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Logging

p4net uses the standard-library logging module under a p4net root logger. Every internal module logs under its dotted path — e.g. p4net.network.orchestrator, p4net.runtime.bmv2, p4net.compiler.p4c — so consumers can filter or redirect any subsystem independently.

Namespace

The p4net.* logger namespace is stable: names will not change in 1.x. Concretely:

  • logging.getLogger("p4net.network").setLevel(logging.DEBUG) works in 1.0 and will keep working through every 1.x release.
  • New submodule names may be added (e.g. p4net.network.cleanup), but existing ones won't be renamed or removed without a major version bump.

Levels

Level What you'll see
ERROR Failures the library couldn't handle. Usually paired with a raised exception.
WARNING Unexpected but handled. The library recovered or worked around something.
INFO Lifecycle events: Network.start / stop, BMv2 spawn, gRPC client connect, primary acquired.
DEBUG Detailed decisions: compiler cache hit/miss, retry attempts, election ID, low-level netlink calls.

Log levels for specific events are not part of the stable contract — we may downgrade INFO events to DEBUG if they prove too noisy in real usage, or vice versa. The level taxonomy itself is stable; which-event-uses-which is not.

Log message text is not stable. Don't grep production logs for specific strings; use the level and logger name instead.

CLI verbosity

The p4net console script accepts:

  • no flag → default level WARNING (only problems show up)
  • -v / --verbose → INFO
  • -vv → DEBUG

Higher counts (-vvv, …) also resolve to DEBUG; there is no level quieter than the standard WARNING.

Programmatic configuration

In your own scripts, configure logging before importing or instantiating p4net components — basicConfig only takes effect on the first call:

import logging

logging.basicConfig(level=logging.INFO)

# Optional: turn one subsystem up to DEBUG while keeping the rest at INFO.
logging.getLogger("p4net.runtime").setLevel(logging.DEBUG)

For more elaborate configuration (file handlers, JSON formatters, forwarding to syslog), build a logging.config.dictConfig payload the same way you would for any other library.