camptocamp/tomcat-logback repository overview

⁠Docker image for tomcat with logback integration

Based on the official tomcat image, but with logs using logback.

⁠Tunning

Some environment variables are available to tune the logs:

• DEFAULT_LOG_LEVEL: Set the default log level.
• TOMCAT_LOG_LEVEL: Set the tomcat log level.
• SENTRY_LOG_LEVEL: Set the Sentry log level.
• SENTRY_REPORTING_LOG_LEVEL: Starting from what log level to report to Sentry.
• TOMCAT_LOG_TYPE:
  • classic (default): The logs are humane readable. Access logs are going to stdout and the other logs are going to stderr.
  • json: The logs will be formatted in a JSON suitable for logstash. Access logs are going to stdout and the other logs are going to stderr.
  • logstash: The logs will be formatted in a JSON suitable for logstash (@cee) and sent by syslog/UDP. The access logs are going to stdout in json format. More variables are available for this mode:
    • TOMCAT_LOG_HOST: the target host
    • TOMCAT_LOG_PORT: the target port

If you want to change the way things are logged, change the ${CATALINA_HOME}/conf/logback-custom.xml file.

If your application uses logback/log4j, it is recommended to not ship those libraries with your webapp. Just use the ones provided at tomcat level.

⁠Integration with Sentry

You can enable Sentry crash reports by adding a parameter to the CATALINA_OPTS environment variable with the DSN provided by sentry:

• -Dsentry.dsn=https://public:private@host:port/1⁠

Other parameters are documented here: https://docs.sentry.io/clients/java/config/⁠

⁠Other changes

Other changes compared the official tomcat image:

• All the default webapps are removed.
• TLD and JAR scanners are disabled (faster startup).
• Resources caching is properly configured.