Vagrant <3's Ansible
Our first big goal is to see if we can use Ansible to setup, or provision, an entire server that can run our MooTube app. To setup an empty VM, we'll use Vagrant with VirtualBox.
So before we start, make sure that you have VirtualBox installed: it's different for each OS, but should - hopefully - be pretty easy. Next, make sure you have Vagrant: it has a nice installer for every OS. On my Mac, surprise! I installed Vagrant via brew.
As long as you can type:
vagrant -v
you're good to go.
Vagrantfile Setup!
If you're new to Vagrant, it's a tool that helps create and boot different virtual machines, usually via VirtualBox behind the scenes. It works by reading a configuration file... which we don't have yet. Let's generate it!
vagrant init ubuntu/trusty64
That just created a file - Vagrantfile - at the root of our project that will boot a VM using an ubuntu/trusty64 image. That's not the newest version of Ubuntu, but it works really well. You're free to use a different one, but a few commands or usernames and passwords might be different!
Tip
If you want to use the latest Ubuntu 18.04 LTS release, you'll need a few tweaks:
1) Change the VM box in Vagrantfile to:
# Vagrantfile
Vagrant.configure("2") do |config|
# ...
config.vm.box = "ubuntu/bionic64"
# ...Or ubuntu/xenial64 in case you're interested in Ubuntu 16.04 LTS release.
2) Ubuntu 18.04/16.04 requires a private SSH key to be specified instead of a simple
password to login via SSH - Ansible can't log in into the server using just a username and
password pair. Also, the Ansible user should be set to vagrant. You can specify all this
information in the hosts.ini file for the VirtualBox host:
# ...
[vb]
192.168.33.10 ansible_user=vagrant ansible_ssh_private_key_file=./.vagrant/machines/default/virtualbox/private_key
# ...Make sure to uncomment private_network configuration as we did below in this code block
to be able to connect to the 192.168.33.10 IP.
3) Notice, that Ubuntu 18.04/16.04 has the new pre-installed Python 3. In case you have an error related to Python interpreter, specify the path to its binary explicitly as:
# ...
[vb]
192.168.33.10 ansible_user=vagrant ansible_ssh_private_key_file=./.vagrant/machines/default/virtualbox/private_key ansible_python_interpreter=/usr/bin/python3
# ...4) Ubuntu 18.04/16.04 doesn't come with aptitude pre-installed, so you will need to install it first
if you want to use the safe upgrade option for installed packages - we will talk about it later
in this course. Just add one new task to your playbook before upgrading:
# ansible/playbook.yml
---
- hosts: vb
# ...
tasks:
# ...
- name: Install aptitude
become: true
apt:
name: aptitude
- name: Upgrade installed packages
become: true
apt:
upgrade: safe
# ...Boot that VM!
With that file in place, let's boot the VM!
vagrant up
Then... go make a sandwich! Or run around outside! Unless you've run this command before, it'll need to download the Ubuntu image... which is pretty huge. So go freshen up your cup of coffee and come back.
Thanks to the power of video, we'll zoom to the end! Zooooom!
When it finishes, make sure you can SSH into it:
vagrant ssh
With any luck, you'll step right into your brand new, basically empty, but totally awesome, Ubuntu virtual machine.
By the way, Vagrant stores some info in a .vagrant directory. In a real project, you'll probably want to add this to your .gitignore file:
| // ... lines 1 - 17 | |
| /.vagrant/ |
Setup an External IP Address
Our goal is to have Ansible talk to this new VM. For that, we need a dependable IP address for the VM. Check out the Vagrantfile that was generated automatically for us: it has a section about a "private network". Uncomment that!
| // ... lines 1 - 7 | |
| Vagrant.configure("2") do |config| | |
| // ... lines 9 - 26 | |
| # 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" | |
| // ... lines 30 - 72 |
This will let us talk to the VM via 192.168.33.10.
For that to take effect, run:
vagrant reload
Tip
If you're inside the VM, for stepping out of it simply run:
exit
That should take just a minute or two. Perfect! And now we can ping that IP!
ping 192.168.33.10
Configuring the new Ansible Host
The VM represents a new host. And that means we need to add it to our hosts file! In hosts.ini, let's keep the local group and add another called vb, for VirtualBox. Under there, add the IP: 192.168.33.10:
| // ... lines 1 - 3 | |
| [vb] | |
| 192.168.33.10 | |
| // ... lines 6 - 7 |
We know that as soon as we make this change, we should be able to use the vb host:
ansible vb -m ping -i ansible/hosts.ini
That should work, right? It fails! The ping module does a bit more than just a ping, and in this case, it's detecting that Ansible can't SSH into the machine. The reason is that we haven't specified a username and password or key to use for SSH.
Configuring SSH Properly
To see what I mean, try SSH'ing manually - the machine is setup with a vagrant user:
ssh vagrant@192.168.33.10
Woh! Our first error looks awesome!
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
You may or may not get this error. Since I've used Vagrant in this same way in the past, it's telling me that last time I SSH'ed to this IP address, it was a different machine! We know that's ok - there's nothing nefarious happening. To fix it, I just need to find line 210 of my known_hosts file and remove the old fingerprint. I'll do that and save. Try it again:
ssh vagrant@192.168.33.10
It saves the fingerprint and then asks for a password. The password for the image that we're using is vagrant. That's pretty standard, but it might be different if you're using a different image.
Tip
If you still see an error like:
vagrant@192.168.33.10: Permission denied (publickey).
It seems like the server requires a private SSH key file to be specified. Try to specify it as an identity file:
ssh vagrant@192.168.33.10 -i ./.vagrant/machines/default/virtualbox/private_key
We're inside! So, how can we tell Ansible to SSH with username vagrant and password vagrant? The answer is... not surprising! These are two more variables in your hosts inventory file: ansible_user set to vagrant and ansible_ssh_pass=vagrant:
| // ... lines 1 - 3 | |
| [vb] | |
| 192.168.33.10 ansible_user=vagrant ansible_ssh_pass=vagrant | |
| // ... lines 6 - 7 |
Try the ping again:
ansible vb -m ping -i ansible/hosts.ini
Tip
If you still can't SSH into the Vagrant box with Ansible using a simple username/password pair and continue getting an error like:
192.168.33.10 | FAILED! => {
"msg": "to use the 'ssh' connection type with passwords, you must install the sshpass program"
}Try to specify the SSH private key instead of password. For this, change the line to:
# ...
[vb]
192.168.33.10 ansible_user=vagrant ansible_ssh_private_key_file=./.vagrant/machines/default/virtualbox/private_key
# ...Eureka! But, quick note about the SSH password. If this weren't just a local VM, we might not want to store the password in plain text. Instead, you can use a private key for authentication, or use the Ansible "vault" - a cool feature that lets us encrypt secret things, like passwords. More on that later.
But for now, our setup is done! We have a VM, and Ansible can talk to it. Next, we need to create a playbook that's capable of setting up the VM.
Hi!
Is possible that you have a error like this when you exec $ ansible vb -m ping -i ansible/hosts.ini:
[Solution]
brew install https://raw.githubusercontent.com/kadwanev/bigboybrew/master/Library/Formula/sshpass.rb