nornir-shared

nornir_shared is the common utilities package used by every other Nornir project. It owns the logging convention, console/UI output helpers, filesystem utilities, and lightweight parallelism helpers that do not belong in any single domain package.

• Repository: nornir-shared/

• Python import: nornir_shared

Key modules

nornir_shared.misc

The primary utilities module. Key APIs:

SetupLogging()

Initialise file logging for the current process. Reads NORNIR_LOG_ROOT to determine the root directory for session log files. Safe to call multiple times (idempotent handlers).

StartMultiprocessLoggingListener()

Start a queue-based logging listener in the parent process before spawning workers. Returns the multiprocessing.Queue to pass to workers.

ConfigureWorkerQueueLogging(queue)

Call in each worker process to route all log records through the shared queue to the parent listener (avoids concurrent file writes).

StopMultiprocessLoggingListener()

Gracefully shut down the listener after all workers have finished.

See Logging convention for the full logging guide, including environment variables, session file layout, and multiprocessing patterns.

nornir_shared.prettyoutput

Console and UI presentation helpers (progress indicators, coloured status lines). Not a logging sink — do not use this module to write persistent log files.

nornir_shared.filesystem

Filesystem utilities used by buildmanager and imageregistration: path normalisation, directory creation helpers, and checksum utilities.

nornir_shared.plot

Shared matplotlib plotting helpers (histograms, overlay images) used by imageregistration and buildmanager for diagnostic output.

Environment variables

NORNIR_LOG_ROOT

Root directory for all Nornir file logs. Required for persistent logging; omit to get console-only output. See Logging convention.

API reference: nornir_shared