6-roles

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Although it is possible to write a playbook in one file as we’ve done throughout this workshop, eventually you’ll want to reuse files and start to organize things.

Ansible Roles are the way we do this. When you create a role, you deconstruct your playbook into parts and those parts sit in a directory structure. This is considered best practice and will save you a lot of time in the future.

For this exercise, you are going to take the playbook you just wrote and refactor it into a role.

Let’s begin with seeing how your iis-basic-playbook will break down into a role…

Section 1: Create directory structure for your new role

Step 1

In Visual Studio Code, navigate to explorer and your WORKSHOP_PROJECT section where you previously made iis_advanced.

Select the iis_advanced folder.

Create a directory called roles by right-clicking on iis_advanced and selecting New Folder

Now right-click roles and create a new folder underneath called iis_simple.

Step 2

Within iis_simple create new folders as follows:

• defaults

• vars

• handlers

• tasks

• templates

Step 3

Within each of these new folders (except templates), right-click and create New File Create a file called main.yml in each of these folders. You will not do this under templates as we will create individual template files. This is your basic role structure and main.yml will be the default file that the role will use for each section.

The finished structure will look like this:

Section 2: Breaking Your site.yml Playbook into the Newly Created iis_simple Role

In this section, we will separate out the major parts of your playbook including vars:, tasks:, template:, and handlers:.

Step 1

Make a backup copy of site.yml, then create a new site.yml.

Navigate to your iis_advanced folder, right click site.yml, click rename, and call it site.yml.backup

Create a blank new file called site.yml in the same folder

Step 2

Update site.yml to look like to only call your role. It should look like below:

    ---
    - hosts: windows
      name: This is my role-based playbook

      roles:
        - iis_simple

Step 3

Add a default variable to your role. Edit the roles\iis_simple\defaults\main.yml as follows:

    ---
    # defaults file for iis_simple
    iis_sites:
      - name: 'Ansible Playbook Test'
        port: '8080'
        path: 'C:\sites\playbooktest'
      - name: 'Ansible Playbook Test 2'
        port: '8081'
        path: 'C:\sites\playbooktest2'

Step 4

Add some role-specific variables to your role in roles\iis_simple\vars\main.yml.

    ---
    # vars file for iis_simple
    iis_test_message: "Hello World!  My test IIS Server"

Note

Hey, wait… did we just put variables in two seperate places?

Yes… yes we did. Variables can live in quite a few places. Just to name a few:

• vars directory
• defaults directory
• group_vars directory
• In the playbook under the vars: section
• In any file which can be specified on the command line using the --extra_vars option
• On a boat, in a moat, with a goat (disclaimer: this is a complete lie)

Bottom line, you need to read up on variable precedence to understand both where to define variables and which locations take precedence. In this exercise, we are using role defaults to define a couple of variables and these are the most malleable. After that, we defined some variables in /vars which have a higher precedence than defaults and can’t be overridden as a default variable.

Step 5

Create your role handler in roles\iis_simple\handlers\main.yml.

    ---
    # handlers file for iis_simple
    - name: restart iis service
      win_service:
        name: W3Svc
        state: restarted
        start_mode: auto

Step 6

Add tasks to your role in roles\iis_simple\tasks\main.yml.

    ---
    # tasks file for iis_simple

    - name: Install IIS
      win_feature:
        name: Web-Server
        state: present

    - name: Create site directory structure
      win_file:
        path: "{{ item.path }}"
        state: directory
      with_items: "{{ iis_sites }}"

    - name: Create IIS site
      win_iis_website:
        name: "{{ item.name }}"
        state: started
        port: "{{ item.port }}"
        physical_path: "{{ item.path }}"
      with_items: "{{ iis_sites }}"
      notify: restart iis service

    - name: Open port for site on the firewall
      win_firewall_rule:
        name: "iisport{{ item.port }}"
        enable: yes
        state: present
        localport: "{{ item.port }}"
        action: Allow
        direction: In
        protocol: Tcp
      with_items: "{{ iis_sites }}"

    - name: Template simple web site to iis_site_path as index.html
      win_template:
        src: 'index.html.j2'
        dest: '{{ item.path }}\index.html'
      with_items: "{{ iis_sites }}"

    - name: Show website addresses
      debug:
        msg: "{{ item }}"
      loop:
        - http://{{ ansible_host }}:8080
        - http://{{ ansible_host }}:8081

Step 7

Add your index.html template.

Right-click roles\iis_simple\templates and create a new file called index.html.j2 with the following content:

    <html>
    <body>

      <p align=center><img src='http://docs.ansible.com/images/logo.png' align=center>
      <h1 align=center>{{ ansible_hostname }} --- {{ iis_test_message }}</h1>

    </body>
    </html>

Now, remember we still have a templates folder at the base level of this playbook, so we will delete that now. Right click it and Select Delete.

Step 8: Commit

Click File → Save All to ensure all your files are saved.

Click the Source Code icon as shown below (1).

Type in a commit message like Adding iis_simple role (2) and click the check box above (3).

Click the synchronize changes button on the blue bar at the bottom left. This should again return with no problems.

Section 3: Running your new playbook

Now that you’ve successfully separated your original playbook into a role, let’s run it and see how it works. We don’t need to create a new template, as we are re-using the one from Exercise 5. When we run the template again, it will automatically refresh from git and launch our new role.

Step 1

Before we can modify our Job Template, you must first go resync your Project again. So do that now.

Step 2

Select TEMPLATES

Note

Alternatively, if you haven’t navigated away from the job templates creation page, you can scroll down to see all existing job templates

Step 3

Click the rocketship icon for the IIS Advanced Job Template.

Step 4

When prompted, enter your desired test message

If successful, your standard output should look similar to the figure below. Note that most of the tasks return OK because we’ve previously configured the servers and services are already running.

When the job has successfully completed, you should see two URLs to your websites printed at the bottom of the job output. Verify they are still working.

Section 5: Review

You should now have a completed playbook, site.yml with a single role called iis_simple. The advantage of structuring your playbook into roles is that you can now add reusability to your playbooks as well as simplifying changes to variables, tasks, templates, etc.

Ansible Galaxy is a good repository of roles for use or reference.

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