Use TagTransformer for ConsoleExporter 💻

src/OpenTelemetry.Exporter.Console/CHANGELOG.md

@@ -2,6 +2,21 @@
 
 ## Unreleased
 
+* Improve the conversion and formatting of attribute values.
+  The list of data types that must be supported per the
+  [OpenTelemetry specification](https://github.com/open-telemetry/opentelemetry-specification/tree/main/specification/common#attribute)
+  is more narrow than what the .NET OpenTelemetry SDK supports. Numeric
+  [built-in value types](https://docs.microsoft.com/dotnet/csharp/language-reference/builtin-types/built-in-types)
+  are supported by converting to a `long` or `double` as appropriate except for
+  numeric types that could cause overflow (`ulong`) or rounding (`decimal`)
+  which are converted to strings. Non-numeric built-in types - `string`,
+  `char`, `bool` are supported. All other types are converted to a `string`.
+  Array values are also supported.
+  ([#3311](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3311))
+* Fix conversion of array-valued attributes. They were previously
+  converted to a string like "System.String[]".
+  ([#3311](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3311))
+
 ## 1.3.0-beta.2
 
 Released 2022-May-16

src/OpenTelemetry.Exporter.Console/ConsoleActivityExporter.cs

@@ -14,7 +14,6 @@
 // limitations under the License.
 // </copyright>
 
-using System;
 using System.Diagnostics;
 using System.Linq;
 using OpenTelemetry.Resources;
@@ -71,13 +70,10 @@ public override ExportResult Export(in Batch<Activity> batch)
                             continue;
                         }
 
-                        if (tag.Value is not Array array)
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(tag, out var result))
                         {
-                            this.WriteLine($"    {tag.Key}: {tag.Value}");
-                            continue;
+                            this.WriteLine($"    {result}");
                         }
-
-                        this.WriteLine($"    {tag.Key}: [{string.Join(", ", array.Cast<object>())}]");
                     }
                 }
 
@@ -106,7 +102,10 @@ public override ExportResult Export(in Batch<Activity> batch)
                         this.WriteLine($"    {activityEvent.Name} [{activityEvent.Timestamp}]");
                         foreach (var attribute in activityEvent.Tags)
                         {
-                            this.WriteLine($"        {attribute.Key}: {attribute.Value}");
+                            if (ConsoleTagTransformer.Instance.TryTransformTag(attribute, out var result))
+                            {
+                                this.WriteLine($"        {result}");
+                            }
                         }
                     }
                 }
@@ -117,6 +116,13 @@ public override ExportResult Export(in Batch<Activity> batch)
                     foreach (var activityLink in activity.Links)
                     {
                         this.WriteLine($"    {activityLink.Context.TraceId} {activityLink.Context.SpanId}");
+                        foreach (var attribute in activityLink.Tags)
+                        {
+                            if (ConsoleTagTransformer.Instance.TryTransformTag(attribute, out var result))
+                            {
+                                this.WriteLine($"        {result}");
+                            }
+                        }
                     }
                 }
 
@@ -126,7 +132,10 @@ public override ExportResult Export(in Batch<Activity> batch)
                     this.WriteLine("Resource associated with Activity:");
                     foreach (var resourceAttribute in resource.Attributes)
                     {
-                        this.WriteLine($"    {resourceAttribute.Key}: {resourceAttribute.Value}");
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(resourceAttribute, out var result))
+                        {
+                            this.WriteLine($"    {result}");
+                        }
                     }
                 }
 

src/OpenTelemetry.Exporter.Console/ConsoleLogRecordExporter.cs

@@ -62,13 +62,13 @@ public override ExportResult Export(in Batch<LogRecord> batch)
                         // Special casing {OriginalFormat}
                         // See https://github.com/open-telemetry/opentelemetry-dotnet/pull/3182
                         // for explanation.
-                        if (logRecord.StateValues[i].Key.Equals("{OriginalFormat}"))
-                        {
-                            this.WriteLine($"{string.Empty,-4}{"OriginalFormat (a.k.a. Body)",-RightPaddingLength}{logRecord.StateValues[i].Value}");
-                        }
-                        else
+                        var valueToTransform = logRecord.StateValues[i].Key.Equals("{OriginalValue}")
+                            ? new KeyValuePair<string, object>("OriginalFormat (a.k.a Body)", logRecord.StateValues[i].Value)
+                            : logRecord.StateValues[i];
+
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(valueToTransform, out var result))
                         {
-                            this.WriteLine($"{string.Empty,-4}{logRecord.StateValues[i].Key,-RightPaddingLength}{logRecord.StateValues[i].Value}");
+                            this.WriteLine($"{string.Empty,-4}{result}");
                         }
                     }
                 }
@@ -100,7 +100,10 @@ void ProcessScope(LogRecordScope scope, ConsoleLogRecordExporter exporter)
 
                     foreach (KeyValuePair<string, object> scopeItem in scope)
                     {
-                        exporter.WriteLine($"[Scope.{scopeDepth}]:{scopeItem.Key,-RightPaddingLength}{scopeItem.Value}");
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(scopeItem, out var result))
+                        {
+                            exporter.WriteLine($"[Scope.{scopeDepth}]:{result}");
+                        }
                     }
                 }
 
@@ -110,7 +113,10 @@ void ProcessScope(LogRecordScope scope, ConsoleLogRecordExporter exporter)
                     this.WriteLine("\nResource associated with LogRecord:");
                     foreach (var resourceAttribute in resource.Attributes)
                     {
-                        this.WriteLine($"{resourceAttribute.Key}: {resourceAttribute.Value}");
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(resourceAttribute, out var result))
+                        {
+                            this.WriteLine(result);
+                        }
                     }
                 }
 

src/OpenTelemetry.Exporter.Console/ConsoleMetricExporter.cs

@@ -80,10 +80,11 @@ public override ExportResult Export(in Batch<Metric> batch)
                     StringBuilder tagsBuilder = new StringBuilder();
                     foreach (var tag in metricPoint.Tags)
                     {
-                        tagsBuilder.Append(tag.Key);
-                        tagsBuilder.Append(':');
-                        tagsBuilder.Append(tag.Value);
-                        tagsBuilder.Append(' ');
+                        if (ConsoleTagTransformer.Instance.TryTransformTag(tag, out var result))
+                        {
+                            tagsBuilder.Append(result);
+                            tagsBuilder.Append(' ');
+                        }
                     }
 
                     var tags = tagsBuilder.ToString().TrimEnd();

src/OpenTelemetry.Exporter.Console/ConsoleTagTransformer.cs

@@ -0,0 +1,40 @@
+// <copyright file="ConsoleTagTransformer.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+using OpenTelemetry.Internal;
+
+namespace OpenTelemetry.Exporter;
+
+internal sealed class ConsoleTagTransformer : TagTransformer<string>
+{
+    private ConsoleTagTransformer()
+    {
+    }
+
+    public static ConsoleTagTransformer Instance { get; } = new();
+
+    protected override string TransformIntegralTag(string key, long value) => $"{key}: {value}";
+
+    protected override string TransformFloatingPointTag(string key, double value) => $"{key}: {value}";
+
+    protected override string TransformBooleanTag(string key, bool value) => $"{key}: {(value ? "true" : "false")}";
+
+    protected override string TransformStringTag(string key, string value) => $"{key}: {value}";
+
+    protected override string TransformArrayTag(string key, Array array)
+        => this.TransformStringTag(key, System.Text.Json.JsonSerializer.Serialize(array));
+}

src/OpenTelemetry.Exporter.Console/OpenTelemetry.Exporter.Console.csproj

@@ -18,13 +18,20 @@
     <RunApiCompat>false</RunApiCompat>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="System.Text.Json" Version="$(SystemTextJsonPkgVer)" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="$(RepoRoot)\src\OpenTelemetry\OpenTelemetry.csproj" />
   </ItemGroup>
 
   <ItemGroup>
+    <Compile Include="$(RepoRoot)\src\OpenTelemetry\Internal\OpenTelemetrySdkEventSource.cs" Link="Includes\OpenTelemetrySdkEventSource.cs" />
     <Compile Include="$(RepoRoot)\src\OpenTelemetry\Internal\PeriodicExportingMetricReaderHelper.cs" Link="Includes\PeriodicExportingMetricReaderHelper.cs" />
     <Compile Include="$(RepoRoot)\src\OpenTelemetry\Internal\ServiceProviderExtensions.cs" Link="Includes\ServiceProviderExtensions.cs" />
+    <Compile Include="$(RepoRoot)\src\OpenTelemetry\Internal\TagTransformer.cs" Link="Includes\TagTransformer.cs" />
+    <Compile Include="$(RepoRoot)\src\OpenTelemetry.Api\Internal\ExceptionExtensions.cs" Link="Includes\ExceptionExtensions.cs" />
     <Compile Include="$(RepoRoot)\src\OpenTelemetry.Api\Internal\Guard.cs" Link="Includes\Guard.cs" />
     <Compile Include="$(RepoRoot)\src\OpenTelemetry.Api\Internal\SpanAttributeConstants.cs" Link="Includes\SpanAttributeConstants.cs" />
   </ItemGroup>