A logback discriminator for the akkaSource MDC value.

AkkaSourceDiscriminator.java

package se.fishtank;

import java.net.URI;
import java.util.Map;

import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.sift.Discriminator;
import ch.qos.logback.core.spi.ContextAwareBase;

public class AkkaSourceDiscriminator extends ContextAwareBase implements Discriminator<ILoggingEvent> {

    private String key;

    private String defaultValue;

    private String actorPathContains;

    private boolean onlyUseActorName = true;

    private boolean started = false;

    @Override
    public String getDiscriminatingValue(ILoggingEvent event) {
        Map<String, String> mdc = event.getMDCPropertyMap();
        if (mdc == null) return defaultValue;

        String value = mdc.get("akkaSource");
        if (value == null || !value.contains(actorPathContains)) return defaultValue;

        String path = getPath(value);
        if (path == null || "/".equals(path)) return defaultValue;

        if (onlyUseActorName) {
            int idx = path.lastIndexOf('/');
            if (idx == -1) return defaultValue;
            return path.substring(idx + 1);
        } else {
            if (path.charAt(0) == '/')
                path = path.substring(1);

            return path.replace('/', '-');
        }
    }

    @Override
    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public void setDefaultValue(String defaultValue) {
        this.defaultValue = defaultValue;
    }

    public void setActorPathContains(String actorPathContains) {
        this.actorPathContains = actorPathContains;
    }

    public void setOnlyUseActorName(String value) {
        if (value != null) {
            if ("true".equals(value)) {
                onlyUseActorName = true;
            } else if ("false".equals(value)) {
                onlyUseActorName = false;
            } else {
                throw new IllegalArgumentException("Expected \"true\" or \"false\" for property \"OnlyUseActorName\"");
            }
        }
    }

    @Override
    public void start() {
        started = isValid("Key", key)
                && isValid("DefaultValue", defaultValue)
                && isValid("ActorPathContains", actorPathContains);
    }

    @Override
    public void stop() {
        started = false;
    }

    @Override
    public boolean isStarted() {
        return started;
    }

    private String getPath(String akkaSource) {
        try {
            return new URI(akkaSource).getPath();
        } catch (Exception e) {
            return null;
        }
    }

    private boolean isValid(String property, String value) {
        if (value == null || value.isEmpty()) {
            addError("The \"" + property + "\" property must be set");
            return false;
        }

        return true;
    }

}

logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="false" debug="false">
  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
        <pattern>%date{ISO8601} %-5level %logger{36} %X{akkaSource} %X{sourceThread} - %msg%n</pattern>
    </encoder>
  </appender>

  <appender name="FILE_DEBUG" class="ch.qos.logback.core.FileAppender">
    <file>/tmp/debug.log</file>
    <encoder>
      <pattern>%date{ISO8601} %-5level %logger{36} %X{akkaSource} %X{sourceThread} - %msg%n</pattern>
    </encoder>
  </appender>

  <appender name="SIFT_ACTOR1" class="ch.qos.logback.classic.sift.SiftingAppender">
    <discriminator class="se.fishtank.AkkaSourceDiscriminator">
      <key>actor</key>
      <defaultValue>unknown</defaultValue>
      <!-- What the actor path should contain to consider this a match. -->
      <actorPathContains>actor1</actorPathContains>
      <!-- Uncomment the stuff below to use the full actor path as the filename. -->
      <!--
      <onlyUseActorName>false</onlyUseActorName>
      -->
    </discriminator>
    <sift>
      <appender name="FILE_ACTOR_${actor}" class="ch.qos.logback.core.FileAppender">
        <file>/tmp/${actor}.log</file>
        <encoder>
          <pattern>%date{ISO8601} %-5level %logger{36} %X{akkaSource} %X{sourceThread} - %msg%n</pattern>
        </encoder>
      </appender>
    </sift>
  </appender>

  <root level="DEBUG">
    <appender-ref ref="STDOUT"/>
    <appender-ref ref="FILE_DEBUG"/>
    <appender-ref ref="SIFT_ACTOR1"/>
  </root>
</configuration>

When setting <onlyUseActorName>false</onlyUseActorName> the full actor path will be used as the filename prefix. I.e. if the path is /user/foo/bar the filename prefix will be user-foo-bar.