DevOps Fundamentals: Build Azure Infra with Terraform

Understand the core fundamentals of terraform, how it is different from Cloud native tool like cloudformation from AWS, ARM for Azure or deployment manager from Google.

Learn the nuances of Terraform to use it as a Infrastructure as Code to provision and manage any cloud, infrastructure, or service. This module will be about the evolution of terraform and get a sound knowledge of the lifecycle covering INIT , PLAN , APPLY and DESTROY.

Installing terraform on different operating system, easy installation on Linux and then on windows and Mac. Learn about terraform cli and get ready to write terraform configuration.

Test your basic terraform knowledge

Terraform users define infrastructure in a simple, human-readable configuration language called HCL (HashiCorp Configuration Language). In this module we will be writing our first terraform configuration file and will start with creating a resource group on Azure. We then apply the lifecycle by initializing and then applying our infrastructure.

In the first half of the video we would be creating resources on Azure .

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Congratulations on writing your first configuration however what you have is hard coding the attributes in the configuration and this is not the most practical or efficient if we have to change these values. In order to address the issue we are going to parameterize our configuration using variables.

There are multiple ways of parametrizing variables, following are the ones which we have practised in this video:

1. Defining in variable.tf

2. Command line flags

3. Using a file >> *.auto.tfvars

What is terraform state? Why should you care about it. In this module you’ll learn the heart where all the data of terraform seats in, state acts as a database for terraform so that it can understand what all resources are created using terraform and what next to create/modify/delete.

Understand how to isolate state and keep it safe so that it is secured and easily accessible when working within a team. Learn how to manage resource using terraform state like deprovisioning resources using Terraform state.

Terraform State and Config Practise

Terraform is a declarative language, generally declarative languages done have for-loops to repeat a block of logic fortunately terraform provides a few of the primitives like count, for_each and for expressions which allows us to loop over lists,sets and maprs. In this module we would be using a for-each loop on a set of NSG rules which we think would be a top example when it comes to implementing for-each loops in real life scenarios as well.

We would interate sing for_each loop also use count parameter to create multiple resources, in this module we would use for loop to generate a single value wherein we would be iterating through the list using for to generate certain values.

Count Parameter

Now that you know how to create single resource like resource group, cosmost db however in real scenarios in your companies you would be need to create multiple resources using the piece of code and terraform resources has a meta-parameter which we will use called “count.” Count is one of the oldest iteration construct that is used to create multiple copies of resources using the same code.

We will create multiple blob storages in azure using the count parameter with different unique names for all of the resources created using count.index

We would also be using terraforms build in function called length which will be used to count the number of items in the given list and then use the value to assign it to count to define number of resources to be created.

Conditionals

Terraform not only offer multiple ways to perform looping, there are also several ways to do conditionals just like if statement in other programming languages, using conditionals you perform certain action basis if the logic is true or false.

Terraform Functions

Just like other programming function is a block of reusable code performs certain operations, terraform includes a number of built in functions that can be called within expression to transform values like max() will pick the max from the set. We would be using multiple functions like element(),min(),format() and many more and understand how we can leverage functions in real world while building infrastructure.

Practise how loops and count works in terraform.

We would be building a multi tier application with multiple virtual machines using count function wherein we would be building multiple components like:

1. Virtual machines

2. Virtual Networks

3. Subnets

4. Multiple Public Ip addresses

Terraform isn’t just to manage your infrastructure it can be also used as a configuration management tool like Puppet, Chef,or Ansible which means you can you use your existing management modules, roles, or cookbooks that already know how to build your applications and services. This module is going to be about how you can use terraform provisioner to bootstrap an apache server.

We are going to use three different provisioners i.e. file, local-exec and remote-exec to write our configuration code to install and apache on a new Virtual Machine.

Terraform module is a very simple approach to combine set of terraform configuration file wrapping infrastructure in a folder as a module, in this section we would get started and understand the core fundamentals of terraform module, what it is, why should you care about using terraform Module.

This sections is going to be an hands on session with terraform module, we would use terraform registry to create an Azure VNET, this module is a publicly available module which any one can pull and start creating resources.

If you were to create same infrastructure for multiple environments or let's say for multiple clients, because underlying infrastructure would remain same, how would you do it?well copying pasting is error prone, that can't be the solution. Watch out the video to learn.

Reuse your existing Terraform code to spin up multiple environments.

GitHub Actions makes it easy to automate all of our software/Infrastructure workflows with world-class CI/CD. Build, test, and deploy your Infrastructure code right from GitHub.

So far we have been deploying code from our local system, downside of this approach is no one is where who applied the changes and from where, in this section we would be leveraging Github Actions to deploy terraform code.

Encrypted  Azure secrets which allows you to store sensitive information in your organization, repository, or repository environments.

We would be deploying infrastructure on Azure using the Terraform Code via Azure DevOps.

Terraform Import

Terraform import is being used in this video to bring existing environment which is not build via terraform and might have been built via some other means like powershell, bash, ansible. Infrastructure built using these tools can be brought under terraform management to manage/delete those resources as well using terraform.

Data

Data sources in terraform allows us to fetch details of existing resourced defined outside terraform.

Terraform 0.15 ships with improved logging behavior, extends value sensitivity to provider attributes, allowing provider developers to help protect values from being printed to the console. We would be covering both of these features.