Reviewed on: 2019-08-30
logger is the main logging service on Fuchsia. It provides the fuchsia.logger.LogSink service which components use to log messages, and the fuchsia.logger.Log service which log_listener uses to read back logs. It has a 4 MB rotating buffer in which all logs are stored. It also reads the kernel log and merges log messages from it into its buffer.
This project is included in the core build product.
The diagnostics archivist is started on-demand by clients connecting to the LogSink protocol. In practice this means an instance is usually running already.
Unit tests are available in the archivist_tests package.
Integration tests for system logging are available in the logger_integration_tests package.
$ fx run-test archivist_tests $ fx run-test logger_integration_tests
The entrypoint is located in src/main.rs, with the rest of the code living in src/*.rs files. Unit tests are co-located with the code and integration tests are located in the tests/ directory.