configuring-load-balancers

name	configuring-load-balancers
description	Configure use when configuring load balancers including ALB, NLB, Nginx, and HAProxy. Trigger with phrases like "configure load balancer", "create ALB", "setup nginx load balancing", or "haproxy configuration". Generates production-ready configurations with health checks, SSL termination, sticky sessions, and traffic distribution rules.
allowed-tools	Read, Write, Edit, Grep, Glob, Bash(aws:*), Bash(gcloud:*), Bash(nginx:*)
version	1.28.0
author	Jeremy Longshore <[e-mail]>
license	MIT
tags	["devops","load-balancers"]
compatibility	Designed for Claude Code

Configuring Load Balancers

Overview

Configure load balancers across AWS (ALB, NLB), GCP (HTTP(S) LB, TCP/UDP LB), Nginx, and HAProxy. Generate production-ready configurations with health checks, SSL/TLS termination, path-based and host-based routing, sticky sessions, rate limiting, and traffic distribution rules for high-availability deployments.

Prerequisites

• Backend servers identified with IPs, DNS names, and ports
• Load balancer type determined: L4 (NLB, HAProxy TCP) or L7 (ALB, Nginx, HAProxy HTTP)
• SSL/TLS certificates available (ACM, Let's Encrypt, or self-signed) if using HTTPS
• Health check endpoints defined on backend services (e.g., /health returning 200)
• Cloud provider CLI installed for managed load balancers (aws, gcloud)

Instructions

1. Select load balancer type based on requirements: ALB for HTTP/HTTPS with path routing, NLB for TCP/UDP with static IPs, Nginx for on-prem reverse proxy, HAProxy for high-performance TCP/HTTP
2. Define the backend pool: list all backend server addresses, ports, and weights for weighted distribution
3. Configure health checks with appropriate interval (10-30s), timeout (5s), healthy threshold (3), and unhealthy threshold (2)
4. Set up SSL/TLS termination: configure certificates, redirect HTTP to HTTPS, set minimum TLS version to 1.2
5. Define routing rules: path-based routing (/api -> API pool, /static -> CDN), host-based routing (api.example.com -> API)
6. Enable session persistence (sticky sessions) using cookies or source IP affinity where needed for stateful applications
7. Add connection draining to gracefully handle backend removal during deployments
8. Configure logging and monitoring: access logs to S3/CloudWatch, request metrics, error rate dashboards
9. Test the configuration: validate syntax (nginx -t, HAProxy config check), verify traffic distribution, and confirm failover behavior

Output

• Nginx configuration files (nginx.conf, site configs) with upstream blocks and server directives
• HAProxy configuration (haproxy.cfg) with frontend/backend sections
• Terraform HCL for AWS ALB/NLB with target groups, listeners, and rules
• GCP load balancer Terraform with backend services, URL maps, and health checks
• SSL certificate configuration and renewal automation

Error Handling