Things to do after creating an EC2 instance and connecting to it using SSH

Source: Dev.to

🧭 Big Picture First

At this point, you’ve already:

• Created an EC2 instance
• Connected to it via SSH

Now you’re inside the server. Before installing anything or making changes, you need to understand what you’re running.

🧱 Phase 1 — Identify the System

1️⃣ Check the OS & Kernel

uname -a

Purpose

• Identify OS type, kernel version, architecture, and environment (AWS)

Why it matters

• Determines which tools you use (dnf, systemctl)
• Avoids wrong commands (e.g., apt on Amazon Linux)

📦 Phase 2 — Package Management Basics

2️⃣ Update system packages

sudo dnf update

Purpose

• Bring all installed software up to date
• Apply security patches

Why it matters

• Security
• Stability
• Best practice on new servers

3️⃣ Query installed kernel

rpm -q kernel

Purpose

• Check kernel version via the package database

Why it matters

• Kernel is installed like any other package
• Helps during upgrades & debugging

4️⃣ Install nginx

sudo dnf install nginx

Purpose

• Download and install nginx from trusted repositories

Why it matters

• Demonstrates proper software installation
• Dependency resolution happens automatically

5️⃣ Verify nginx is installed

rpm -q nginx

Purpose

• Confirm nginx exists at the RPM level

Why it matters

• Installation ≠ running
• Always verify installs

⚙️ Phase 3 — Service Management (systemd)

6️⃣ Check nginx service status

sudo systemctl status nginx

Purpose

• Show whether nginx is running, plus logs, PID, uptime, and config validation

Why it matters

• Services must be monitored, not assumed

7️⃣ Start nginx (if needed)

sudo systemctl start nginx

Purpose

• Start the nginx service

Why it matters

• Installed services don’t auto‑run

🌐 Phase 4 — Verify Functionality

8️⃣ Test locally

curl localhost

Purpose

• Verify nginx responds internally

Why it matters

• Separates Linux issues from AWS networking issues

9️⃣ Open port 80 in AWS

Action

• In the Security Group, allow HTTP (port 80)

Purpose

• Allow external traffic

Why it matters

• AWS firewall blocks traffic by default

📁 Phase 5 — Understand Configuration Safely

🔟 View nginx config safely

sudo less /etc/nginx/nginx.conf

Purpose

• Read the main nginx configuration (read‑only)

Why it matters

• Understand before modifying
• Avoid breaking production configs

🧠 Key Concepts You’ve Learned

• Linux kernel vs. OS
• Package managers (dnf, rpm)
• Installed vs. running software
• systemd & services
• Safe config inspection
• Zero‑downtime reloads
• Cloud networking basics
• Production hygiene

🧩 Mental Model (Very Important)

EC2 instance
 ├── Linux OS
 │    ├── kernel (rpm)
 │    ├── packages (dnf)
 │    └── services (systemctl)
 │
 ├── nginx installed (rpm)
 ├── nginx running (systemd)
 ├── nginx configured (/etc/nginx)
 └── traffic allowed (AWS SG)

🎯 Where You Are Now

You can now operate and reason about a Linux service on the cloud. This foundation supports further learning in:

• Docker
• Kubernetes
• CI/CD
• SRE
• Platform engineering