#AWS  #EC2  #DevOps 

Amazon EC2

What is EC2

  • Amazon Elastic Compute Cloud
  • Deployment of servers
  • Amazon EC2 is a web service that provides resizable compute capacity in the cloud.
  • Highly scalable & pay-as-you-go model
  • EC2 is not a Global service, it is specific to a Region

Amazon Machine Image (AMI)

  • An AMI is a template that contains the software configuration (OS, application server, and applications) required to launch your instance
  • Select any OS you want
    • Windows 10, Ububtu 16, Mac etc
  • Preconfigured AMIs
    • You can select it from AWS marketplace

Amazon EC2 Instance Types

  • Instance Types are based on CPU, RAM, Storage, Networking capacity
  • General purpose
    • Provide a balance of compute, memory and networking resources
    • Series: T(t2, t3), A(a1), M(m4, m5)
  • Compute optimized
    • Provides high performance processors
    • Series: C(c4, c5)
  • Memory optimized
    • Memory optimized instances to process large data sets in memory
    • Series: R, X
  • Accelerated Computing
    • Used for high performance computing(Machine learning, speech recognition)
    • series: P, G, F
  • Storage optimized
    • Used for high sequential read and write access to very large data sets on local storage
    • Series: I, D, H

AWS Nitro System

  • AWS own virtualization system
  • Traditionally hypervisors is used but now Nitro system is used.
  • Its a next generation of EC2 instances that enables AWS to innovate faster, further reduce cost for our customers, and deliver added benefits like increased security and new instance types.

Launch a EC2 Instance

  1. Add Name & Tags
  2. Select AMI
  3. Select Instance Type
  4. Select old key-pair or create new
    • Download the key-value pair(name.pem)
    • NOTE: It’s only way to get into the EC2 machine
  5. Network Setting
  6. Configure storage
  7. Advanced detail

Connect to EC2 instance

  • Select EC2 > Action > Connect
  • Can connect in two ways
    1. EC2 Instance Connect
      • Directly connect from browser
    2. SSH Client
      • Use this name.pem to connect the instance
      • chmod 400 name.pem
        • For macOS or Linux, set the permissions of your private key file.
        • Gives the user read permission, and removes all other permission.
      • sudo ssh -i "name.pem" ubuntu@Public-IPv4-DNS or
      • sudo ssh -i "name.pem" ubuntu@Public-IPv4-address
    • Connected by CLI, ready to start configuration

Update Security Group

  • EC2 > Instance > Instance ID > Security > Security groups
  • Currently only SSH(port-22) is inbound rules
  • Now need to Enable web-trafic to come
    • Inbound rules > Edit inbound rules > Add rule HTTP TCP 80 Anywhere (Can enable for both IPv4 and IPv6)

Configure/Launch an AWS webserver

Create a small webserber(website) to test EC2 connection

1. Enable HTTP 80(shown above)

2. Install webserver

# Install httpd

sudo yum update -y
sudo yum install httpd -y
sudo systemctl start httpd
systemctl status httpd

# httpd restarts after system restarts
systemctl enable httpd

# Install Apache2
sudo apt update -y
sudo apt install apache2 -y

sudo systemctl status apache2

3. Create html file

cd /var/www/html/

# Get root permision
sudo su

# Add some html
vim index.html

4. Visit

* public_ip
* public_ip:80
* public dns

Delete EC2

  • Select EC2 > Instance state > Terminate instance
  • Terminate the instance
    • All the volume will be delete
  • Status will be updated to ‘terminated’
  • In some time instance will be removed

Copy data from remote to local and vice-versa

  • Copy from remote to local
    • scp -i "name.pem" [email protected]:~/file1 ~/Downloads/
    • Download file1 from EC2 to local Downloads folder
  • Copy from local to remote
    • scp -i "name.pem" ~/Downloads/random.json [email protected]:~/
    • Copy ramdon.json from local to EC2

Stress Testing & Monitoring

Create EC2 instance Alarm

  • Select EC2 > Action > Monitor and troubleshoot > Manage CloudWatch alarms
  • Can add alarm notification or take action on
    • CPU utilization
    • Status check etc…
  • Can install stress package to test above

AWS Cloudwatch Alarm Setup

Enable the EPEL repository

# Installation
sudo amazon-linux-extras install epel -y
sudo yum install stress -y

# Test - Apply stress
stress --help
stress --cpu 7

User data

  • When you launch a Windows instance in Amazon EC2, you can pass user data to the instance
  • It can be used to perform automated configuration tasks or to run scripts after the instance starts.
  • It runs only once as root when the instance is created
#!/bin/bash

yum update -y
yum install httpd -y
systemctl start httpd
systemctl enable httpd

cd /var/www/html

echo "<h1> This is Machine-1</h1>" > index.html
  • Visit Public IPv4 address:80

Instance metadata

  • Instance metadata is data about your instance that you can use to configure or manage the running instance.
  • These are sensetive-data and can only access within the instance itself.
# Retrieve instance metadata
curl http://169.254.169.254/latest/meta-data

curl http://169.254.169.254/latest/meta-data/hostname
curl http://169.254.169.254/latest/meta-data/public-ipv4

Elastic IP

  • An Elastic IP address is static, it does not change over time
    • Generally when we restart an instance IP get automatically changed.
  • Designed for dynamic cloud computing and is yours until you release it.
  • Elastic IP is allocated based on region
  • Create Elastic IP
    • EC2 Dashboard > Network & Security > Elastic IPs > Allocate Elastic IP address > Select region > Allocate
  • Assing IP to EC2
    • Select Elastic IP > Action > Associate Elastic IP address > Select instance > Slect private ip(not req) > Associate
  • Associate and Delete
    • Select Elastic IP > Action > Deassociate Elastic IP address
    • Select Elastic IP > Action > Release Elastic IP address

Elastic IP address pricing

  • Small hourly charge if an Elastic IP address is
    • not associated with a running instance,
    • associated with a stopped instance or
    • associated with an unattached network interface.
  • No charged if associated running instance.

Network Interface

  • An elastic network interface is a logical networking component in a VPC that represents a virtual network card
  • Create network interface
    • EC2 Dashboard > Network & Security > Network Interfaces > Create network interface
    • Select subnet –> specific your EC2
    • IPV4 –> Auto-assign
  • Flow log
    • Flow logs can capture IP traffic(In and Out traffic) flow information for the network interfaces associated with your resources
    • Will not get this info in Cloudwatch

Create Custom AMI

  • Amazon Machine Images (AMIs)
  • A custom AMI can bu useful when you need to install a lot of software that isn’t included in the standard AMIs.
  • We can create custom AMI and can launch AMI instantly with all the software configuration.
  • Create custom AMIs
    • Select EC2 > Action > Image and templates > Create image
  • Get the custom AMI and Launch instance
    • EC2 Dashboard > Images > AMIs > Select AMI > Launch instance from AMI
    • Alt --> EC2 Dashboard > Launch Instance > My AMIs > Select AMI > Launch instance
  • Create Templates
    • Same a custom AMI as above but it also copies configuration
    • Like users data, security groups, permissions etc
  • Delete Custom AMIs
    • EC2 Dashboard > Images > AMIs > Select AMI > Deregister AMI
    • Also delete Snapshot
      • Elastic Block Store > Select > Action Delete Snapshot

Placement groups

  • The EC2 service attempts to place the instance in such a way that all of your instances are spread out across underlying hardware to minimize correlated failures.
  • You can create a placement group using one of the following placement strategies:
    • Cluster – packs instances close together inside an Availability Zone.
    • Partition – spreads your instances across logical partitions
    • Spread – strictly places a small group of instances across distinct underlying hardware to reduce correlated failures.
  • Network & Security > Placement groups
  • It can be selected while launching large instance(say c5.2xlarge)

Reference