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The Logger

Overview

The Logging Control Server (log_cs) is the centralized sink for CGSE logs. Processes send log records over ZeroMQ to log_cs, which writes to rotating files, prints selected levels to stdout, and can optionally forward records to an external logger.

In most services, logging forwarding is enabled through egse.logger.setup_logging() or by using the remote_logging() context manager.

Core responsibilities:

  • centralized log ingestion from services
  • rotating file persistence and stdout mirroring
  • optional forwarding to external logging endpoints

Socket Endpoints

The logger uses two endpoints:

Purpose Pattern Your Socket Default Endpoint
Log record ingest PUSH-PULL PUSH tcp://localhost:6105
Logger commands REQ-REP REQ tcp://localhost:6106

Note

These default port values are defined in cgse_core/settings.yaml and can be overridden in the local settings. Ports can be static or dynamically allocated by the OS when configured as 0. Clients discover the active endpoints through the Registry, especially when ports are configured as 0.

Client Access

Use remote_logging() around your service main loop:

from egse.logger import remote_logging

with remote_logging():
    ...

This configures the ZeroMQ log handler so records are forwarded to log_cs.

Control Actions

The command endpoint supports:

  • status
  • set_level <LEVEL>
  • roll (log rotation)
  • quit

Convenience wrappers are exposed via CLI.

Running The Service

uv run cgse log start
uv run cgse log stop
uv run cgse log status

python -m egse.logger.log_cs start
python -m egse.logger.log_cs status
python -m egse.logger.log_cs roll
python -m egse.logger.log_cs stop

Configuration

Settings are loaded from Logging Control Server in cgse_core/settings.yaml. Important keys include:

  • RECEIVER_PORT
  • COMMANDER_PORT
  • MAX_NR_LOG_FILES
  • MAX_SIZE_LOG_FILES
  • EXTERN_LOG_HOST
  • EXTERN_LOG_PORT

Integration Notes

At startup, log_cs registers itself in the Service Registry and publishes:

  • command port as service port
  • receiver port in service metadata (receiver_port)

This enables dynamic endpoint resolution for producers.

Monitoring And Troubleshooting

  • Use uv run cgse log status to inspect active ports, levels, and the location of the log file.
  • If forwarding is missing, verify that Registry is running and log_cs is registered.
  • If startup fails, check that log directory exists and is writable.