logging

Provides a slog logger, configured for GCP Cloud Logging format and integrated with OpenTelemetry tracing. If the incoming context contains a trace, log messages will be recorded as events on the span, and log entries in GCP will include the "trace_id" field for improved observability.

The logger is also configured to support Error Reporting in GCP, automatically formatting error logs for reporting.

Install

go get github.com/dentech-floss/logging@v0.3.3

Usage

package example

import (
    "github.com/dentech-floss/metadata/pkg/metadata"
    "github.com/dentech-floss/logging/pkg/logging"
    "github.com/dentech-floss/revision/pkg/revision"
)

func main() {

    metadata := metadata.NewMetadata()

    logger := logging.NewLogger(
        &logging.LoggerConfig{
            ProjectID:    metadata.ProjectID,
            ServiceName: revision.ServiceName,
            MinLevel:    logging.InfoLevel,
        },
    )
    defer logger.Sync() // flushes buffer, if any

    patientGatewayServiceV1 := service.NewPatientGatewayServiceV1(logger) // inject it
}

package example

import (
    "github.com/dentech-floss/logging/pkg/logging"

    patient_gateway_service_v1 "go.buf.build/dentechse/go-grpc-gateway-openapiv2/dentechse/patient-api-gateway/api/patient/v1"
)

func (s *PatientGatewayServiceV1) FindAppointments(
    ctx context.Context,
    request *patient_gateway_service_v1.FindAppointmentsRequest,
) (*patient_gateway_service_v1.FindAppointmentsResponse, error) {

    // Ensure trace information + request is part of the log entries
    log := s.logger.With(logging.Proto("request", request))

    log.InfoContext(
        ctx,
        "Something something...",
        logging.String("something", something),
    )

    startTimeLocal, err := datetime.ISO8601StringToTime(request.StartTime)
    if err != nil {
        log.WarnContext(ctx, "The start time shall be in ISO 8601 format", logging.Error(err))
        return &patient_gateway_service_v1.FindAppointmentsResponse{},
            status.Errorf(codes.InvalidArgument, "The start time shall be in ISO 8601 format")
    }
}

import (
    "net/http"

    "github.com/dentech-floss/logging/pkg/logging"
    "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
)

// Example of wrapping an HTTP client's Transport with NewLoggingTransport
httpClient := &http.Client{}
httpClient.Transport = otelhttp.NewTransport(
    logging.NewLoggingTransport(
        httpClient.Transport,
        logger,
        &logging.LoggingOptions{
            DumpRequestFunc:  logging.DumpRequest,
            DumpResponseFunc: logging.DumpResponse,
        },
    ),
)