configure-haproxy

name	configure-haproxy
description	Configure HAProxy for TCP or HTTP load balancing, SSL/TLS termination, and ACL-based routing. Use when creating or editing haproxy.cfg files for frontends, backends, and listen sections.
license	Apache-2.0
compatibility	Requires HAProxy 2.8+ (LTS). Available as haproxy:lts-alpine Docker image.
metadata	{"author":"proxy-tools","version":"1.0"}
allowed-tools	docker bash

Configure HAProxy

HAProxy configuration has four main sections: global, defaults, frontend, and backend.

Config Skeleton

global
    log stdout format raw local0 info
    maxconn 50000

defaults
    log    global
    mode   http          # or tcp for L4
    option httplog
    timeout connect 5s
    timeout client  30s
    timeout server  30s

frontend http_front
    bind *:80
    default_backend app_back

backend app_back
    balance roundrobin
    option httpchk GET /healthz
    server web1 web1.internal:8080 check
    server web2 web2.internal:8080 check

Modes

Mode	Use case
http	HTTP/1.1 and HTTP/2 (L7) — inspect/route by URL, headers
tcp	Raw TCP proxy (L4) — databases, SMTP, Redis

Load Balancing Algorithms

roundrobin | leastconn | source (IP hash) | uri | random

Workflow

1. Choose example from haproxy/examples/:
   • http-proxy.cfg — HTTP load balancing with health checks
   • tcp-proxy.cfg — TCP (MySQL, Redis)
   • ssl-termination.cfg — HTTPS termination
   • acl-routing.cfg — Route by host/path/IP
2. Validate:

   haproxy -c -f haproxy/haproxy.cfg
   # or via Docker:
   docker run --rm -v $(pwd)/haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro \
     haproxy:lts-alpine haproxy -c -f /usr/local/etc/haproxy/haproxy.cfg
   

3. Run: docker compose -f haproxy/docker-compose.yml up -d
4. Stats: visit http://localhost:8404/stats

TLS Certificate Format

HAProxy expects a single PEM file: cat fullchain.pem privkey.pem > server.pem

References

• HAProxy docs: https://docs.haproxy.org/
• Repository: haproxy/