Add a hook to Sentry Logback to scrub data - scala

Question

I'm using the Logback SDK for Java to send events to Sentry as described in the documentation.
Snippet:
<conversionRule conversionWord="CUSTOM_CONVERSION_RULE"
converterClass="clazz..." />
...
<property scope="context" name="myEnc" value="%d{ISO8601,UTC} | %-5level | %-50thread | %-55logger{55} | %CUSTOM_CONVERSION_RULE" />
...
<appender name="SENTRY" class="io.sentry.logback.SentryAppender">
<dsn>...</dsn>
<encoder>${myEnc}</encoder>
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>ERROR</level>
</filter>
</appender>
....
The initial problem was that the events sent to Sentry were not converted by my custom conversion rule. All the other appenders such as Console that use the property myEnc containing the conversion rule parse the data as expected. But it seems that the io.sentry.logback.SentryAppender in combination with the encoder somehow doesn't do that. The filter property is working as well as the dsn one, so I get the errors in Sentry but not with my custom parsing.
The version that I use for io.sentry.sentry-logback (and transitively sentry) is 1.7.24.
I then read about before-send hook from Sentry docs which is what I want to control what data is sent to Sentry and I had to upgrade to latest for that which is 3.1.3 at the time of writing this.
The Logback XML config changed a bit:
<appender name="SENTRY" class="io.sentry.logback.SentryAppender">
<options>
<dsn>...</dsn>
<beforeSend>????</beforeSend>
</options>
...
</appender>
From what I can see the before-send hook is exactly what I need to scrub the data when required because I don't want some info to be sent to Sentry. docs
Now, the second issue is that I don't know how to ref here a method. In the Java config there is a BiFunction that takes the event and can alter it. But I want to apply this hook to all my log events, that's why the only place it is configured is in the Logback SDK.
In Spring Boot for example there is a starter for Sentry and, off course, a bean that you can inject in the auto-configuration.
But, I'm using Scala with no Spring Boot.
Also, the project is already in prod so I cannot change lots of things and I'm looking for the smallest one that will allow me to add a hook to Logback's SDK for Sentry.
Here is the appender and it looks like (I'm not sure how it works) the options can be populated from XML and than pass to init that will take all them into account, including my before send hook.
I don't know if it's accepted to have two questions and only one referenced in the title but I didn't find a nicer way to ask/explain the problem, because one thing lead to another.
To summarize the questions:
Why that custom rule is not working with Logback Sentry's appender.
How can I let the appender know about my hook and use it.
Thanks in advance!

Answer 1

You can configure Sentry independently from appender configuration in logback.xml. For example:
public class Main {
private static final Logger LOGGER = LoggerFactory.getLogger(Main.class);
static {
Sentry.init(options -> {
options.setDsn("PUT YOUR DSN HERE");
options.setBeforeSend((sentryEvent, o) -> {
sentryEvent.setTag("custom", "tag");
return sentryEvent;
});
});
}
public static void main(String[] args) {
LOGGER.error("oops");
}
}
<configuration>
<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<appender name="sentry" class="io.sentry.logback.SentryAppender" />
<root level="debug">
<appender-ref ref="console"/>
<appender-ref ref="sentry"/>
</root>
</configuration>
Check complete code sample in github repo: https://github.com/maciej-scratches/sentry-logback-custom-config