exam

This is the exam task for IT Instastructure Services 2024 course.

Intro

Our application is ready to be released!

Today is the release day, link to Agama app was published in the Internet and you start to serve your first happy customers. You monitor all your insfastructure components and ready to react on any problems.

Of course everything that could go wrong -- goes wrong! Suddenly one of your DNS instances just died without any reason. While you were checking the logs one HAProxy crashed! And Docker containers with Agama app just start to disappear!

Luckily, you did a great job in the last few months to build fault-tolerant infrastructure and happy customers didn't notice any problems with Agama app during that time. Great job, you got many benefits and congratulations. But the most important thing: now you can tell everyone that you sucessfully finished "IT Infrastructure services" course in TalTech.

Sounds great?

There is one last step though -- put all the bits and pieces together to build this infrastructure one last time.

Infrastructure

You will have 3 virtual machines to use: use "-1" and "-2" for the main application stack, "-3" for internal services.

Each application stack machine should have these services set up and running:

• Agama in the Docker containers
• HAProxy
• Keepalived
• MySQL (master on "-1" machine, replica on "-2")
• Secondary Bind
• Prometheus exporters

Remaining machine should have these services set up and running:

• Primary Bind
• InfluxDB
• Telegraf
• Agama-client
• Prometheus
• Grafana
• Nginx as frontend for Grafana and Prometheus

Differences with previous tasks

We tried to make this infrastructure as similar as possible to what you did during the course, however there are a few differences worth pointing out.

There is one primary Bind and two secondary Binds now; don't add primary address to /etc/resolv.conf -- only both secondary addresses. For example, in this setup:

192.168.42.35   # Bind secondary
192.168.42.87   # Bind secondary
192.168.42.124  # Bind primary

/etc/resolv.conf could look like this:

nameserver 192.168.42.35
nameserver 192.168.42.87
search mydomain.tld

Put all your Nginx configuration to single file: sites-enabled/default. There should not be any other files in that folder.

Also, as there are three machines now, so your Grafana dashboards, backup scripts and documentation should reflect and support it.

Task

Read exam requirements here.

Update your Ansible playbook named infra.yaml to deploy the infrastructure described above.

Provide the backup SLA document (backup_sla.md) and backup restore instructions for every service that is being backed up (backup_restore.md).

Requirements

1. After the infrastructure is deployed, running ansible-playbook infra.yaml command again should not produce any changes on the managed hosts
2. Every variable should be defined exactly once -- in hosts, group_vars/all.yaml or some other file if you feel needed. If value can be retrieved from Ansible facts, it should be taken from there
3. No active plain text passwords should be found anywhere in your repository (including history); note that it's okay to have old passwords in the code -- but only if you changed them already
4. No IP addresses should be used in configurations, except Bind and Keepalived configuration and /etc/resolv.conf. Should you address local machine, use localhost -- not 127.0.0.1!
5. Your microphone and screen sharing should work in Discord calls

Presenting your solution

If you have run the Ansible command mentioned above, and it did not trigger any changes, you are ready to present your solution.

Here you can find more details on how we will test your submission.

But make sure to test it yourself first!

Good luck!