-repo $ vagrant plugin install  vagrant-plugin
Installed the plugin 'vagrant-omnibus' (1.5.0)'!

How to do it?

Create and boot a virtual node by using vagrant:

1) Visit https://github.com/chef/bento and choose a vagrant  box to base  your VMs  on,We will use the amd64 image of ubuntu -16.04 in this example.

2) The URL of that  box  is http://opscode-vm-bento.s3.amazonaws.com/vagrant/virtualbox/opscode_ubuntu-16.04_chef-provisionerless.box

3) Create a new Vagrantfile . Make sure that you replace  <YOUR-ORG>  with the name of your organization on the chef server.Use the name and URL  of the box  file you noted down in the first step as config.vm.box  and config.vm.box_url :

local@workstation:~/chef-repo $ vi Vagrantfile

Vagrant.configure("2") do |config|
 config.vm.box= "opscode-ubuntu-16.04"
 config.vm.box_url          =  "https://github.com/chef/bento and choose a vagrant  box to base  your VMs  on,We will use the amd64 image of ubuntu -16.04"
 config.omnibus.chef_version = :latest
config.vm.provision :chef_client  do |chef|
chef.provisioning_path = "/etc/chef"
chef.chef_server_url =  "https://api.chef.io/orgnsations/<YOUR_ORG>
chef.validation_key_path  = ".chef/<YOUR_USER>.pem"
chef.validation_client_name =  "<YOUR_USER>"
chef.node_name = "server"
end
end

Create your virtual node using Vagrant:

local@workstation:~/chef-repo $ vagrant up


Bringing machine  'default' up  with 'virtualbox'  provider


Login to your virtual node using SSH:


local@workstation:~/chef-repo $ vagrant ssh 

vagrant@ssh:~ $ 

Validate that the chef server knows your virtual machine as a client called server.


local@workstation:~/chef-repo $  knife client list

osr-validator


Go to  https://manage.chef.io/organsations/<YOUR ORGANSATION>/nodes and validate  that your new virtual machine shows up a registered node.


How it works?


The   Vagrantfile is written in  a Ruby Domain specific Language (DSL)  to configure the vagrant virtual machines . We want to boot  a simple Ubuntu VM . Lets go through  the Vagrantfile step by step

First,we create a config object . Vagrant will use this config object  to configure  the VM:

Vagrant.configure("2") do |config|
.....
end


   
Inside the config block , we tell  Vagrant which  VM image  to use,  in order to  boot the node:

config.vm.box  =  "opscode-ubuntu-16.04"
config.vm.box_url           =        "http://opscode-vm-bento.s3.amazonaws.com/vagrant/virtualbox/opscode_ubuntu-16.04_chef-provisionless.box"


We want to boot  our VM using  a so called  Bento Box, we provided by chef . We ubuntu Version 16.04 here.

As we want  our  VM to have the chef client installed, we tell the omnibus  vagrant plugin to use the latest version of chef client:


config.omnibus.chef_version= :latest


After selecting the VM image to boot, we configure  how to provision the box by using chef.

The chef configuration happens in a nested ruby block:


config.vm.provision :chef_client do |chef|
.....
end


Inside the chef block ,we need to instruct  Vagrant  on how to hook up our virtual node to the Chef server.First,we need to tell vagrant  where to store all  the Chef stuff  on your node.

chef.provisioning_path  = "/etc/chef"


Vagrants need to understand the API endpoint of your chef server .If you use hosted chef, it is https://api.chef.io/organizations/<YOUR_ORG> .You need  to replace <YOUR_ORG>  with the name of the organization that you created in your account on hosted chef.

If your using your own chef server, change the URL accordingly,

chef.chef_server_url = "https://api.chef.io/organizations/<YOUR_ORG>"



While creating your user  on hosted chef, you must have downloaded your private key,Tell vagrant where to find the file:

chef.validation_key_path  =   ".chef/<YOUR_USER>.pem


Also,you  need to tell  Vagrant  which client it should use to validate itself  against in the Chef Server:


chef.validation_client_name  =  "<YOUR__USER>"


Finally,you should  tell vagrant how to name your node:

chef.node_name  = "server"


After configuring your Vagrantfile,all you need to do is run the basic vagrant commands such as vagrantup,vagrant provision and vagrant ssh.To stop your VM,just  run the halt command.


If you want to start from scratch again, you will have to destroy your VM and delete the node and client from chef server  by running the command:



local@workstation:~/chef-repo $  vagrant destroy 
local@workstation:~/chef-repo $  knife node delete server -y &&  knife client  delete server  -y