We need to configure a net.logstash.logback.appender.LogstashTcpSocketAppender to connect to DataDog, however, the server that needs to send out these logs only works with a proxy. We are running on WebSphere Application Server.

We tried settings the -Dhttp.proxyHost and -Dhttp.proxyPort and -Dhttps.proxyHost and -Dhttps.proxyPort in Application servers, our instance, Process definition, Java Virtual Machine in Generic JVM Arguments, but other then messing up the other http calls, it did nothing for the appender.

How can I configure the proxy for the LogstashTcpSocketAppender, without overriding every http call with JVM settings?

    <!-- See https://docs.datadoghq.com/logs/log_collection/java/?tab=log4j&site=eu for the JSON_TCP appender -->
    <appender name="JSON_TCP" class="net.logstash.logback.appender.LogstashTcpSocketAppender">
        <destination>tcp-intake.logs.datadoghq.eu:443</destination>
        <keepAliveDuration>20 seconds</keepAliveDuration>
        <encoder class="net.logstash.logback.encoder.LogstashEncoder">
            <prefix class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
                <layout class="ch.qos.logback.classic.PatternLayout">
                    <pattern>API_KEY_OMITTED %mdc{keyThatDoesNotExist}</pattern>
                </layout>
            </prefix>
        </encoder>
        <addDefaultStatusListener>false</addDefaultStatusListener>
        <writeBufferSize>1024</writeBufferSize>
    </appender>