Request logging interceptor

createLoggerInterceptor() is not part of the default chain. Add it when you need request, response and duration records for RPCs. Health checks are skipped by default:

import { createServer } from '@connectum/core';
import { createDefaultInterceptors, createLoggerInterceptor } from '@connectum/interceptors';

const server = createServer({
  services: [routes],
  interceptors: [
    ...createDefaultInterceptors(),
    createLoggerInterceptor({
      level: 'info',
      skipHealthCheck: true,
      includeTransport: true,
      includeBodies: false,
    }),
  ],
});

level defaults to debug, skipHealthCheck to true, and both includeTransport and includeBodies to false.

skipHealthCheck matches grpc.health as whole package segments, including grpc.health.v1.Health and a prefixed acme.grpc.health.v1.Probe. It does not skip acme.grpc.healthcare.v1.Svc, whose longer segment only contains the text.

skipHealthCheck, includeTransport and includeBodies must be booleans. level must be "debug", "info", "warn" or "error", and a supplied logger must be a function. Wrong types throw TypeError; an unsupported string level throws RangeError. These checks run at construction.

What a call writes

RPC /greeter.v1.GreeterService/SayHello request
RPC /greeter.v1.GreeterService/SayHello response
RPC /greeter.v1.GreeterService/SayHello completed in 1.84ms

A failing call writes RPC <path> failed with <Code> before completion. The code is the Connect code name, or Unknown for other errors; the original error reaches the caller unchanged. Streams log STREAM <path> request and STREAM <path> response for each message. Their duration covers the whole stream until it is fully read, fails or is closed early with break or return().

Transport tags

With includeTransport: true, each line adds [in-process] for server.localClient() and createLocalTransport() calls, or [http] for other calls, immediately after RPC/STREAM:

RPC [in-process] /greeter.v1.GreeterService/SayHello request
RPC [http] /greeter.v1.GreeterService/SayHello completed in 1.84ms

The tag comes from an internal request marker and is telemetry only. Never use it to authorize a call; use req.service.typeName and req.method.name. With the option disabled, records have no transport tag.

Message bodies are opt-in

By default no request or response body reaches the logger function. Bodies can contain credentials, tokens and personal data; logs often outlive the call and have more readers.

With includeBodies: true, unary calls pass their request/response message as an extra argument. Streams pass each request message and the JSON form of each response message:

createLoggerInterceptor({ includeBodies: true });
// logger('RPC /greeter.v1.GreeterService/SayHello request', { name: 'Ada' })

Enable this only when logs are protected as carefully as the traffic. See the migration guide.

Logging failures do not replace RPC results

If the supplied logger throws or rejects, the RPC still returns its response or original error. The first logging failure is reported once on the console; later failures are dropped. A streamed message that cannot be converted to JSON is logged as a marker and the stream continues.

See LoggerOptions. For structured application logging and exporters, use Observability logging.