⚡ How SSL Certificates Work? | HTTPS Explained with Hands-On Demo

🎯 Why SSL & HTTPS Matter
Every DevOps engineer eventually faces this:
The server is up, Nginx is running fine, but users can’t reach the site — because the SSL certificate expired.

Instead of your app, they see a scary red “Your connection is not private” page. Traffic drops to zero instantly.

Knowing how SSL really works — and how to test it locally — separates engineers who just restart services from those who can prevent real outages.

▶️ What You’ll Learn in This Video
In this step-by-step hands-on demo, I break down: https://youtu.be/AJ7owDXl9_8

📌 Basics of SSL & HTTPS

• Why HTTP shows Not Secure

• What SSL certificates do

• Self-signed vs trusted certificates

📌 Hands-On Setup

• Generating a certificate with OpenSSL

• Configuring Nginx for HTTPS

• Debugging with curl -vk

📌 Going Further

• Creating your own local Certificate Authority (CA)

• Trusting your CA in Ubuntu + Chrome

• Reloading browser to see the 🔒 lock locally

👉 Watch the full video here: [YouTube Link]
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🛠 Takeaway Example Command
❓ How do you generate a one-year self-signed certificate?

✅ Answer:

openssl req -x509 -nodes -newkey rsa:2048 \
  -keyout valid.key \
  -out valid.crt \
  -subj "/CN=learnwithdevopsengineer" \
  -days 365 \
  -addext "subjectAltName=DNS:learnwithdevopsengineer"

💡 This not only creates a key and cert, but also sets the SAN correctly — something interviewers love to ask about because missing SAN is a real-world cause of SSL failures.

💡 Why This Guide Stands Out

• Real-world focus → I don’t just explain SSL, I simulate the red screen outage.

• Practical → from HTTP → HTTPS → trusted CA, all tested in Nginx.

• Debug-driven → you’ll see how curl and browser tools confirm what’s really happening.

This isn’t theory — it’s production-grade troubleshooting explained step by step.

👋 Final Note
If you enjoyed this breakdown, hit subscribe to my newsletter.
Every week I share real DevOps outages, interview prep, and hands-on labs you can reproduce — so you’ll never be caught off guard in production.

— Arbaz
📺 YouTube: Learn with DevOps Engineer
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