Ansible/Playbooks
From charlesreid1
Example: Secure Nginx Server
This page walks through a procedure resulting in the following files:
playbooks/ansible.cfg
playbooks/hosts
playbooks/Vagrantfile
playbooks/web-notls.yml
playbooks/web-tls.yml
playbooks/files/nginx.key
playbooks/files/nginx.crt
playbooks/files/nginx.conf
playbooks/templates/index.html.j2
playbooks/templates/nginx.conf.j2
Before you begin: Vagrant configuration
This assumes we will be setting up a Ubuntu machine using Vagrant. (See Vagrant page for steps.)
Before starting, we want to remap some ports.
We want to arrange the Vagrant machine so that we map the local port 8080 to the vagrant machine's port 80, and map the local port 8443 to the vagrant machine's port 443.
The Vagrantfile is a Ruby file that specifies how to start up and set up the Vagrant boxes. The Vagrantfile should be modified as follows:
VAGRANTFILE_API_VERSION = "2" Vagrant.configure(VAGRANTFILE_API_VERSION) do |config| config.vm.box = "ubuntu/xenial64" config.vm.network "forwarded_port", guest: 80, host: 8080 config.vm.network "forwarded_port", guest: 443, host: 8443 end
Now instruct vagrant to reload from the Vagrantfile:
$ vagrant reload
==> default: Forwarding ports...
default: 80 => 8080 (adapter 1)
default: 443 => 8443 (adapter 1)
default: 22 => 2222 (adapter 1)
Creating a simple playbook
The following simple playbook will set up an nginx web server on our fresh Ubuntu machine.
The Pieces
Here are the pieces in our playbook:
- The playbook itself (YAML file)
- nginx configuration file
- nginx HTML templates
- Create Ansible group webservers
The Playbook: YAML file
Here is a simple playbook for our secure nginx server:
web-notls.yml:
- name: Configure webserver with nginx
hosts: webservers
become: True
tasks:
- name: install nginx
apt: name=nginx update_cache=yes
- name: copy nginx config file
copy: src=files/nginx.conf dest=/etc/nginx/sites-available/default
- name: enable configuration
file: >
dest=/etc/nginx/sites-enabled/default
src=/etc/nginx/sites-available/default
state=link
- name: copy index.html
template: src=templates/index.html.j2 dest=/usr/share/nginx/html/index.html
mode=0644
- name: restart nginx
service: name=nginx state=restarted
Required files: /etc/nginx/sites-available/default, /usr/share/nginx/html/index.html
YAML truth-y values: true, True, TRUE, yes, Yes, YES, on, On, ON, y, Y
YAML false-y values: false, False, FALSE, no, No, NO, off, Off, OFF, n, N
nginx config file
Here is the corresponding nginx configuration file, which we put in files/nginx.conf:
files/nginx.conf:
server {
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;
root /usr/share/nginx/html;
index index.html index.htm;
server_name localhost;
location / {
try_files $uri $uri/ =404;
}
}
nginx index html page
Likewise, we want to create an index page for nginx to serve up, and we want to put template files into the playbook directory, in the templates subdirectory.
(NOTE: .j2 extension means it is a Jinja 2 template)
playbooks/templates/index.html.j2
<html>
<head>
<title>Welcome to ansible</title>
</head>
<body>
<h1>nginx, configured by Ansible</h1>
<p>If you can see this, Ansible successfully installed nginx.</p>
<p>Running on {{ inventory_hostname }}</p>
</body>
</html>
Creating webservers Ansible group
We will create a webservers Ansible group in the inventory file and refer to this group in the Ansible playbook.
In the playbooks/hosts file the "myvagrantbox" line is put under the heading [webservers]:
playbooks/hosts
[webservers] myvagrantbox ansible_host=127.0.0.1 ansible_port=2222
Now test it out: ping the webservers group with a single command:
$ ansible webservers -m ping
Output:
testserver | success >> {
"changed": false,
"ping": "pong"
}
Running a simple playbook
The ansible-playbook command is used to execute playbooks:
ansible-playbook web-notls.yml
Alternatively, to run a playbook directly, use the shebang line:
#!/usr/bin/env ansible-playbook
Then execute it directly:
./web-notls.yml