I like to use [[http://www.ansible.com/][Ansible]] to manage my personal
servers. It forces me to make the environment reproducible so I don't
have to care about a specific box: I can throw them away easily, knowing
I can get a new one when I need, with the exact same configuration.
I also find Ansible easier to reason about than Chef or Puppet. The fact
that I have to manage and maintain only a few machines is probably why.
When I develop on my personal projects, I use a lot of VMs, and that's
where [[http://www.vagrantup.com/][Vagrant]] enters the picture. Being
able to start a local VM and get a clean environment quickly is
invaluable to me. It makes it easy to test an application or library in
different situation, without carrying about local dependencies and
conflicts created by having multiple versions of the same library
installed on the system.
But sometimes a local VM is not enough, and you need a more powerful
server, so now you need an EC2 instance.
My goal with this article is to show how easy you can combine Vagrant
with Ansible to provision an EC2 instance.
** The basic
I have a private repository with all my rules for Ansible. But for this
post, all we need is a simple playbook. So let's start by creating a
directory named /vagrant/, and put inside a configuration file named
/playbook.yml/, with the following content:
#+BEGIN_HTML
<script src="https://gist.github.com/franckcuny/fae46135ad0f3581ce6b.js"></script>
#+END_HTML
What we're describing, is that for all the hosts in our inventory we
will use =sudo= to install the program =htop= using =apt-get= (yes, I
assume you're using a debian-based system, but you get the idea).
First, we will try the setup on a local box. If you don't already have a
Vagrant box installed, you can grab a new one by running
=vagrant box add precise64 http://files.vagrantup.com/precise64.box=.
Now we can add the configuration file named /Vagrantfile/ with this
content.
#+BEGIN_HTML
<script src="https://gist.github.com/franckcuny/aadd788101c08744a22a.js"></script>
#+END_HTML
This file says that we will use the box named /precise64/, located at
the given URL, and we want to provision it using Ansible, and the path
to the playbook.
By running =vagrant up=, a box gets started and provisioned. An
inventory file is generated for us inside the directory, so ansible will
know what to do. The output should be similar to this:
#+BEGIN_HTML
<script src="https://gist.github.com/franckcuny/e3df9a2424e4a4a12f60.js"></script>
#+END_HTML
As we can see, everything went well, and the application =htop= was
successfully installed. We can now run =vagrant ssh= and once logged
inside the VM, run =htop=.
** AWS
I've created a key pair for Vagrant in the AWS console. Note the access
and secret access keys, and download the SSH private key too. For this
article, we will put the key into the same directory as our playbook and
Vagrant's configuration.
We need to install a plugin for that:
=vagrant plugin install vagrant-aws=. We also need to modify our
/Vagrantfile/ to use a different box, and also add the configuration for
AWS.
#+BEGIN_HTML
<script src="https://gist.github.com/franckcuny/ac8cad84af5f51a923f6.js"></script>
#+END_HTML
We need to override the user name to /ubuntu/ and specify the path to
the private key (the one we got from the AWS console when we created our
new key pair) to log into the instance. The box also needs to be
overridden.
Running =vagrant up --provider=aws= will provision the box. It will
takes a few minutes to start the instance and run the provisioning part.
Wait a few minutes, but if it looks like the system is stuck, you can
re-run the previous command by exporting =VAGRANT_LOG=debug= in order to
get more detailed information.
#+BEGIN_QUOTE
If the provisioning blocks while trying to connect to ssh, it's
probably because your security group doesn't allow SSH connections.
#+END_QUOTE
Now =vagrant ssh= will dump you into the VM and you should be able to
run =htop=.
Don't forget to run =vagrant halt= and =vagrant destroy= once you're
done!
