Logging

The Negotiator uses Logback to handle logging.

Default Configuration

Logback is configured, among other settings, in the application.yaml file.

By default, the development environment is configured to output logs only to the console, and the logging level is set to DEBUG. For the production profile, the logging level is set to INFO.

For production environments, the default configuration can be found in the application file.

The configuration uses a SizeAndTimeBasedRollingPolicy, which keeps the default time range (i.e., 1 day). This means a new log file will be created each day. If the log file reaches the maximum file size (10MB) before the day ends, a new log file is created, and the previous one is archived.

The file name pattern for logs is: negotiator.log.%d{%YYY-MM-dd}.%i.cz

To control storage consumption, the max-history parameter is configured to 30 (i.e., logs are retained for one month), meaning that logs older than 30 days will be deleted automatically.

All configuration parameters can be overridden using environment variables.

By default, logs are stored in the /var/log/negotiator/ directory.

Accessing Logs

To view the logs from a running Docker container, you can use the following command:

docker logs <container_name_or_id>

Viewing Container Stats

To view the resource usage and stats of a running Docker container, such as CPU and memory usage, you can use the docker stats command:

docker stats <container_name_or_id>

Customizing Log Level through Environment Variables

In Spring applications, you can customize the log level dynamically through environment variables. This is particularly useful when deploying to different environments (e.g., development, staging, production). To change the log level, you can set the property in the environment.

logging.level.<logger_name>

For example, to set the log level for the root logger to DEBUG, you can use the environment variable:

LOGGING_LEVEL_ROOT=DEBUG

Similarly, you can customize the log level for specific packages or classes by specifying the package or class name. For instance, to set the log level for the com.example package to INFO, use

LOGGING_LEVEL_COM_EXAMPLE=INFO

These environment variables can be passed in the Docker Compose file or directly to the application at runtime, allowing you to fine-tune logging without modifying application configuration files.