Amazon EC2 (Elastic compute cloud ☁🖥) -Zero to Hero🚀🚀 (Cheat Sheet)

#aws #cloud #serverless #beginners

In this series I am going to share multiple articles that will teach you from basic to advanced about EC2. So Lets start !!!

What is EC2 ?

EC2 is a web service that provides resizable compute capacity in the cloud.
It is designed to make web-scale cloud computing easier for developers.
Most popular and most used AWS offering.
EC2 = Elastic Compute Cloud = Infrastructure as a service(IaaS)
- It mainly consists of: – Renting Virtual machines(EC2)
- Storing data on Virtual drives(EBS)
- Distributing load across machines(ELB)
- Scaling the services using an auto-scaling group(ASG)
In this you pay only for capacity that you actually use.
EC2 Provides developers the tools to build failure resilient applications and isolate themselves from common failure scenarios.

Below are some features of EC2:

1. Reliability

EC2 provides 99.9% availability in each region. The services are highly reliable, where replacement of instances can be done easily and rapidly.

2. Cost Saving

EC2 is inexpensive as it allows the user to select plans as per the requirement. It helps the users to save cost and utilize the resources fully.
User's also get benefits from the AWS scale, which enables the users to pay less for virtual servers than other cloud providers.
EC2 works on pay-as-you go model and as a customer we only pay for the time we use EC2.
With the use of EC2, we can eliminate the need to invest upfront cost on Capex for hardware (servers).

3. Elasticity

Companies can easily increase or decrease capacity within minutes. They can also provision thousands of server instances simultaneously.
Apart from that, all the server instances are handled by web service APIs that can scale up and down the servers as per the requirements.

4. Scalability

In EC2 we can scale-in and scale-out depending on load. It also provides autoscaling capabilities
Auto-scaling is the capability built into AWS that allows you to ensure you have the right number of EC2 instances provisioned to handle the load of your application.
We can use EC2 to launch as many virtual machines as per our needs.
It provides scalable computing capacity in AWS cloud.
It also helps in building application with redundancy and resilience.

5. Security

AWS works with Amazon VPC to provide robust networking and security for the compute resources.
All the compute instances are located in a VPC (Virtual Private cloud) in a specific range. This specific functions help the user in deciding which instances are exposed to the internet and which remains private

We can choose from various options in EC2 like below:

Operating System(OS): Linux, Windows or macOS
Compute power, processors and cores(CPU)
Random-access memory(RAM)
Storage space:
- Hardware(EC2 Instance Store)
- Network-attached storage(EBS & EFS)
Firewall Rules: Security group
Network card: speed of the card, Public IP address

We can bootstrap our instances using an EC2 User data script.
Bootstrapping means launching commands when a machine starts
This script only run once when the instance start.
Usecase of EC2 user data is to automate boot tasks such as:
- Installing updates
- Installing softwares
- Downloading common files from the internet
- A lot more
The EC2 user data script runs with the root user

Security groups(SG) are the fundamentals of network security in AWS.
SG controls, how the traffic is allowed into or out of our instances.
SG only contain allow rules
SG rules can reference by IP or by security group.
Security groups acts as a "firewall" for EC2 instances.
Security groups regulates :
- Authorized IP ranges -IPv4 and Ipv6
- Access to ports (like SSH, HTTP and HTTPS)
- Control of inbound network(from other to the instance)
- Control of outbound Network(from instance to other)