AWS EC2 Instances, EBS Volumes & Security Groups

Lab 11 of 20 · EC2 & Firewalls · 5 hands-on activities · bilingual (English + සිංහල)

පිටුව 11: අපේ පළමු Cloud Server එක හදමු - AWS EC2, EBS සහ Security Groups

AWS EC2 Instance වර්ග (t2.medium), Hard disk (EBS) සයිස් කිරීම, සහ Security Group හරහා Port 8080 විවෘත කරන හැටි.

Architectural Foundation & Systems Diagram

AWS EC2 (Elastic Compute Cloud) provides scalable virtual servers in the cloud. You attach virtual disks (EBS) and define stateful virtual firewalls (Security Groups).

• 💻 EC2 Sizing (t2.medium) — For Jenkins and Docker builds, use at least t2.medium (2 vCPUs, 4GB RAM). Micro instances crash under Java JVM build memory pressure.

• 💽 EBS Storage (30GB) — Elastic Block Store (EBS) acts as the virtual SSD. Provision at least 28-30 GB to prevent Jenkins build workspace disk exhaustion.

• 🛡️ Security Groups (Stateful Firewalls) — Virtual firewalls controlling inbound and outbound traffic. You MUST add an Inbound Rule for Custom TCP Port 8080 from 0.0.0.0/0 to access web dashboards!

Step-by-step practical lab

Step 01: Lock Down SSH Private Key Permissions

සිංහලෙන් — SSH Private Key එකේ permissions ආරක්ෂිතව (0400) සකසමු.

Restrict file permissions so only the owner can read the private key, satisfying OpenSSH security requirements.

chmod 400 ~/.ssh/my-key.pem

• 400 : Owner Read Only: අනෙක් කිසිදු පරිශීලකයෙකුට හෝ process එකකට කියවිය නොහැක.

Expected output

-r-------- 1 sre-engineer devops 1675 Sep 16 11:00 ~/.ssh/my-key.pem

Step 02: Test Secure Shell Connection to EC2

සිංහලෙන් — AWS EC2 Server එකකට SSH Key එකක් භාවිතයෙන් සම්බන්ධ වීම.

Connect securely to an AWS EC2 instance via SSH using a private PEM key pair.

ssh -i ~/.ssh/my-key.pem ec2-user@172.31.18.42

• -i : Identity file: Authentication සඳහා භාවිත කරන private key එක දක්වයි.

Expected output

Authenticated with key ~/.ssh/my-key.pem.
Amazon Linux 2023 AMI 2023.4.2026
[ec2-user@ip-172-31-18-42 ~]$

Hands-on practice activities

Work through these yourself — tick them off as you go.

• Activity 51: Check EBS Disk Capacity and Free Space (Drill) — Verify attached EBS volume storage and ensure root partition has over 20GB free space.
• Activity 52: Check Active Listening Web Ports (Drill) — Verify that port 8080 is actively listening on all local interfaces (0.0.0.0:8080).
• Activity 53: Add Security Group Inbound Rule for 8080 (Checkpoint) — In AWS Console: EC2 > Security Groups > Edit Inbound Rules > Add Rule: Type=Custom TCP, Port=8080, Source=0.0.0.0/0.
• Activity 54: Secure SSH Keypair Permissions (Checkpoint) — Execute 'chmod 400 your-key.pem' before attempting SSH connection to your EC2 instance.
• Activity 55: Security Group Stateful Property Quiz (Quiz) — If an inbound packet is permitted by an AWS Security Group, is outbound response traffic automatically allowed? Answer: Yes, Security Groups are stateful.

Keep going: ← Lab 10 · Lab 12 → · Track your progress in the Self Guide