Logging to custom defined json with dropwizard

Config.java

//
// Wire
// Copyright (C) 2016 Wire Swiss GmbH
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see http://www.gnu.org/licenses/.
//

package com.wire.bots.echo;

import com.wire.bots.sdk.Configuration;
import io.dropwizard.logging.LoggingFactory;

public class Config extends Configuration {
    public String ingress;
    public int portMin;
    public int portMax;
    public String module;

    public String getIngress() {
        return ingress;
    }

    public int getPortMin() {
        return portMin;
    }

    public int getPortMax() {
        return portMax;
    }

    public String getModule() {
        return module;
    }


    @Override
    public synchronized LoggingFactory getLoggingFactory() {
        return new LogbackAutoConfigLoggingFactory();
    }
}

CustomLoggingLayout.java

package com.wire.bots.echo;

import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.CoreConstants;
import ch.qos.logback.core.LayoutBase;

import java.time.Instant;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.util.Map;

public class CustomLoggingLayout extends LayoutBase<ILoggingEvent> {

    private static final DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ISO_DATE_TIME.withZone(ZoneOffset.UTC);

    @Override
    public String doLayout(ILoggingEvent event) {
        StringBuffer buffer = new StringBuffer(256);
        buffer.append("{");

        appendJson(buffer, "@timestamp", formatTime(event));

        Map<String, String> mdc = event.getMDCPropertyMap();
        if (mdc.containsKey("infra_request")) {
            appendJson(buffer, "infra_request", mdc.get("infra_request"));
        }

        if (mdc.containsKey("app_request")) {
            appendJson(buffer, "app_request", mdc.get("app_request"));
        }

        appendJson(buffer, "logger", event.getLoggerName());
        appendJson(buffer, "message", event.getFormattedMessage());
        appendJson(buffer, "level", event.getLevel().levelStr);
        appendJson(buffer, "thread_name", event.getThreadName(), "");

        buffer.append("}")
                .append(CoreConstants.LINE_SEPARATOR);

        return buffer.toString();
    }

    private void appendJson(StringBuffer buffer, String key, String value) {
        appendJson(buffer, key, value, ",");
    }

    private void appendJson(StringBuffer buffer, String key, String value, String ending) {
        buffer.append("\"")
                .append(key)
                .append("\":\"")
                .append(value)
                .append("\"")
                .append(ending);
    }

    private String formatTime(ILoggingEvent event) {
        return dateTimeFormatter.format(Instant.ofEpochMilli(event.getTimeStamp()));
    }
}

logback.xml

<configuration>
    <appender name="local" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{dd/MM/yyyy HH:mm:ss} [%level] [%X{mdc-val}] %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="prod" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
            <layout class="com.wire.bots.echo.CustomLoggingLayout"/>
        </encoder>
    </appender>


    <if condition='"${JSON_LOGGING:-false}".equalsIgnoreCase("true")'>
        <then>
            <root level="INFO">
                <appender-ref ref="prod"/>
            </root>
        </then>
        <else>
            <root level="DEBUG">
                <appender-ref ref="local"/>
            </root>
        </else>
    </if>

    <logger name="org.eclipse.jetty" level="INFO"/>
    <logger name="io.netty" level="INFO"/>
    <logger name="com.wire" level="DEBUG"/>

</configuration>

LogbackAutoConfigLoggingFactory.java

package com.wire.bots.echo;

import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.util.ContextInitializer;
import ch.qos.logback.core.joran.spi.JoranException;
import com.codahale.metrics.MetricRegistry;
import com.fasterxml.jackson.annotation.JsonIgnore;
import io.dropwizard.logging.LoggingFactory;
import io.dropwizard.logging.LoggingUtil;

/**
 * https://github.com/dropwizard/dropwizard/issues/1567
 * Override getLoggingFactory for your configuration
 */
public class LogbackAutoConfigLoggingFactory implements LoggingFactory {

    @JsonIgnore
    private final LoggerContext loggerContext;
    @JsonIgnore
    private final ContextInitializer contextInitializer;

    public LogbackAutoConfigLoggingFactory() {
        this.loggerContext = LoggingUtil.getLoggerContext();
        this.contextInitializer = new ContextInitializer(loggerContext);
    }

    @Override
    public void configure(MetricRegistry metricRegistry, String name) {
        try {
            contextInitializer.autoConfig();
        } catch (JoranException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void stop() {
        loggerContext.stop();
    }

    @Override
    public void reset() {
        loggerContext.reset();
    }
}

pom.xml

        <dependency>
            <groupId>org.codehaus.janino</groupId>
            <artifactId>janino</artifactId>
            <version>3.1.2</version>
        </dependency>