feat: rewrite logger on log/slog and add a structured logging API

[JoshVanL]

kit/logger was a thin wrapper over logrus. Call sites built their message eagerly with printf verbs, so the output carried no fields that could be filtered on beyond the fixed schema, and logrus allocated a fresh map per entry.

Replace the backend with log/slog and add a structured API alongside the existing one:

    log := logger.New("dapr.kit")
    log.Info("component loaded", "component", name)
    log.Error("failed to load component", logger.Err(err))

Output is byte-identical to logrus in both text and JSON. The log schema is documented public API and user log pipelines match on it, so the encoder reproduces logrus exactly: alphabetical field ordering, the "warning" level label, omission of an empty message in text but not in JSON, bare rendering of empty values, and HTML escaping in JSON. TestGoldenOutput pins all of it against output captured from logrus before it was removed.

Benchmarked against the previous logrus configuration, same machine, -count=3:

    text            1840 ns, 19 allocs,  953 B    810 ns, 3 allocs, 400 B
    json            2080 ns, 30 allocs, 1500 B   1070 ns, 4 allocs, 689 B
    disabled          21 ns,  1 alloc              20 ns, 1 alloc

The emitting path is roughly twice as fast for a sixth of the allocations. The disabled path is at parity, since both still box arguments at the call site; LogAttrs is the form that avoids it entirely at 0 allocations.

On the API:

• Log cannot implement Logger, because the embedded slog methods take a leading message string andnds. Use (*Log).Legacy() where a Logger is required.
• logger.FromLogger(Logger) This is the migration path for code that receives a Logger through a signature that cannot change, notablnstructor.
• Only the printf methods are marked Deprecated. The Logger interface and NewLogger are not, becrameter types for the duration of the migration, and deprecating them would flag thousands of legitimate us
• Configuration is per logger name and shared between the Logger and the Log of that name, matching each name owned its own logrus instance. A component setting its level from metadata therefore does noole process.

Two existing bugs are fixed

• EnableJSONOutput rebuilt t a second call silently dropped app_id and any fields added with WithFields.
• Loggers created after Applilt-in defaults of text output at info level instead of the configured options.

Also converts kit's own call sites to the structured API, drops the logrus dependency, configurease keys and
reject the reserved schema keys, and fixes a depguard rule that denied github.com/Sirupsen/logrus, since the
project was renamed, so it had never matched anything.

[Copilot]

Pull request overview

Replaces the logrus-backed logger with log/slog, adds structured logging, and preserves the existing Dapr log schema.

Changes:

• Adds structured logging, adapters, dynamic configuration, and compatibility encoding.
• Migrates internal call sites to structured attributes.
• Adds tests, benchmarks, lint rules, and removes logrus.

Reviewed changes

Copilot reviewed 26 out of 28 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
.golangci.yml	Configures slog linting and logrus bans.
concurrency/closer.go	Migrates shutdown logging.
concurrency/dir/dir.go	Migrates directory operation logging.
concurrency/dir/switch_unix.go	Migrates Unix switch logging.
crypto/spiffe/spiffe.go	Adds structured SPIFFE logging.
crypto/spiffe/trustanchors/file/file.go	Migrates trust-anchor logging.
errors/errors.go	Migrates error-detail logging.
go.mod	Removes logrus dependency.
go.sum	Refreshes dependency checksums.
jwkscache/cache.go	Migrates JWKS cache logging.
logger/attrs.go	Adds standard structured attributes.
logger/bench_test.go	Adds logger benchmarks.
logger/bridge.go	Adapts third-party legacy loggers.
logger/dapr_logger.go	Reimplements legacy API with slog.
logger/dapr_logger_test.go	Updates legacy logger tests.
logger/golden_capture_test.go	Pins output compatibility.
logger/handler.go	Implements custom schema encoders.
logger/levels.go	Maps Dapr and slog levels.
logger/log.go	Adds the structured logging API.
logger/log_test.go	Tests structured logging behavior.
logger/logger.go	Adds shared named configuration.
logger/nop_logger.go	Exposes a no-op logger.
logger/options.go	Applies persistent runtime configuration.
logger/options_test.go	Tests defaults and file output.
logger/state.go	Stores concurrent logger state.
signals/signals.go	Migrates shutdown signal logging.
signals/signals_posix.go	Migrates restart signal logging.

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[mikeee]

extraneous file committed

[mikeee]

foo

[m3nax]

Afternoon @JoshVanL, I've opened a small PR that adds support for registering additional handlers alongside the primary one. The idea is to make OTLP log export easier to plug in later on.

PR: JoshVanL#1

Let me know if this approach makes sense and whether it could be merged into your existing work.