I’m currently studying DevOps Beginners to Advanced with Projects on Udemy. Here are some notes on using AWS:

Creating an EC2 Instance

The most basic computing unit:

• Name and Tag
  • Here, you can choose to “add additional tags” to provide extra labels for easy identification on the AWS console.
• AMI (Amazon Machine Image)
  • An AMI is like an image, similar to running a Docker image to create a container, but here, you create an EC2 instance.
• Instance Type
  • For the free tier, I’ve only used t2.micro. In real scenarios, you can choose different resource levels based on your requirements.
• Key Pair
  • AWS uses SSH keys for remote access. Choose the key pair for this instance. You can reuse a key pair across different instances for better key pair management.
• Network Settings
  • Configure inbound and outbound rules. Typically, you’d open inbound for SSH and add “my IP” as the source. For web services, you’d add HTTP with a source of “anywhere.”
• Configure Storage
  • AWS offers various storage types, such as SSD, HDD, and specialized types based on I/O.
• Advanced
  • Here, I used the “User Data” field. You can write shell scripts in this field to install software or complete specific configurations during instance launch.

Elastic Block Store (EBS)

Storage options:

• Volume Type
  • You can choose storage types like SSD, HDD, or specialized types based on I/O.
  • You can also select the region for volume creation.
• AWS allows dynamic attachment of volumes to instances.
  • Use fdisk -l to check the volume’s name.
  • Use fdisk /dev/xvdf to create partitions. The path might vary based on the previous command’s output.
    • m for help
    • n new partition
    • p primary
    • partition number: default
    • First sector: default
    • Last sector: default
    • w write table to disk
  • Create partitions, format them using mkfs.ext4, and check with lsblk.
  • Mount the partition using mount /dev/xvdf1 {target path}. To make it auto-mount, modify /etc/fstab.
• Snapshot
  • Important data, like a database, is often stored on a separate volume.
  • You can use EBS snapshots to back up a volume and later restore it by creating a new volume from the snapshot.

Load Balancing

An example with two instances running the same HTTP server:

• Create a Target Group
  • Configure health checks to ensure instance health. For a web server, set up periodic HTTP requests to a specific path.
  • Add instances to the target group.
• Create a Load Balancer
  • For example, use an Application Load Balancer.
  • Configure security groups for inbound HTTP traffic.
  • Set up listeners & routing to forward traffic to the target group.
• Adjust the security group of the target group to allow access from the load balancer’s security group.

CloudWatch

Create alarms, such as monitoring CPU resources:

• Go to “All Alarms” and create a new alarm.
• Select metrics, e.g., EC2, per-instance metrics.
• Choose the instance ID and select CPUUtilization.
• Set the threshold (e.g., 60%) and configure notification details for email or groups.

Amazon Elastic File System (EFS)

Similar to NFS on Linux, suitable for shared storage among multiple instances:

• Create a security group for EFS.
  • Create an EFS file system with default performance settings or adjust as needed.
  • Configure network settings with the security group for all availability zones.
• Create an access point.
  • Mount EFS from an EC2 instance using the amazon-efs-utils. sudo yum install -y amazon-efs-utils. official doc
  • Update /etc/fstab
    • Add {file-system-id}:/ {efs-mount-point} efs _netdev,noresvport,tls,accesspoint={access-point-id} 0 0
    • official doc
  • execute mount -fav.
  • If you see {mount-point}: successfully mounted, you’re done.