EC2

EC2 Features

EC2 provides a web services API for provisioning, managing and deprovisioning virtual servers inside amazon cloud.

Ease In Scaling Up/Down

Pay only for what you are using

Can be integrated into several other services

EC2 Pricing

On Demand: Pay per hour or seconds

Reserved: Reserve Capacity(1 or 3 years) for discounts.

Spot: Bid your price for unused EC2 capacity.

Dedicated Hosts: Physical Server dedicated for you. (not VM)

EC2 Components

Instances: Virtual servers.

AMI: Preconfigured templates for your instances that package the components you need for your server (including the operating system and additional software).

Instance Type: Various configurations of CPU, memory, storage, networking capacity, and graphics hardware for your instances.

EBS volume: Persistent storage volumes for your data using Amazon Elastic Block Store.

Instance store volumes: Storage volumes for temporary data that is deleted when you stop, hibernate, or terminate your instance.

Security groups: A virtual firewall tspecify the protocols, ports, and source IP ranges that can reach your instances, and the destination IP ranges to which your instances can connect.

Key pairs: Secure login information for your instances. AWS stores the public key and you store the private key in a secure place.

Tags: tagging components to make it easier to manage, search and filter.

Creation of EC2 Instance

Chose an AMI --> Chose an instance type --> configure the instance --> adding storage --> adding tags --> configure security group --> REVIEW & PUBLISH

EC2 instance creation order

Requirements Gathering
OS
Size => Ram, CPU, Network etc: https://aws.amazon.com/ec2/instance-types/
Storage size
Firewall & Security Group Rules
Project (Services/Apps Running: SSH, HTTP, Mysql etc)
Enviroment(Dev,QA,Staging,Prod)
Login User/Owner
Create Key-Pairs
Setup Security Groups
Instance Launch

Security Group

A security group acta as a virtual firewall that controls the traffic for one or more instances.

Security groups are "stateful". if inbound rule is updated, then same rule will be updated for outbund.

Inbound rules: Trafic coming from outside in to the instance.

Outbound rules: Trafic going from Instance to outside.

Elastic IP

this is a permanent IP that you can assosiate for your Instance or Network Interface

Elastic Block Storage

Block based storage

Runs ec2 OS, store data from db, file data, etc

Placed in specific AZ. Automatically replicated within the AZ to protect from failure.

Snapshot is a backup of a volume

EBS Types

SSD, IOPS, HDD, COLD HDD, etc...

https://docs.aws.amazon.com/ebs/latest/userguide/ebs-volume-types.html

Snapshot Backup & Restore

Unmount partition
Detach volume
Create new volume from snapshot
Attach the volume created from snapshot
Mount it back

ELB - Elastic Load Balancer

Frontend Ports: Listens from the user requests on this port AKA Listeners. e.g. 80, 443, 25 etc.

Backend Ports: Services running on OS listening on this port. e.g. 80, 443, 8080 etc.

Elastic Load Balancing distributes incoming application or network traffic across multiple targets, such as Amazon EC2 instances, containers and IP addresses, in multiple Availability Zones.

Elastic Load Balancing supports three types of load balancers: - Application Load Balancer - routes traffic based on the advanced application level information that includes the content of the request (https://domain/request). - Network Load Balancer - handles millions of requests per second - Classic Load Balancer - routes traffic based on either application or network level information

more info: https://docs.aws.amazon.com/elasticloadbalancing/

############################ ADMIN AWS TIPS AND TRICKS

Create EBS Volume and mounte to Instance

EC2 > Volumes > Create Volume > Create

select Action on your newly created volume and select Attach volume

select your instance and then type attach

SSH into the VM

sudo -i
fdisk -l
df -h

fdisk /dev/xvdb
Command (m for help): n
Command (m for help): p
Command (m for help): 1
First sector (2048-10485759, default 2048): `Hit enter`
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-10485759, default 10485759): `Hit enter to use all space` or specify how much GB should be allocated to disk e.g. `+3G`
Command (m for help): p
Command (m for help): w

#format partition
mkfs.ext4 /dev/xvdb1

#move files
mkdir /tmp/img-backups
mv /var/www/html/images/* /tmp/img-backups/

mount /dev/xvdb1 /var/www/html/images/
df -h
umount /var/www/html/images
lsof /var/www/html/images #if the command above dosent work | this lists what processes uses the directory so kill those and try again with command above


################################### steps below: will make make the mount persistent, so it will survive reboots

vi /etc/fstab
/dev/xvdb1    /var/www/html/images    ext4 defaults    0 0 #add this line to the file
mount -a
df -h
mv /tmp/img-backups/* /var/www/html/images/
systemctl restart httpd

Create Snapshots in AWS

volumes > Actions > Create Snapshot

SSH in VM:

# make sure to stop any services that are on that volume-directory before umount e.g.:
lsof /var/lib/mysql/
systemctl stop mariadb
umount /var/lib/mysql/
umount -l /var/lib/mysql #remove with force (use with caution)
df -h

detach volume in AWS + rename to corrupted if it is so.

chose your snapshot Action select create volume from snapshot # create image from snapshot is possible if it has a snapshot of "/" root directory

go to volumes and find your newly created volume. click Actions and then Attach volume

SSH in VM:

mount -a
df -h
systemctl start mariadb

Clone Instance to an AMI IMAGE

go to instances > Action > image and templates > create image

in EC2/images/AMIs. your image should be cloned here

quick info: you can copy ami to a different region: AMIs > Action > copy

then create a Launch Template, add AMI to it so you can launch the instance quick.

Load Balancing

go to Target Group > Create Target Group

target type: Instances

port HTTP #or 80

Healthy threshold 2

Unhealthy threshold 2

Timeout 5 seconds

Interval 30 seconds

Sucess codes 200

On next page select 2 instances or more, ports for instances 80 and click on Include as pending below. Create target group

go to Load Balancers > Create Load Balancer

create application load balancer

Scheme: Internet-facing

IP: IPv4

Mappings: Select all zones or 5-10 zones

select or create a security group for your load balancer with port 80 allowed from all IPv4 addresses

Listeners and routing: Protocol HTTP Port 80, select your target your group

Create Load Balancer