[OpenTelemetry] Add traces to init command (#2665)

Signed-off-by: James Humphries <james@james-humphries.co.uk>
Signed-off-by: Christian Mesh <christianmesh1@gmail.com>
Co-authored-by: Christian Mesh <christianmesh1@gmail.com>

internal/tracing/utils.go

@@ -0,0 +1,121 @@
+// Copyright (c) The OpenTofu Authors
+// SPDX-License-Identifier: MPL-2.0
+// Copyright (c) 2023 HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package tracing
+
+import (
+	"context"
+	"errors"
+	"log"
+	"runtime"
+	"strings"
+	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+
+	"go.opentelemetry.io/otel/trace"
+
+	"github.com/opentofu/opentofu/internal/tfdiags"
+)
+
+func Tracer() trace.Tracer {
+	if !isTracingEnabled {
+		return otel.Tracer("")
+	}
+
+	pc, _, _, ok := runtime.Caller(1)
+	if !ok || runtime.FuncForPC(pc) == nil {
+		return otel.Tracer("")
+	}
+
+	// We use the import path of the caller function as the tracer name.
+	return otel.GetTracerProvider().Tracer(extractImportPath(runtime.FuncForPC(pc).Name()))
+}
+
+// SetSpanError sets the error or diagnostic information on the span.
+// It accepts an error, a string, or a diagnostics object.
+// It also sets the span status to Error and records the error or message.
+func SetSpanError(span trace.Span, input any) {
+	if span == nil || input == nil {
+		return
+	}
+
+	switch v := input.(type) {
+	case error:
+		if v != nil {
+			span.SetStatus(codes.Error, v.Error())
+			span.RecordError(v)
+		}
+	case string:
+		if v != "" {
+			span.SetStatus(codes.Error, v)
+			span.RecordError(errors.New(v))
+		}
+	case tfdiags.Diagnostics: // Assuming Diagnostics is a custom type you have defined elsewhere
+		if v.HasErrors() { // Assuming IsEmpty() checks if the diagnostics object has content
+			span.SetStatus(codes.Error, v.Err().Error())
+			span.RecordError(v.Err())
+		}
+	default:
+		// Handle unsupported types gracefully
+		// TODO: Discuss if this should panic?
+		span.SetStatus(codes.Error, "ERROR: unsupported input type for SetSpanError.")
+		span.AddEvent("ERROR: unsupported input type for SetSpanError")
+	}
+}
+
+// ForceFlush ensures that all spans are exported to the collector before
+// the application terminates. This is particularly important for CLI
+// applications where the process exits immediately after the operation.
+//
+// This should be called before the application terminates to ensure
+// all spans are exported properly.
+func ForceFlush(timeout time.Duration) {
+	if !isTracingEnabled {
+		return
+	}
+
+	provider, ok := otel.GetTracerProvider().(*sdktrace.TracerProvider)
+	if !ok {
+		log.Printf("[DEBUG] OpenTelemetry: tracer provider is not an SDK provider, can't force flush")
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+
+	log.Printf("[DEBUG] OpenTelemetry: flushing spans")
+	if err := provider.ForceFlush(ctx); err != nil {
+		log.Printf("[WARN] OpenTelemetry: error flushing spans: %v", err)
+	}
+}
+
+// extractImportPath extracts the import path from a full function name.
+// the function names returned by runtime.FuncForPC(pc).Name() can be in the following formats
+//
+//	main.(*MyType).MyMethod
+//	github.com/you/pkg.(*SomeType).Method-fm
+//	github.com/you/pkg.functionName
+func extractImportPath(fullName string) string {
+	lastSlash := strings.LastIndex(fullName, "/")
+	if lastSlash == -1 {
+		// When there is no slash, then use everything before the first dot
+		if dot := strings.Index(fullName, "."); dot != -1 {
+			return fullName[:dot]
+		}
+		log.Printf("[WARN] unable to extract import path from function name: %q. Tracing may be incomplete. This is a bug in OpenTofu, please report it.", fullName)
+		return "unknown"
+	}
+
+	dotAfterSlash := strings.Index(fullName[lastSlash:], ".")
+	if dotAfterSlash == -1 {
+		log.Printf("[WARN] unable to extract import path from function name: %q. Tracing may be incomplete. This is a bug in OpenTofu, please report it.", fullName)
+		return "unknown"
+	}
+
+	return fullName[:lastSlash+dotAfterSlash]
+}