Logback encoders are not working with LoggingAppender

[Khidala]

Logback encoders are not working with LoggingAppender. Can encoders be used with LoggingAppender for layout/pattern usage?

Environment details

Need to use https://logback.qos.ch/manual/encoders.html with google-cloud-logging-logback, but it doesn't work when I use encoder with google-cloud-logging-logback version 0.130.17-alpha.

Steps to reproduce

1. Use LoggingAppender in logback.xml
2. Add encoder element to logback.xml.

Code example

Contents of logback.xml:

<configuration>
  <appender name="CLOUD" class="com.google.cloud.logging.logback.LoggingAppender">
    <!-- Optional : filter logs at or above a level -->
    <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
      <level>DEBUG</level>
    </filter>
    <log>application.log</log> <!-- Optional : default java.log -->
    <resourceType>gae_app</resourceType> <!-- Optional : default: auto-detected, fallback: global -->
    <enhancer>com.server.utils.LoggingEnhancerSimple</enhancer> <!-- Optional -->
    <flushLevel>WARN</flushLevel> <!-- Optional : default ERROR -->
    <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
      <pattern>%d %-5level [%thread] %logger{0}: %msg%n</pattern>
    </encoder>
  </appender>

  <root level="debug">
    <appender-ref ref="CLOUD" />
  </root>
</configuration>

Stack trace

In App Engine Standard Java 17 log I see this error at startup:
`ERROR in ch.qos.logback.core.joran.spi.Interpreter@12:16 - no applicable action for [pattern], current ElementPath  is [[configuration][appender][encoder][pattern]]`

External references such as API reference guides

https://github.com/googleapis/java-logging-logback
See "Usage" section which says encoders can be used with LoggingAppender.

[peterweb2005]

excuse me

how is the status? Reminded to migrate on January 30, 2024

thanks

[cindy-peng]

Hi @peterweb2005 , I am sorry about the late reply. Are you still running into this issue?

[cindy-peng]

Hi @peterweb2005 , if you are still running into this issue, could you help provide the most recent repro? Thank you!

[PiotrSierkin-Ki]

@cindy-peng

Having similar issue where my encoder is not being respected by appender <appender name="GCP" class="com.google.cloud.logging.logback.LoggingAppender">

Versions:

• gcp-logback = "0.131.11-alpha"

Example 1
Config

<configuration>
    <appender name="GCP" class="com.google.cloud.logging.logback.LoggingAppender">
        <redirectToStdout>true</redirectToStdout>
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d %-5level [%thread] %logger{0}: %msg%n</pattern>
        </encoder>
    </appender>
    <root level="INFO">
        <appender-ref ref="GCP" />
    </root>
    <logger name="org.eclipse.jetty" level="INFO"/>
    <logger name="io.netty" level="INFO"/>
</configuration>

Logs

14:59:41,921 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - Processing appender named [GCP]
14:59:41,921 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - About to instantiate appender of type [com.google.cloud.logging.logback.LoggingAppender]
14:59:41,929 |-WARN in ch.qos.logback.core.model.processor.ImplicitModelHandler - Ignoring unknown property [encoder] in [com.google.cloud.logging.logback.LoggingAppender]

Example 2
Config

<configuration>
    <appender name="GCP" class="com.google.cloud.logging.logback.LoggingAppender">
        <redirectToStdout>true</redirectToStdout>
        <encoder class="net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder">
            <providers>
                <pattern>
                    <omitEmptyFields>true</omitEmptyFields>
                    <pattern>
                        {
                        "logger": "%logger",
                        "level": "%level",
                        "thread": "%thread",
                        "message": "%message",
                        "traceId": "%mdc{traceId}"
                        }
                    </pattern>
                </pattern>
            </providers>
        </encoder>
    </appender>

    <root level="INFO">
        <appender-ref ref="GCP" />
    </root>

    <logger name="org.eclipse.jetty" level="INFO"/>
    <logger name="io.netty" level="INFO"/>
</configuration>

Logs

15:17:20,848 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - Processing appender named [GCP]
15:17:20,848 |-INFO in ch.qos.logback.core.model.processor.AppenderModelHandler - About to instantiate appender of type [com.google.cloud.logging.logback.LoggingAppender]
15:17:20,861 |-WARN in ch.qos.logback.core.model.processor.ImplicitModelHandler - Ignoring unknown property [encoder] in [com.google.cloud.logging.logback.LoggingAppender]

What I wanted to achieve

Basically right now I am struggling with modifying my gcp logs to be in jsonPayload rather than in textPayload (using appender with this config

<configuration>
    <appender name="GCP" class="com.google.cloud.logging.logback.LoggingAppender">
        <redirectToStdout>true</redirectToStdout>
    </appender>
    <root level="INFO">
        <appender-ref ref="GCP" />
    </root>
    <logger name="org.eclipse.jetty" level="INFO"/>
    <logger name="io.netty" level="INFO"/>
</configuration>

work great I have everything that I need but I am missing part where I could parse my textPayload to jsonPayload)

Note: message is saved as textPayload if it is the only field remaining after the Logging agent moves the other special-purpose fields and detect_json wasn't enabled; otherwise message remains in jsonPayload. detect_json is not applicable to managed logging environments like Google Kubernetes Engine. If your log entry contains an exception stack trace, the exception stack trace should be set in this message JSON log field, so that the exception stack trace can be parsed and saved to Error Reporting.

• Don't know how to achieve that