Amazon EC2 - Creating an AWS EC2 Instance

AWS EC2 Key Concepts

Key Concepts

Virtual Machine (VM)

• Computer resources implemented as software rather than on dedicated hardware devices

Instance

• A VM running on the AWS cloud

Amazon Machine Image (AMI)

• A template containing the software configuration (operating system, application server, and applications) required to launch an instance

Instance Type

• Various configurations of CPU, memory, storage, and networking capacity for instances

Amazon Elastic Block Store (EBS)

• Persistent storage volumes for use with Amazon EC2 instances

Instance Store

• Temporary storage that's physically attached to the host computer for an instance

Amazon Virtual Private Cloud (VPC)

• A virtual network dedicated to your AWS account

Region

• A geographical area where AWS infrastructure is located

Availability Zone

• One or more discrete data centers with redundant power, networking, and connectivity in an AWS Region

VM Image

• A file containing the state information of a virtual machine

Security Group

• A service that controls/regulates network access like a firewall

Secure Shell (SSH)

• An application or protocol for logging into another computer over a network or executing commands on a remote system

Key Pair

• A pair of keys consisting of a public key and private key based on RSA algorithm, used to access VM instances

Amazon EC2 Basics

• With Amazon EC2 (Elastic Compute Cloud) infrastructure, you can run server instances that execute AMI (Amazon Machine Images)

• The range of available instance types is very broad depending on memory, processing power, and local disk storage

• Each instance is protected by a firewall, which blocks all internal/external connections

  • When launching an instance, you can configure multiple security groups to the instance, and use security groups to control access to the instance!

• When an instance is launched, the EC2 infrastructure provides the instance with an IP address and DNS entry!

  • However, the IP address and DNS entry are temporary!

    • When an instance shuts down, the IP address and DNS entry assigned to the instance are released

  • In such cases, if you need an IP address that continues to be maintained even after shutdown or can be mapped to one of many machines, you can use an Elastic IP address!

    • This address is effectively owned by the AWS account, not by a specific EC2 instance

      • So once allocated, it becomes yours until you release it!

Creating an EC2 Instance

1. Region Configuration

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• When running a server in Korea, Asia Pacific (Seoul) is the fastest with the shortest latency, so choose ap-northeast-2

2. AMI (Amazon Machine Image) Selection

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• There are many diverse Images to choose from as AMI

• If you have a separate server for the app you want to deploy or have a preferred distro, select that Image

  • I love Ubuntu, so I selected Ubuntu Server 18.04 LTS (HVM)

3. Instance Type Selection

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• Select the instance type that matches the required performance

• Of course, the higher the performance, the higher the price

• For practice purposes, I selected t2.micro which can be used with the free tier

4. Instance Details Configuration

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• When creating an EC2 instance, VPC is automatically created

  • VPC Summary

5. Add Storage

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• I used the default settings

6. Add Tags

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• What is a Tag?

  • It means a key and value pair that users specify to make AWS resource management convenient

  • Can be removed from resources at any time

  • In IAM, you can set users who can control (edit, create, delete) tags

7. Security Group Configuration

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• What is a Security Group?

  • It allows detailed control of EC2's inbound and outbound traffic

• Enter the security group name and description

  • I added a description that this is a security group that allows default SSH port (22) and port 80

8. Review

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9. Key Pair Creation

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• A key pair is necessary to access the instance remotely

• Click Create a new key pair, write the key pair name, and click Download Key Pair

• Remember that once a key pair is issued, there is no way to get it again, so you must keep it safe!

10. Connecting After Instance Creation

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• When you click Connect in the AWS Console, you'll see the screen above - just follow the instructions!

10-1. Navigate to Where the PEM Key is Stored

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10-2. Grant User Read Permission

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• The chmod command is used to change access permissions (file mode) for files or directories

• chmod 400 gives only read permission to the User and removes read permission from everyone else

• Meaning of Each Digit

  • First digit means User

  • Second digit means Group

  • Third digit means Other

• Meaning of Numbers

  • 4 means Read permission

  • 2 means Write permission

  • 1 means Execute permission

10-3. Connect via SSH

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• What is SSH?

  SSH stands for Secure Shell Protocol, which is one of the Network Protocols used to communicate securely when computers communicate with each other through public networks like the internet

• Use the format SSH -i [user account] [server address]

EC2 creation and connection complete!

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EC2 Configuration Related Tips

1. Burstable instances

• Amazon burstable instances provide burst functionality that increases performance as needed for momentary CPU loads

• Supported instance families are T2, T3, and T4

  • T3 and T4 default to Unlimited,

  • T2 defaults to Standard