Ansible: Roles

Use Ansible roles to orchestrate more complex configurations.Let's create a new directory named nginx, which will be a Role. Then we'll create the basic structure of a Role:

mkdir -p roles/nginx cd roles/nginx mkdir files handlers meta templates tasks vars

Meta

We'll start with the meta information:

This meta/main.yml file creates a dependency on the "sslcertificates" role:

--- dependencies: - { role: sslcertificates }

However we don't have a dependency currently, so our meta data file looks like this:

Files

I grab Nginx configuration from H5Bp.

cd roles/nginx/files # Get the H5BP Nginx repository wget https://github.com/h5bp/server-configs-nginx/archive/master.zip # Save the "h5bp" directory and discard the rest unzip master.zip rm master.zip mv server-configs-nginx/h5bp ../ rm -rf server-configs

Now we have files roles/nging/files/h5bp.

Use Ansible roles to orchestrate more complex configurations.Let's create a new directory named nginx, which will be a Role. Then we'll create the basic structure of a Role:

mkdir -p roles/nginx
cd roles/nginx
mkdir files handlers meta templates tasks vars

Meta

We'll start with the meta information:

This meta/main.yml file creates a dependency on the "sslcertificates" role:

---
dependencies:
 - { role: sslcertificates }

However we don't have a dependency currently, so our meta data file looks like this:

---
dependencies: []

Files

I grab Nginx configuration from H5Bp.

cd roles/nginx/files

# Get the H5BP Nginx repository
wget https://github.com/h5bp/server-configs-nginx/archive/master.zip

# Save the "h5bp" directory and discard the rest
unzip master.zip
rm master.zip
mv server-configs-nginx/h5bp ../
rm -rf server-configs

Now we have files roles/nging/files/h5bp.

Variables

Next we'll add some variables to be used in this role. Create roles/nginx/vars/main.yml.

--- domain: serversforhackers.com

Templates

We'll create an Nginx configuration file using templates. Templates let us create a file which contain variables, loops and other items as allowed in Python's Jinja2 template engine.

I create file roles/nginx/templates/serversforhackers.com.j2 to create the Jinja2 Nginx configuration template for the serversforhackers.com site.

server { listen 80; server_name *.{{ domain }}; return 301 http://{{ domain }}; } server { listen 80 default_server; root /var/www/{{ domain }}; index index.html index.htm; access_log /var/log/nginx/{{ domain }}.log; error_log /var/log/nginx/{{ domain }}-error.log error; server_name {{ domain }}; charset utf-8; include h5bp/basic.conf; location /favicon.ico { log_not_found off; access_log off;} location /robots.txt { log_not_found off; access_log off;} location / { try_files $uri $uri =404; } }

Handler

Create some handlers. Create file roles/nginx/handlers/main.yml:

--- - name: Start Nginx service: name=nginx state=started - name: Reload Nginx service: name=nginx state=reloaded

Tasks

Finally we put everything together in our tasks file. Create file roles/nginx/tasks/main.yml:

--- - name: Add Nginx Repository apt_repository: repo='ppa:nginx/stable' state=present - name: Install Nginx apt: pgk=nginx state=latest update_cache=true notify: - Start Nginx - name: Add H5BP Config copy: src=h5bp dest=/etc/nginx owner=root group=root - name: Disable Default Config file: dest=/etc/nginx/sites-enabled/defalt state=absent notify: - Reload Nginx - name: Add SFH Site Config template: src=serversforhackers.com.j2 dest=/etc/nginx/sites-available/{{ domain }} owner=root group=root - name: Enable SFH Site Config file: src=/etc/nginx/sites-available/{{ domain }} dest=/etc/nginx/sites-enabled/{{ domain }} state=link notify: - Reload Nginx

Test, Debug and Run Role

Finally we can try running this Role. In the same directory as the roles directory, create a new yaml file such as run.yml. In this video, I use file nginx.yml since we only use the Nginx role:

--- - hosts: web sudo: yes user: root roles: - nginx

We can run this Playbook like so:

ansible-playbook --private-key=~/.ssh/id_ansible nginx.yml

Let's do a syntax check, which you should run before trying out a playbook or role:

ansible-playbook --syntax-check nginx.yml

We get some errors in the video, however I've corrected all of them in the above tasks/main.yml file.