Author: Madhan Gopalakrishnan | Published on : 11-02-202
HAProxy (High Availability Proxy) is a powerful, open-source load balancer and proxy server designed to efficiently distribute traffic across multiple servers, ensuring high availability and optimized performance. This guide provides a step-by-step setup, making it easy for beginners and administrators alike! 🛠️
🔧 2. Prerequisites
🌐 2.1 Network Requirements
✔️ A minimum of two backend servers and one HAProxy server ✔️ Static IP addresses assigned to all servers ✔️ Proper DNS resolution for backend servers ✔️ Firewall rules allowing traffic on necessary ports (80, 443 for HTTP/HTTPS, 22 for SSH, etc.)
💻 2.2 Compute Requirements
✅ Minimum: 2 vCPU, 4GB RAM (for small deployments) ✅ Recommended: 4 vCPU, 8GB RAM (for production) ✅ At least 20GB disk space ✅ Operating System: RHEL, CentOS, Ubuntu, or Debian
🛠️ 2.3 Software Requirements
✅ HAProxy package (latest stable version) ✅ OpenSSL for SSL/TLS termination (if required) ✅ System utilities: net-tools, curl, vim or nano
🏗️ 3. Installation of HAProxy
🐧 3.1 Installing on Ubuntu/Debian
sudo apt update # 📌 Updates the package list to get the latest versions
sudo apt install -y haproxy # ⚡ Installs HAProxy without user confirmation
🏗️ 3.2 Installing on CentOS/RHEL
sudo yum install -y epel-release # 📌 Enables Extra Packages for Enterprise Linux (EPEL) repository
sudo yum install -y haproxy # ⚡ Installs HAProxy package
✅ 3.3 Verifying Installation
haproxy -v # 🔍 Displays the installed HAProxy version
⚙️ 4. Step-by-Step Configuration
🏁 4.1 Day 1 Activity (Initial Setup)
🛠️ 4.1.1 Configuring HAProxy
🔹 Backup the default HAProxy configuration file:
sudo cp /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.bak # 🛡️ Creates a backup of the config file
🔹 Open and edit the HAProxy configuration file:
sudo nano /etc/haproxy/haproxy.cfg # ✍ Opens the configuration file in nano editor
🔹 Define the global settings:
global
log /dev/log local0 # 📌 Logs messages to syslog
log /dev/log local1 notice # Defines logging level
chroot /var/lib/haproxy # 🔒 Enhances security
stats socket /run/haproxy/admin.sock mode 660 level admin # 📊 Enables admin stats socket
stats timeout 30s # ⏳ Sets timeout for stats
user haproxy # 👤 Runs HAProxy as user haproxy
group haproxy # 👥 Runs HAProxy as group haproxy
daemon # 🏃 Runs HAProxy in the background
🔹 Configure default settings:
defaults
log global # 📌 Uses global logging settings
mode http # 🌍 Sets mode to HTTP for web traffic
option httplog # 📝 Enables logging for HTTP requests
timeout connect 5000ms # ⏳ Connection timeout
timeout client 50000ms # ⏳ Client timeout
timeout server 50000ms # ⏳ Server timeout
🔹 Define frontend configuration:
frontend http_front
bind *:80 # 🔗 Listens on port 80 for incoming requests
default_backend web_servers # 📌 Sends traffic to backend servers
🔹 Define backend configuration:
backend web_servers
balance roundrobin # 🔄 Distributes traffic evenly among backend servers
server web1 192.168.1.101:80 check # 🖥️ First backend server with health check
server web2 192.168.1.102:80 check # 🖥️ Second backend server with health check
🔹 Save the configuration and restart HAProxy:
sudo systemctl restart haproxy # 🔄 Restarts HAProxy to apply changes
sudo systemctl enable haproxy # 🚀 Enables HAProxy to start on boot
🔹 Verify HAProxy status:
sudo systemctl status haproxy # ✅ Checks if HAProxy is running
📊 4.2 Day 2 Activity (Monitoring & Optimization)
📈 4.2.1 Enabling HAProxy Stats Page
🔹 Modify haproxy.cfg to add a stats section:
listen stats
bind *:8080 # 📡 Listens on port 8080 for the stats page
stats enable # 📊 Enables statistics
stats uri /stats # 🔍 Defines the URL to access stats
stats auth admin:password # 🔑 Sets username and password for stats page
🔹 Restart HAProxy:
sudo systemctl restart haproxy # 🔄 Restart HAProxy with updated config
🔹 Access the stats page: http://<haproxy-ip>:8080/stats 📊
📜 4.2.2 Setting Up Logging
🔹 Ensure rsyslog is installed and configured:
sudo apt install -y rsyslog # 🐧 For Ubuntu/Debian
sudo yum install -y rsyslog # 🏗️ For RHEL/CentOS
🔹 Enable HAProxy logging:
sudo nano /etc/rsyslog.d/haproxy.conf # ✍ Creates a log config file
🔹 Add the following:
local0.* /var/log/haproxy.log # 📌 Sends HAProxy logs to a dedicated file
🔹 Restart rsyslog:
sudo systemctl restart rsyslog # 🔄 Restarts rsyslog to apply changes
🔒 4.2.3 Configuring SSL Termination (Optional)
🔹 Obtain an SSL certificate (self-signed or from Let’s Encrypt). 🔹 Configure HAProxy to use SSL:
frontend https_front
bind *:443 ssl crt /etc/haproxy/certs/server.pem # 🔒 Uses SSL certificate
default_backend web_servers # 🚀 Routes traffic to backend servers
🔹 Restart HAProxy:
sudo systemctl restart haproxy # 🔄 Restarts HAProxy with SSL settings
🎯 5. Conclusion
By following this guide, you have successfully installed, configured, and optimized HAProxy for high availability and efficient load balancing. 🌍🚀 Keep monitoring your setup to ensure seamless operations! 🔍💡
