docker/mod/core/web/turn-stun-servers.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="stun1" class="org.bigbluebutton.web.services.turn.StunServer">
        <constructor-arg index="0" value="{{ .Env.STUN_SERVER }}"/>
    </bean>

    {{if .Env.TURN_SERVER }}
        <bean id="turn0" class="org.bigbluebutton.web.services.turn.TurnServer">
            <constructor-arg index="0" value="{{ .Env.TURN_SECRET }}"/>
            <constructor-arg index="1" value="{{ .Env.TURN_SERVER }}"/>
            <constructor-arg index="2" value="86400"/>
        </bean>
    {{end}}

    <bean id="stunTurnService" class="org.bigbluebutton.web.services.turn.StunTurnService">
        <property name="stunServers">
            <set>
                <ref bean="stun1" />
            </set>
        </property>
        <property name="turnServers">
            <set>
                {{if .Env.TURN_SERVER }}
                <ref bean="turn0" />
                {{end}}
            </set>
        </property>
        <property name="remoteIceCandidates">
            <set>
            </set>
        </property>
    </bean>
</beans>