launching an ec2 instance

These are some general notes from launching an EC2 instance. This demo from acloudguru.com has us configuring an EC2 instance as a web server.

General notes

• Amazon Machine Image (AMI) - The software configuration (OS, application server, and apps) required to launch the instance.
  • These images might be preconfigured for things like machine learning or databases
• Spot instances are at different price tiers and availability zones, but have reduced cost

Example spot instance pricing:

Startup scripts

• The user data section of the "advanced details" on EC2 creation allows for bootstrap scripts
  • These are scripts/commands we want run when the instance is started
  • Example: Update our operating system packages on startup

Storage volumes

• For storage we can choose to add new volumes and file systems for our EC2 instance
  • Storage can be encrypted using KMS (key manage service) and it is very easy to manage

Tagging instances

• Tags are a way to organize instances with key-value pairs for naming, team ownership, or apps

Security

• Security groups are the firewalls that we have for our EC2. This is for access control
  • By default we have SSH on port 22
  • Adding a new HTTP rule for port 80 with a source of "anywhere" is what a webserver would need
    • IPV4 notation: 0.0.0.0/0
    • IPV6 notation: ::/0

SSH into the EC2

• On creation we have to create a key pair, and are given a .pem file
  • This needs to be stored in a secure location and shared sparingly
  • Keys need to have their permissions set, using chmod 400 <key name>

Changing our permissions of the .pem file:

chmod 400 <key name>.pem

To SSH into our server:

ssh ec2-user@<public IP> -i <key name>.pem

# continue?
> yes

Updating the EC2

We can do this as root, or as our ec2-user.

# -y for "yes"
yum update -y

Starting an Apache webserver at boottime

Creating an Apache webserver instance on startup of the EC2 instance will turn this into a tiny webserver.

# install Apache webserver
yum install httpd -y

# starts service
systemctl start httpd

# enable the service on startup
systemctl enable httpd

# check the status
systemctl status httpd