Steps to install terraform on Ubuntu / Ubuntu cloud server :

 1.       Install unzip

sudo apt-get install unzip

2.  Download latest version of the terraform (substituting newer version number if needed)

wget https://releases.hashicorp.com/terraform/1.0.7/terraform_1.0.7_linux_amd64.zip

3.  Extract the downloaded file archive

unzip terraform_1.0.7_linux_amd64.zip

4. Move the executable into a directory searched for executables

sudo mv terraform /usr/local/bin/

5. Run it

terraform --version

CREATE EC2 WITH TERRAFORM

To create an EC2 instance with Terraform using the provided AWS credentials, follow these steps. Be sure to replace the placeholder values with your actual credentials and ensure your credentials are kept secure.

Step 1: Setup Terraform Project Directory

1. Create a Project Directory:

mkdir my-ec2-instance

cd my-ec2-instance

 

2.      Create main.tf File: Open your favorite text editor and create a file named main.tf.

Step 2: Define the AWS Provider and EC2 Instance

In the main.tf file, define the AWS provider and the EC2 instance resource:

# main.tf

# Define the AWS provider
provider "aws" {
  region     = "us-east-1"
  access_key = "AKIAU6GDXLT5RR3WZ755"
  secret_key = "4pllcY6LbEkPJHCpqwZUUq7C6+dqui6HDQY1srcF"
}

# Define the EC2 instance resource
resource "aws_instance" "example" {
  ami           = "ami-04b70fa74e45c3917"
  instance_type = "t2.micro"

  tags = {
    Name = "ExampleInstance"
  }
}

2.       Initialize Terraform: Initialize your Terraform configuration. This step downloads the necessary providers.

terraform init

3.       Plan the Configuration: Create an execution plan, which lets you preview the changes that Terraform will make to your infrastructure.

terraform plan

4.       Apply the Configuration: Apply the configuration to create the EC2 instance.

terraform apply

5.       Confirm Apply: When prompted, type yes to confirm the apply step.

 

After testing, if you want to delete the created resources, you can use:

terraform destroy

This will remove all the resources defined in your Terraform configuration.

This basic setup gets you started with Terraform and AWS EC2 instances. You can expand and customize it as needed for your specific requirements.

Multiple instances

# Define the EC2 instance resource

resource "aws_instance" "example" {

  count         = 5

  ami           = "ami-0862be96e41dcbf74"

  instance_type = "t2.micro"

 

  tags = {

    Name = "ExampleInstance-${count.index}"

  }

}

TERRAFORM

Terraform is an open-source infrastructure as code (IaC) tool developed by HashiCorp. It allows you to define and provision data center infrastructure using a high-level configuration language known as HashiCorp Configuration Language (HCL), or optionally JSON. Terraform is designed to create, manage, and update infrastructure resources such as virtual machines, networks, and storage in a reproducible and automated manner.

WHY USE TERRAFORM:

1. Infrastructure as Code (IaC):
• Terraform enables you to write code to define and manage your infrastructure. This code can be versioned, reviewed, and shared, making your infrastructure setup transparent and consistent.
2. Declarative Configuration:
• You declare the desired state of your infrastructure, and Terraform takes care of the rest. For example, if you need an AWS EC2 instance, you specify it in the configuration, and Terraform ensures it is created as described.
3. Resource Management:
• Terraform manages the lifecycle of infrastructure resources. This includes creating, updating, and deleting resources as specified in the configuration files.
4. Execution Plans:
• Before applying changes, Terraform generates an execution plan that shows what actions will be taken to reach the desired state. This helps in understanding and validating the changes before they are applied.
5. State Management:
• Terraform keeps track of the state of your infrastructure using a state file. This file is used to map your configuration to the real-world resources, ensuring consistency and enabling Terraform to determine what changes need to be made.
6. Provisioning Across Multiple Providers:
• Terraform supports a wide range of cloud providers and services, including AWS, Azure, Google Cloud, Kubernetes, and many others. This allows you to manage infrastructure across multiple platforms using a single tool.

7.      Standardize configurations

Terraform supports reusable configuration components called modules that define configurable collections of infrastructure, saving time and encouraging best practices. You can use publicly available modules from the Terraform Registry, or write your own.

The core Terraform workflow consists of three stages:

·        Terraform Init

            Terraform init is the command used to initialize a Terraform working directory. This command              sets up the environment and prepares it for further actions.

·         Plan: Terraform creates an execution plan describing the infrastructure it will create, update, or destroy based on the existing infrastructure and your configuration.

·         Apply: On approval, Terraform performs the proposed operations in the correct order, respecting any resource dependencies. For example, if you update the properties of a VPC and change the number of virtual machines in that VPC, Terraform will recreate the VPC before scaling the virtual machines.

UNDERSTANDING TERRAFORM

Imagine You are Building a House

1. Blueprints (Terraform Configuration Files):
• Just like you need blueprints to build a house, you use Terraform to write down the plans for your infrastructure. This plan includes all the details about what your infrastructure should look like, such as the number of servers (like rooms), databases (like plumbing), and networking settings (like electrical wiring).
2. The Builder (Terraform Tool):
• Terraform is like a smart builder who reads your blueprints and constructs the house exactly as you've planned. It takes care of all the details and makes sure everything is put together correctly.
3. Step-by-Step Plan (Execution Plan):
• Before the builder starts working, they show you a detailed plan of what they will do. This is Terraform’s "execution plan," which tells you what changes it will make to your infrastructure.
4. Construction (Applying Changes):
• Once you approve the plan, the builder starts constructing your house. Similarly, when you run terraform apply, Terraform creates or updates your infrastructure based on the blueprint.
5. State of the House (State Management):
• Terraform keeps track of the current state of your house. If you want to make changes later, it knows exactly what the house looks like now and what needs to be changed to match the new blueprints.
6. Multiple Builders (Providers):
• Terraform can work with many different builders (cloud providers) like AWS, Google Cloud, and Azure. It can build parts of your house (infrastructure) in different places using the same set of blueprints.

7.     Understanding Modules

In Terraform, modules are like reusable blueprints or building blocks. Instead of writing the same detailed plan for every house you build, you can create a module once and reuse it whenever you need to build that part of the house.

 

MONOLITHIC VRS MICROSERVICE

THE LEGANCY MONOLOTHIC

A monolithic application is a software design pattern where all components of the application are interconnected and interdependent, forming a single unified unit. Here's a detailed breakdown of what a monolithic application entails:

Characteristics of Monolithic Applications

o   All functionalities of the application are contained within a single codebase.

o   This includes the user interface, business logic, and data access layers.

o   The different modules and components of the application are tightly integrated.

o   Any changes in one part of the application can potentially impact other parts, making it difficult to modify or update the system incrementally.

Disadvantages of Monolithic Applications

1. Flexibility:
• Hard to adopt new technologies or frameworks incrementally.
• Making changes or updates can be risky and time-consuming because of the tight coupling between components.
2. Deployment Complexity:
• The entire application must be redeployed even for small changes, which can lead to longer downtimes and increased risk of introducing bugs.
3. Maintenance Challenges:
• As the codebase grows, it becomes more complex and harder to manage.
• Technical debt can accumulate quickly, making it harder to introduce new features or fix bugs.

 

What is a Monolithic Application?

Think of a monolithic application as a single, large restaurant kitchen where all the chefs work together in the same space to prepare every dish on the menu.

How it Works

1. All-in-One Kitchen:
• The entire kitchen is one big room where all the cooking happens.
• In our restaurant, this means the appetizers, main courses, desserts, and drinks are all prepared in the same kitchen, using the same equipment and space.
2. Tightly Connected Chefs:
• All the chefs work closely together. If one chef needs to make a change, like using a different ingredient, they have to coordinate with everyone else in the kitchen.
• This is like having all the cooking stations (grill, oven, prep area) in one big room. If one station changes, it can affect the others.
3. Single Kitchen Operation:
• When the restaurant needs to update the menu or fix something in the kitchen, they have to update or fix the entire kitchen.
• Think of it like having to close the entire kitchen for renovations, even if only one part of it needs updating.

Disadvantages

1. Hard to Scale:
• If the restaurant gets busier and needs to serve more customers, scaling up the kitchen can be difficult because you can't just add more chefs without reorganizing the entire kitchen.
• It’s like trying to fit more chefs into the same space without adding more kitchen areas, leading to overcrowding.
2. Difficult to Update:
• Making changes to the menu or fixing kitchen equipment can be risky and complicated because everything is so interconnected.
• This is like needing to close the entire kitchen for any update or repair, which can disrupt the whole restaurant.
3. Downtime:
• Every time there's a major update or repair needed, the entire kitchen has to close, leading to more downtime.
• It's like having to stop all cooking in the restaurant to fix or update one part of the kitchen.

When It's a Good Fit

A monolithic kitchen is great for smaller restaurants or when you're just starting out because it's simpler to manage and oversee. However, as the restaurant grows and the menu expands, it can become harder to manage efficiently and may require a different approach, like dividing the kitchen into specialized areas.

In summary, a monolithic application is like a single, large kitchen where everything is prepared and managed together. It's easy to start with but can be challenging to maintain and scale as the restaurant (or application) grows. For larger, more complex systems, a microservices architecture might be more suitable, as it allows for independent scaling, deployment, and management of different components.

 

 THE MODERN MICROSERVICE

What is a Microservice?

A microservice is a software design pattern where an application is composed of small, independent services that work together. Each service handles a specific piece of the application's functionality and can be developed, deployed, and scaled independently.

Characteristics of Microservices

1. Independence:
• Each microservice operates independently and focuses on a specific task or business function, such as user authentication, payment processing, or inventory management.
2. Decoupled:
• Microservices are loosely coupled, meaning changes to one service usually don’t affect the others.
3. Small and Focused:
• Microservices are small and manage a single piece of functionality, making them easier to understand and manage.

Advantages of Microservices

1. Scalability:
• Each microservice can be scaled independently. If one part of the application needs more resources, only that service needs to be scaled up.
2. Flexibility:
• Different microservices can use different technologies, languages, and databases best suited for their specific tasks.
3. Resilience:
• If one microservice fails, it doesn’t necessarily bring down the entire application. The other services can continue to operate.
4. Faster Development:
• Teams can develop, test, and deploy microservices independently, speeding up the development process and making continuous deployment easier.

When to Use Microservices

• Large, Complex Applications:
• Ideal for large applications with many different functions that need to be developed and maintained by separate teams.
• Continuous Deployment:
• When you need to deploy updates frequently and independently without affecting the whole application.

What is a Microservice?

Think of your application as a music band, and each musician in the band represents a different part of the application. In a microservice architecture, each musician (microservice) plays their own instrument and can perform independently, but together they create a complete performance.

How it Works

1. Individual Musicians:
• Each musician in the band plays a specific instrument: one plays the guitar, another plays the drums, and another plays the keyboard.
• In your application, one microservice might handle user login, another might handle payments, and another might manage product inventory.
2. Independent but Coordinated:
• Each musician can practice and improve their part independently, but they coordinate to play music together.
• Each microservice can be developed, deployed, and scaled independently, but they communicate and work together to form the complete application.
3. Communication:
• The musicians use sheet music or signals to stay in sync with each other.
• Microservices communicate with each other through APIs (like sending messages or signals).

Advantages of Microservices

1. Scalability:
• If the band becomes popular, you can add more guitarists or drummers without needing to change the whole band.
• In your application, if one service needs more resources (like handling more users), you can scale up just that service.
2. Flexibility:
• Each musician can use their own instrument and techniques that are best suited for their part of the performance.
• Different microservices can use different technologies that are best suited for their specific tasks.
3. Resilience:
• If the drummer can't make it to the performance, the rest of the band can still play, albeit with some adjustments.
• If one microservice fails, the others can keep running.
4. Faster Development:
• Each musician can practice their part separately, making it quicker to learn new songs.
• Development teams can work on different microservices independently, speeding up the overall development process.

When to Use Microservices

• Large, Complex Projects:
• If your application is big and has many different features, breaking it into smaller, manageable pieces can be very helpful.
• High Scalability Needs:
• If different parts of your application need to handle different amounts of work, microservices allow you to scale them independently.
• Frequent Updates:
• If you need to update parts of your application often, microservices make it easier to update one part without affecting the others.

Conclusion

A microservice architecture is like a music band where each musician plays their own instrument independently, but together they create beautiful music. This makes it easier to manage, update, and scale different parts of the application separately. While it can be more complex to manage, the benefits often make it worth it for large and complex applications.

 Container Orchestrators

With enterprises containerizing their applications and moving them to the cloud, there is a growing demand for container orchestration solutions. While there are many solutions available, some are mere re-distributions of well-established container orchestration tools, enriched with features and, sometimes, with certain limitations in flexibility.

• Kubernetes
  Kubernetes is an open source orchestration tool, originally started by Google, today part of the Cloud Native Computing Foundation (CNCF) project.

 

Where to Deploy Container Orchestrators?

·        Most container orchestrators can be deployed on the infrastructure of our choice - on bare metal, Virtual Machines, on-premises, on public and hybrid clouds.

·        In addition, there are cloud solutions which allow production Kubernetes clusters to be installed, with only a few commands, on top of cloud Infrastructures-as-a-Service. These solutions paved the way for the managed container orchestration as-a-Service, more specifically the managed Kubernetes as-a-Service (KaaS) solution, offered and hosted by the major cloud providers. Examples of KaaS solutions are Amazon Elastic Kubernetes Service (Amazon EKS), Azure Kubernetes Service (AKS), DigitalOcean Kubernetes, Google Kubernetes Engine (GKE), IBM Cloud Kubernetes Service, Oracle Container Engine for Kubernetes