reorganize exporters and simplify their use

pkg/exporters/console_exporter/console_exporter.go

@@ -0,0 +1,125 @@
+package console_exporter
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"git.ma-al.com/gora_filip/pkg/level"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/trace"
+)
+
+type TraceFormatter interface {
+	FormatSpans(spans []trace.ReadOnlySpan, removeFields []attribute.Key, verbosityLevel level.SeverityLevel, addTraceId bool, onlyErrors bool) (string, error)
+}
+
+// Configuration for the exporter.
+//
+// Most of options are passed to the formatter.
+type ExporterOptions struct {
+	// Try to parse filters from an environment variable with a name provided by this field.
+	// Result will only by applied to unset options. NOT IMPLEMENTED!
+	FilterFromEnvVar *string
+	// Filter the output based on the [level.SeverityLevel].
+	FilterOnLevel *level.SeverityLevel
+	// Fields that should be removed from the output.
+	FilterOutFields []attribute.Key
+	// Print only trace events instead of whole traces.
+	EmitEventsOnly bool
+	// Add trace id to output
+	EmitTraceId bool
+	// Print output only when an error is found
+	EmitOnlyOnError bool
+	// Used only when `EmitEventsOnly` is set to true.
+	TraceFormatter *TraceFormatter
+}
+
+type Exporter struct {
+	lvl            level.SeverityLevel
+	removedFields  []attribute.Key
+	addTraceId     bool
+	onlyErrs       bool
+	traceFormatter TraceFormatter
+	printerMu      sync.Mutex
+	stoppedMu      sync.RWMutex
+	stopped        bool
+}
+
+// NOTE: The configuration might change in future releases
+func DefaultConsoleExporter() trace.SpanExporter {
+	lvl := level.DEBUG
+	fmt := NewEventsOnlyFormatter()
+	return NewExporter(ExporterOptions{
+		FilterFromEnvVar: nil,
+		FilterOnLevel:    &lvl,
+		FilterOutFields:  []attribute.Key{},
+		EmitEventsOnly:   false,
+		EmitTraceId:      true,
+		EmitOnlyOnError:  false,
+		TraceFormatter:   &fmt,
+	})
+}
+
+func NewExporter(opts ExporterOptions) trace.SpanExporter {
+	var formatter TraceFormatter
+	var lvl level.SeverityLevel
+
+	if opts.TraceFormatter != nil {
+		formatter = *opts.TraceFormatter
+	} else {
+		formatter = TraceFormatter(&EventsOnlyFormatter{})
+	}
+	if opts.FilterOnLevel != nil {
+		lvl = *opts.FilterOnLevel
+	} else {
+		lvl = level.TRACE
+	}
+
+	return &Exporter{
+		traceFormatter: formatter,
+		removedFields:  opts.FilterOutFields,
+		addTraceId:     opts.EmitTraceId,
+		onlyErrs:       opts.EmitOnlyOnError,
+		lvl:            lvl,
+	}
+}
+
+// Implements [trace.SpanExporter]
+func (e *Exporter) ExportSpans(ctx context.Context, spans []trace.ReadOnlySpan) error {
+	e.stoppedMu.RLock()
+	stopped := e.stopped
+	e.stoppedMu.RUnlock()
+	if stopped {
+		return nil
+	}
+	if len(spans) == 0 {
+		return nil
+	}
+
+	e.printerMu.Lock()
+	defer e.printerMu.Unlock()
+	printLine, err := e.traceFormatter.FormatSpans(spans, e.removedFields, e.lvl, e.addTraceId, e.onlyErrs)
+	if err != nil {
+		fmt.Printf("FAILED TO FORMAT A TRACE WITH ERR: %#v\n", err)
+	}
+	if len(printLine) > 0 {
+		fmt.Println(printLine)
+	}
+
+	return nil
+}
+
+// Implements [trace.SpanExporter]
+func (e *Exporter) Shutdown(ctx context.Context) error {
+	e.stoppedMu.Lock()
+	e.stopped = true
+	e.stoppedMu.Unlock()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+	return nil
+}

pkg/exporters/console_exporter/event_only_formatter.go

@@ -0,0 +1,97 @@
+package console_exporter
+
+import (
+	"fmt"
+	"slices"
+
+	"git.ma-al.com/gora_filip/pkg/attr"
+	"git.ma-al.com/gora_filip/pkg/code_location"
+	"git.ma-al.com/gora_filip/pkg/console_fmt"
+	"git.ma-al.com/gora_filip/pkg/level"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/sdk/trace/tracetest"
+	"go.opentelemetry.io/otel/semconv/v1.25.0"
+)
+
+func NewEventsOnlyFormatter() TraceFormatter {
+	return &EventsOnlyFormatter{}
+}
+
+// A formatter that will print only events using a multiline format with colors.
+// It uses attributes from the [attr] and [semconv] packages.
+type EventsOnlyFormatter struct{}
+
+func (f *EventsOnlyFormatter) FormatSpans(spans []trace.ReadOnlySpan, removeFields []attribute.Key, verbosityLevel level.SeverityLevel, addTraceId bool, onlyOnError bool) (string, error) {
+	stubs := tracetest.SpanStubsFromReadOnlySpans(spans)
+
+	var formattedSpanString string
+
+	for i := range stubs {
+		stub := &stubs[i]
+		for j := range stub.Events {
+			var attributes map[attribute.Key]string = make(map[attribute.Key]string, 0)
+			var msg string
+			var lvl level.SeverityLevel
+			var isErr bool
+			var location code_location.CodeLocation
+
+			for _, attrKV := range stub.Attributes {
+				if _, exists := attributes[attrKV.Key]; !exists {
+					attributes[attrKV.Key] = attrKV.Value.AsString()
+				}
+			}
+
+			for _, attrKV := range stub.Events[j].Attributes {
+				switch attrKV.Key {
+				case attr.LogMessageLongKey:
+					msg = attrKV.Value.AsString()
+				case attr.LogMessageShortKey:
+					if len(msg) == 0 {
+						msg = attrKV.Value.AsString()
+					}
+				case attr.SeverityLevelKey:
+					lvl = level.FromString(attrKV.Value.AsString())
+				case semconv.CodeFilepathKey:
+					location.FilePath = attrKV.Value.AsString()
+				case semconv.CodeLineNumberKey:
+					location.LineNumber = int(attrKV.Value.AsInt64())
+				case semconv.CodeColumnKey:
+					location.ColumnNumber = int(attrKV.Value.AsInt64())
+				case semconv.ExceptionMessageKey:
+					attributes[attrKV.Key] = attrKV.Value.AsString()
+					isErr = true
+				default:
+					if !slices.Contains(removeFields, attrKV.Key) && len(attrKV.Key) > 0 {
+						attributes[attrKV.Key] = attrKV.Value.AsString()
+					}
+				}
+			}
+			if len(msg) == 0 {
+				msg = stub.Name
+			}
+			if addTraceId {
+				attributes[attribute.Key("trace_id")] = stub.SpanContext.TraceID().String()
+			}
+			if len(location.FilePath) > 0 {
+				attributes["code.location"] = fmt.Sprintf("%s:%d:%d", location.FilePath, location.LineNumber, location.ColumnNumber)
+			}
+
+			if !(!isErr && onlyOnError) && lvl <= verbosityLevel {
+				attrs := ""
+				for k, v := range attributes {
+					attrs += fmt.Sprintf("\t%s%s%s = %s\n", console_fmt.ColorBold, k, console_fmt.ColorReset, v)
+				}
+
+				formattedSpanString += fmt.Sprintf(
+					"%s %s\n%s",
+					fmt.Sprintf("%s[%s]", console_fmt.SeverityLevelToColor(lvl), lvl.String()),
+					fmt.Sprintf("%s%s", msg, console_fmt.ColorReset),
+					attrs,
+				)
+			}
+		}
+	}
+
+	return formattedSpanString, nil
+}