Load Balancer with HAProxy SSL Termination

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Load Balancer is the sister of cluster so If you make Ant Media Server instances run in Cluster Mode. Then a load balancer will be required to balance the load.

In this documentation, you will learn how to install HAProxy Load Balancer with SSL termination

The configuration below balances RTMP, HLS, HTTP/HTTPS and WebSocket(WS/WSS) connections so that it will be used for RTMP, HLS and WebRTC streaming.

Installation

Install HAProxy

You can install HAProxy to both one of the instances that run on Ant Media Server or you can make it run on different instance. For our case, we assume that HAProxy runs on a specific instance. So let's install HAProxy

sudo apt-get install haproxy

Install SSL Certificate

If you need to support SSL in load balancer, install the certbot as follows. If you do not plan to support SSL, you can skip this section to Configuration HAProxy

sudo apt-get update
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update
sudo apt-get install certbot

Prepare the Certificate

Run the command below to get the certificate, please change example.com with your domain name

sudo certbot certonly --standalone -d example.com -d www.example.com

Combine fullchain.pem and privkey.pem and save it to /etc/haproxy/certs folder

sudo mkdir -p /etc/haproxy/certs
DOMAIN='example.com' sudo -E bash -c 'cat /etc/letsencrypt/live/$DOMAIN/fullchain.pem /etc/letsencrypt/live/$DOMAIN/privkey.pem > /etc/haproxy/certs/$DOMAIN.pem'
sudo chmod -R go-rwx /etc/haproxy/certs

Right now required pem file ready under /etc/haproxy/certs folder to use in HAProxy

Configuring HAProxy

Move the default configuration file

mv /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.original

Create and edit new configuration file

nano /etc/haproxy/haproxy.cfg

Global and Default Parameters

global
    log 127.0.0.1 local0 notice
    maxconn 2000
    user haproxy
    group haproxy
defaults
    log global
    mode http
    option forwardfor
    option http-server-close
    option httplog
    option dontlognull
    timeout connect 5000
    timeout client  5000
    timeout server  5000
    timeout tunnel  2h  #this is for websocket connections, 2 hours inactivity timeout
    timeout client-fin 5000
    errorfile 400 /etc/haproxy/errors/400.http
    errorfile 403 /etc/haproxy/errors/403.http
    errorfile 408 /etc/haproxy/errors/408.http 
    errorfile 500 /etc/haproxy/errors/500.http
    errorfile 502 /etc/haproxy/errors/502.http
    errorfile 503 /etc/haproxy/errors/503.http
    errorfile 504 /etc/haproxy/errors/504.http

The configuration above makes maximum number of connections to 2000. Please change it according to your hardware and cluster size.

Monitoring Parameters

listen stats # Define a listen section called "stats"
  bind :6080 
  mode http
  stats enable  # Enable stats page
  stats hide-version  # Hide HAProxy version
  stats realm Haproxy\ Statistics  # Title text for popup window
  stats uri /haproxy_stats  # Stats URI
  stats auth Username:Password  # Authentication credentials

With the configuration above when you go to http://HAPROXY_LB:6080/haproxy_stats URL, you can authenticate with Username and Password so that specify username and password.

RTMP Load Balancing

frontend rtmp_lb
    bind *:1935 
    mode tcp
    default_backend backend_rtmp

backend backend_rtmp
    mode tcp
    server ams1 172.30.0.42:1935 check  # Ant Media Server instance 1
    server ams2 172.30.0.48:1935 check  # Ant Media Server instance 2
    # you can add more instances 

HTTP/HTTPS Load Balancing

frontend http_lb
  bind *:80
  bind *:5080
  mode http
  reqadd X-Forwarded-Proto:\ http
  default_backend backend_http

# if you install SSL above add below frontend_https
frontend frontend_https
  bind *:443 ssl crt  /etc/haproxy/certs/$DOMAIN.pem
  bind *:5443 ssl crt /etc/haproxy/certs/$DOMAIN.pem
  reqadd X-Forwarded-Proto:\ https
  default_backend backend_http


backend backend_http
  # below line forwards http requests to https, if you do not have SSL termination, remove it
  redirect scheme https if ! { ssl_fc }  
  # below line provides session stickiness
  cookie JSESSIONID prefix nocache  
  server ams1 172.30.0.42:5080 check cookie ams1  #if you do not use session stickiness, remove cookie ams1
  server ams2 172.30.0.42:5080 check cookie ams2  #if you do not use session stickiness, remove cookie ams2
    # you can add more instances 

Note: Even if you don't want to use sticky sessions for http requests, you must use it for HLS playing (m3u8 and ts) requests due to performance issues and correctness of statistics. You can configure HAProxy as follows to make only HLS session sticky.

frontend http_lb
  bind *:80
  bind *:5080
  acl hls_request path_reg -i ^.*\.(m3u8|ts)$
  mode http
  use_backend backend_http_sticky if hls_request
  default_backend backend_http

backend backend_http
  mode http
  server ams1 172.17.0.2:5080 check   
  server ams2 172.17.0.3:5080 check   

backend backend_http_sticky
  mode http
  cookie JSESSIONID prefix nocache  
  server ams1 172.17.0.2:5080 check cookie ams1  
  server ams2 172.17.0.3:5080 check cookie ams2  

Starting HAProxy

When everything is comple restart the HAProxy

sudo service haproxy restart

and you can view status of the instance throught http://HAPROXY_LB:6080/haproxy_stats URL

If you have a question, please let us know through [email protected]