Configure NGINX as a reverse proxy for ldaps

stream {
  	map $ssl_preread_server $name {
		idm-site1.corp.com idm_site1;
		idm-site2.corp.com idm_site2;
		idm-site3.corp.com idm_site3;
  	}

	upstream idm_site1 {
		server idm1.corp.com:636;
		server idm2.corp.com:636;
	}

	upstream idm_site2 {
		server idm3.corp.com:636;
		server idm4.corp.com:636;
	}

	upstream idm_site3 {
		server idm5.corp.com:636;
		server idm6.corp.com:636;
	}

	server {
		listen 636 ssl;
		proxy_ssl on;
		ssl_certificate /etc/ssl/certs/idm-site.crt;
		ssl_certificate_key /etc/ssl/private/idm-site.key;
		ssl_password_file /etc/nginx/ssl_password.txt;
		proxy_pass $name;
	}
}