README

Waffle Log Component

Release: 0.1.0-beta3  |  CHANGELOG.md PSR Compliance: PSR-3 (Psr\Log\AbstractLogger)

A strict, container-native logger that emits one JSON line per record onto a stream. Designed for Docker/Kubernetes deployments where stdout/stderr are the log sinks — no buffering, no per-process state, safe across FrankenPHP worker requests.

📦 Installation

composer require waffle-commons/log

🧱 Surface

🚀 Usage

StreamLogger exposes its configuration via PHP 8.5 asymmetric visibility (public private(set)) and readonly promoted properties:

use Waffle\Commons\Log\StreamLogger;
use Waffle\Commons\Log\Channel\LogChannel;

$logger = new StreamLogger(
    streamPath: 'php://stderr',
    channel: LogChannel::HTTP,
    permissions: 0o644,
);

$logger->info('Request handled', ['route' => '/users', 'status' => 200]);

The signature, verbatim from src/StreamLogger.php:

public function __construct(
    private(set) readonly string $streamPath = 'php://stderr',
    private(set) readonly string $channel = LogChannel::APP,
    private(set) readonly int $permissions = 0o644,
) { /* opens the stream, chmods if it's a regular file */ }

🪵 Output format

Every record is a single JSON object emitted with a trailing \n, suitable for Docker's JSON-file driver and for jq/grep pipelines:

{"time":"2026-05-16T10:42:01.123+00:00","level":"info","channel":"http","message":"Request handled","context":{"route":"/users","status":200}}

RFC 5424 / Monolog level constants (DEBUG=100 … EMERGENCY=600) are interpolated from Psr\Log\LogLevel — no custom level vocabulary.

🧷 Channels

LogChannel is a typed-constant container (intentionally not a backed enum, so it can be used as a property default):

final class LogChannel
{
    public const string APP = 'app';
    public const string CORE = 'core';
    public const string HTTP = 'http';
    public const string SECURITY = 'sec';
    public const string AUDIT = 'audit';
}

🛡️ Worker-mode safety

• Stream is opened in the constructor and closed in __destruct(), preventing file-descriptor leaks across long-running workers.
• No per-call buffering; each log() call writes immediately.
• No static state. Multiple StreamLogger instances can co-exist (one per channel, for example).

🧭 Architectural boundary (mago guard)

An active dependency perimeter is enforced on every CI run by vendor/bin/mago guard (bundled into composer mago; zero baselines). The rules live in mago.toml under [guard.perimeter] — a forbidden use statement fails the build, not a reviewer.

Production code under Waffle\Commons\Log may depend only on:

• Waffle\Commons\Log\** — itself
• Waffle\Commons\Contracts\** — the shared contracts package, the only Waffle dependency permitted
• Psr\** — PSR interfaces (PSR-3)
• @global + Psl\** — PHP core and the PHP Standard Library

Test code under WaffleTests\Commons\Log is unrestricted (@all). Structural rules are guarded too: interfaces must be named *Interface, Exception\** classes must end in *Exception, and any Enum\** namespace may hold only enum declarations.

Contract-first, component-agnostic by construction: components compose through waffle-commons/contracts, never directly through one another.

🧪 Testing

docker exec -w /waffle-commons/log waffle-dev composer tests

📄 License

MIT — see LICENSE.md.