Skip to content

🔥 Types of Rules Every DevOps Engineer Must Know

We’ll keep it vendor-neutral and production-focused.

1️⃣ Redirect Rules

Used to send traffic somewhere else.

Example Use Cases:

  • HTTP → HTTPS
  • Old domain → new domain
  • Force www → non-www
  • Maintenance redirect

Status Codes Used:

  • 301 (Permanent)
  • 302 (Temporary)
  • 307 / 308 (Strict method preservation)

Example Logic:

If host == example.com
→ Redirect to https://www.example.com (301)

2️⃣ Rewrite Rules

Changes URL internally without redirecting browser.

User sees:

example.com/blog

Backend receives:

example.com/index.php?page=blog

Used in:

  • Clean URLs
  • SEO routing
  • API version mapping

3️⃣ Header Rules

Modify request or response headers.

Examples:

Add security header:

Strict-Transport-Security
X-Frame-Options
X-Content-Type-Options

Add cache control:

Cache-Control: max-age=3600

Used for:

  • Security hardening
  • Performance tuning
  • CORS handling

4️⃣ Cache Rules

Control what gets cached.

Examples:

Cache only:

/images/*
/static/*

Don’t cache:

/api/*
/admin/*

Important for:

  • Performance
  • Reducing backend load
  • Scaling

5️⃣ Rate Limiting Rules

Protect against abuse.

Example:

If IP sends > 100 requests per minute
→ Block for 10 minutes

Used for:

  • Prevent brute force
  • Protect login APIs
  • Stop scraping
  • Stop DDoS (basic layer)

6️⃣ Firewall / WAF Rules

Security filtering layer.

Block based on:

  • IP
  • Country
  • User-Agent
  • Path
  • Bot score
  • Request pattern

Example:

If country == X
→ Block

Or:

If path contains /wp-admin
→ Challenge

7️⃣ Origin Routing Rules

Control backend routing.

Example:

If path starts with /api
→ Send to backend A

If path starts with /static
→ Send to backend B

Used in:

  • Microservices
  • Kubernetes ingress
  • Multi-server architecture

🔥 Rule Evaluation Order (CRITICAL)

This is very important in interviews.

Rules are evaluated:

  1. Top → Bottom
  2. First match wins (usually)

So order matters.

If you place:

Rule 1: Redirect all traffic Rule 2: Allow /health

Rule 2 will never execute.

🔥 Common Production Mistakes

❌ Redirect Loop

Redirecting HTTP → HTTPS while server already forces HTTPS.

❌ Blocking Yourself

Firewall rule blocks your office IP.

❌ Caching API Responses

Leads to users seeing wrong data.

❌ Rate limiting Load Balancer Health Checks

System marks server unhealthy.

🔥 DevOps Debug Strategy for Rule Issues

If something breaks:

  1. Check redirect status code:
curl -I domain
  1. Check headers:
curl -I -v domain

  1. Check rule order

  2. Temporarily disable suspicious rule

  3. Check logs