Installing NGINX OSS webserver with Ansible - Part 2

This is part three of me walking through a simple demo that I set up using Ansible.

This installment installs the web server machines using NGINX OSS.

Please refer back to the first two installments to get an understanding of the assumptions: local file system inventory files, Ansible host deployed to the same VPC as the remote machines, variable files, run the playbooks from the same folder as the inventory and variable files.

The playbook

In this example I will focus on the playbook: https://github.com/brianehlert/ansible-nginx-examples/blob/master/nginx_web_demo_oss.yaml

As the previous blog, this uses the nginx Ansible Role.

This time, I have included the 'extra_vars' - extra variables specific to this playbook, within the playbook itself instead of using an external file.

The reason is did this was to follow a different pattern and that this is a static playbook for me.  The only substitution that I am doing involves the individual webserver machines that this particular configuration is applied to.

The play uses the default.conf Jinja2 template for an http server from the Ansible Role.
I am placing the configuration in the default location, setting an error page location.
Instructing it to respond to traffic from any IP address, on port 80.
And lastly I am setting the path and file for the page to be demo_index.html

(you will also find demo_index.html in the example repository along side this file).

Running the playbook:
ansible_playbook nginx_web_demo_oss.yaml -i webservers

The result

Like my previous post, we aren't done yet.  So another error message.
This time the error message that you should receive is no longer 'an error occurred' but rather '403 forbidden'

Why '403 forbidden' you might ask?  Because we configured a file path for the HTML file.
The path we set is: /usr/share/nginx/html/demo_index.html
But there is not a file at that path.  As far as the web server knows, you can't access whatever you are requesting.  So the 403 because it is a configured path instead of a 404 which you would get against a path that does not exist.

Fixing the 403

I thought I would be nice and fix the 403 in this blog post, so here is the solution.

ansible-playbook update_demo_index.html.yaml -i webservers

This is another simple playbook; https://github.com/brianehlert/ansible-nginx-examples/blob/master/update_demo_index_html.yaml

It simply copies the file demo_index.html to the correct path on each webserver.

Now, if you refresh your browser that you are using to test the loadbalancer, you should get an NGINX Demo page.

Why so granular

One reason for being so granular with the playbooks is to separate the tasks that are being performed.
The benefit is that the playbooks can be reused in other playbooks, like functions.  Another benefit is that they align with how Roles should be created, as reusable tasks.

If you get into using Ansible Tower, you can start linking together playbooks into a workflow - branching off for success and failure conditions.  Even adding pauses for approval workflows.