Log plugin RPC operations and connections

[vyasgun]

This PR also fixes linter warnings and deprecations

Logs visible in ~/.crc/crcd.log as follows:

grep RPC ~/.crc/crcd.log
time="2026-06-29T16:13:47+05:30" level=debug msg="() DBG | time=\"2026-06-29T16:13:47+05:30\" level=info msg=\"RPC connection accepted\" remote=\"127.0.0.1:35148\""
time="2026-06-29T16:13:47+05:30" level=debug msg="() DBG | time=\"2026-06-29T16:13:47+05:30\" level=debug msg=\"RPC server invocation\" machine=default operation=GetVersion"
time="2026-06-29T16:13:47+05:30" level=debug msg="() DBG | time=\"2026-06-29T16:13:47+05:30\" level=warning msg=\"RPC server invocation\" config_bytes=769 machine=default operation=SetConfigRaw"
time="2026-06-29T16:13:47+05:30" level=debug msg="() DBG | time=\"2026-06-29T16:13:47+05:30\" level=debug msg=\"RPC server invocation\" machine=crc operation=GetMachineName"
time="2026-06-29T16:13:47+05:30" level=debug msg="(crc) DBG | time=\"2026-06-29T16:13:47+05:30\" level=debug msg=\"RPC server invocation\" machine=crc operation=GetBundleName"
time="2026-06-29T16:13:47+05:30" level=debug msg="(crc) DBG | time=\"2026-06-29T16:13:47+05:30\" level=debug msg=\"RPC server invocation\" machine=crc operation=GetState"
time="2026-06-29T16:13:47+05:30" level=debug msg="(crc) DBG | time=\"2026-06-29T16:13:47+05:30\" level=info msg=\"RPC server invocation\" machine=crc operation=Close"

[coderabbitai]

Walkthrough

Structured logging is added to the RPC driver plugin layer: a loggingListener/loggingConn wrapper logs TCP connection accept and close events, and a new logRPC helper instruments all RPCServerDriver methods with logrus entries. The deadcode linter is removed from .golangci.yml, and two UpdateConfigRaw parameter names are changed to _.

Changes

RPC Driver Logging and Cleanup

Layer / File(s)	Summary
Unused parameter cleanup and linter removal .golangci.yml, drivers/fakedriver/fakedriver.go, libmachine/drivers/base.go	deadcode linter entry removed; UpdateConfigRaw []byte parameter renamed to _ in both BaseDriver and fakedriver.
Connection-level logging wrappers libmachine/drivers/plugin/register_driver.go	loggingListener and loggingConn types added to wrap the TCP listener; Accept() logs remote address on connect, Close() logs remote address and duration on disconnect; http.Serve updated to use the wrapper.
logRPC helper and per-method RPC logging libmachine/drivers/rpc/server_driver.go	logrus imported; logRPC helper added with recover()-guarded machine-name retrieval; all RPCServerDriver methods (Close, GetVersion, GetConfigRaw, UpdateConfigRaw, SetConfigRaw, Create, DriverName, GetIP, GetMachineName, GetBundleName, GetState, Kill, PreCreateCheck, Remove, Start, Stop, GetSharedDirs) instrumented with structured log entries.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐇 A rabbit hops through every RPC call,
Leaving logrus breadcrumbs along the hall.
Connections are timed from accept to close,
Dead code linter gone — one less thing that slows.
With _ where unused params used to hide,
The warren is tidy, logs logged with pride! 🪵

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: adding logging for plugin RPC operations and connections.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[cfergeau]

What was the gosec error?
You can replace

//nolint:gosec // localhost-only rpc server

with

//#nosec G703 localhost-only RPC server

with G703 replaced with the actual gosec error would provide more details

[cfergeau]

Is unused enabled by defaut?

For what it’s worth, this golangci-lint config is a v1 config while upstream has moved on to v2. Not sure it’s worth switching to v2 though…

[cfergeau]

How did you decide between the various log levels?