Project - Linux automation

To further enhance your Ansible skills, let's deploy the monitoring tool Grafana to one of the nodes in the demo environment.

Objective

Create an Ansible project from scratch and automate some basic linux configurations.

Guide

Step 1 - Prepare project

Create a new project folder in your home directory:

[student@ansible-1 ~]$ mkdir grafana-deployment

Create an inventory file with a grafana group definition. You will deploy Grafana to one of the nodes in the lab environment. Copy the node2 configuration from the default inventory file to your grafana group.
Create a small Ansible configuration file (ansible.cfg) and instruct Ansible to always use the inventory you just created.

For example, you may check your inventory with the ansible-inventory CLI utility. In this case, the host has an alias of grafana-instance1 which is part of a group grafana:

[student@ansible-1 ~]$ ansible-inventory --graph --vars
@all:
  |--@ungrouped:
  |--@grafana:
  |  |--grafana-instance1
  |  |  |--{ansible_host = node2.example.com}

Hint

As you can see above, no inventory was provided in the CLI call (e.g. with -i inventory), but the correct inventory is used.

Achieve the following tasks:

Inventory file created
Configuration file created which sets the correct inventory source

Step 2 - Install Grafana

The Grafana package comes from a dedicated repository, you'll need to enable it for the yum package manager on node2. Use the following file and copy it to /etc/yum.repos.d/grafana.repo with an Ansible task:

[grafana]
name=grafana
baseurl=https://packages.grafana.com/oss/rpm
repo_gpgcheck=1
enabled=1
gpgcheck=1
gpgkey=https://packages.grafana.com/gpg.key
sslverify=1
sslcacert=/etc/pki/tls/certs/ca-bundle.crt

The next task should install the grafana package. Another task is needed to start (and enable) the grafana-server service.

Achieve the following tasks:

Running Grafana instance on node2
Grafana service running and enabled at startup

Ensure that Grafana is running with an ad hoc command:

[student@ansible-1 grafana-deployment]$ ansible grafana -a "systemctl status grafana-server"
node2 | CHANGED | rc=0 >>
● grafana-server.service - Grafana instance
   Loaded: loaded (/usr/lib/systemd/system/grafana-server.service; enabled; vendor preset: disabled)
   Active: active (running) since Sun 2022-04-17 10:00:35 UTC; 2min 44s ago
     Docs: http://docs.grafana.org
 Main PID: 20887 (grafana-server)
    Tasks: 7 (limit: 4579)
   Memory: 97.7M
   CGroup: /system.slice/grafana-server.service
           └─20887 /usr/sbin/grafana-server --config=/etc/grafana/grafana.ini --pidfile=/var/run/grafana/grafana-server.pid --packaging=rpm cfg:default.paths.logs=/var/log/grafana cfg:default.paths.data=/var/lib/grafana cfg:default.paths.plugins=/var/lib/grafana/plugins cfg:default.paths.provisioning=/etc/grafana/provisioning

Nice, the Grafana package is installed and the service is running!
Grafana has a nice UI, unfortunately, the UI currently can't be viewed directly in the Red Hat Demo environment!

This is how it would look, on the left in the default dark theme, the right screenshot shows the light theme.

Success

You can use the following playbook to check the current theme setting, create a new file, paste to content and run it:

- name: Test Grafana theme setting
  hosts: node2
  vars:
    # By default, Grafana listens on port 3000!
    # Change the value to '8080' if you want to check the target port later on
    grafana_port: 3000
  tasks:
    - name: Get Grafana UI content
      ansible.builtin.uri:
        url: http://node2:{{ grafana_port }}
        return_content: true
      register: grafana_ui_content

    - name: Output current theme setting
      ansible.builtin.debug:
        msg: "HTML body returns '{{ grafana_ui_content.content | replace('\n', '') | regex_replace('^(.*body class=\\\")(.*)( app-grafana.*)', '\\2') }}' as the current color setting."

NOT in the Red Hat Demo environment? Click me.

If you are in a local environment, you can use the default login credentials admin:admin, you can skip the password change request.
You can check if the UI is available by using the curl request curl -L node2:8080

[student@ansible-1 ansible_files]$ curl -L node2:8080
<!DOCTYPE html>
<html lang="en">
  <head>
    <script nonce="">

      !(function () {
        if ('PerformanceLongTaskTiming' in window) {
          var g = (window.__tti = { e: [] });
          g.o = new PerformanceObserver(function (l) {
            g.e = g.e.concat(l.getEntries());
          });
          g.o.observe({ entryTypes: ['longtask'] });
        }
      })();
    </script>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
    <meta name="viewport" content="width=device-width" />
    <meta name="theme-color" content="#000" />

    <title>Grafana</title>

    <base href="/" />

    <link
      rel="preload"
      href="public/fonts/roboto/RxZJdnzeo3R5zSexge8UUVtXRa8TVwTICgirnJhmVJw.woff2"
      as="font"
      crossorigin
    />

    <link rel="icon" type="image/png" href="public/img/fav32.png" />
    <link rel="apple-touch-icon" sizes="180x180" href="public/img/apple-touch-icon.png" />
    <link rel="mask-icon" href="public/img/grafana_mask_icon.svg" color="#F05A28" />
    <link rel="stylesheet" href="public/build/grafana.dark.3b87c7ad03e52dfc5e30.css" />

    <script nonce="">
      performance.mark('frontend_boot_css_time_seconds');
    </script>

    <meta name="apple-mobile-web-app-capable" content="yes" />
    <meta name="apple-mobile-web-app-status-bar-style" content="black" />
    <meta name="msapplication-TileColor" content="#2b5797" />
    <meta name="msapplication-config" content="public/img/browserconfig.xml" />
  </head>

  <body class="theme-light app-grafana">
    <style>
      .preloader {
        height: 100%;
        flex-direction: column;
        display: flex;
        justify-content: center;
        align-items: center;
      }
  ...<cut for readability>...

Step 3 - Configure Grafana

By default, Grafana provides the webinterface on port 3000 and uses a dark background.
You need to adjust the Grafana configuration with Ansible to instruct the service to show the webinterface on port 8080 and to configure a white background (the so-called light theme).

The configuration for Grafana is stored in /etc/grafana/grafana.ini. You need to adjust the theme configuration in the users section, as well as the http_port in the server section. Take a look at the Grafana documentation on how to change the parameters.
Naturally, you should achieve this with Ansible! Find an appropriate module (there is more than one way to achieve the solution...) and adjust the Grafana configuration file.

Tip

Configuration changes require a service restart!

Tip

Login to node2 via ssh, take a look at the file. You can download the file from there, copy the content or just take a look at how it looks to be able to find the appropraiate lines to change, there are many ways to achieve the solution!

Yesterday you started an Apache webserver on port 8080 with Ansible. Two services (Apache/Httpd and Grafana) can not use the same port!.

Warning

There should be no running Apache webserver on node2, if Apache is running, you'll need to stop httpd on node2! If the port is occupied, Grafana can not be started!
You could (and should!) ensure a stopped Apache easily with an Ansible task...

After adjusting the configuration, run the playbook above (which checks the Grafana UI theme settings), adjust the grafana_port variable to use the new port 8080.

Achieve the following tasks:

Accessible Grafana UI on port 8080
Grafana UI in light theme
Bonus: Can you manage to control the look of Grafana by just switching a variable?

Step 4 - Re-format project to role structure

All Ansible projects should use the role structure, if your project does not already uses it, now is the time to rearrange your content. Create a roles folder and an appropriately named sub-folder for the grafana deployment with all necessary folder and files.
Change your playbook to use your role, e.g.:

---
# This is the main Playbook for the 'Grafana Deployment' Project

- name: Deploy Grafana instance
  hosts: grafana
  roles:
    - grafana

Make sure everything works by executing your playbook again, you should not see any changes, all tasks should return a green "Ok" status.

Achieve the following tasks:

Project uses Ansible role structure
Playbook references role

Step 5 - Bonus: Upload project to Github

Create a new project in your personal Github account and commit your Ansible project.

Step 6 - Bonus: Run your project within AAP

Create a new project in AAP, reference your Grafana project from Github as the code source. Create a template and run your playbook.