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EC2 Basics

EC2 is one of the most popular AWS offerings. It stands for Elastic Compute Cloud (ECC -> EC2) and it's an Infrastructure as a Service (IaaS) offering.

Key takeaways​

  • As an IaaS, we aren't just getting a platform, we are renting the raw virtual hardware.
    • Main Components:
      • Instances: The Virtual Machines (VMs) themselves.
      • EBS Volume: Virtual drives for our data.
      • Elastic Load Balancer (ELB): Spread the traffic so one machine doesn't get overwhelmed.
      • Auto Scaling Group (ASG): Automatically adds or removes machines based on how much traffic we have.
  • EC2 sizing & configuration options:
    • OS: Linux (most popular), Windows or even macOS.
    • Power: How many CPU cores and how much RAM we need.
    • Storage: Network-attached (EBS/EFS) or straight-up hardware-attached (Instance Store).
    • Network: Choosing our speed and public IP.
    • Firewall rules: Setting up security groups to control who can talk to our instances.
    • Bootstrap script: to configure the instance at first launch.
  • The Bootstrap (EC2 User Data):
    • What it is: A script that runs only once the very first time the instance boots up.
    • Use cases: EC2 User Data is used to automate boot tasks such as:
      • Installing updates
      • Grabbing software from remote repositories
      • Downloading files from the internet
    • Permissions: The script runs as the root user, so it has full sudo power by default.
    • Trade off: Be mindful, the more stuff we put in the script, the longer it takes for the instance to become "Running".