Added OpenTelemetryEnvironment

src/Serilog.Sinks.OpenTelemetry/OpenTelemetryLoggerConfigurationExtensions.cs

@@ -12,13 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-using System.Net.Http;
-using Serilog.Configuration;
-using Serilog.Sinks.OpenTelemetry;
-using Serilog.Sinks.OpenTelemetry.Exporters;
 using Serilog.Collections;
+using Serilog.Configuration;
 using Serilog.Core;
 using Serilog.Events;
+using Serilog.Sinks.OpenTelemetry;
+using Serilog.Sinks.OpenTelemetry.Configuration;
+using Serilog.Sinks.OpenTelemetry.Exporters;
+using System.Net.Http;
 
 namespace Serilog;
 
@@ -33,23 +34,30 @@ public static class OpenTelemetryLoggerConfigurationExtensions
 #else
         null;
 #endif
-    
+
     /// <summary>
     /// Send log events to an OTLP exporter.
     /// </summary>
     /// <param name="loggerSinkConfiguration">
     /// The `WriteTo` configuration object.
     /// </param>
     /// <param name="configure">The configuration callback.</param>
+    /// <param name="ignoreEnvironment">If false the configuration will be overridden with values from <see href="https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/">OTLP Exporter Configuration environment variables</see>.</param>
     public static LoggerConfiguration OpenTelemetry(
         this LoggerSinkConfiguration loggerSinkConfiguration,
-        Action<BatchedOpenTelemetrySinkOptions> configure)
+        Action<BatchedOpenTelemetrySinkOptions> configure,
+        bool ignoreEnvironment = false)
     {
         if (configure == null) throw new ArgumentNullException(nameof(configure));
 
         var options = new BatchedOpenTelemetrySinkOptions();
         configure(options);
 
+        if (!ignoreEnvironment)
+        {
+            OpenTelemetryEnvironment.Configure(options, Environment.GetEnvironmentVariable);
+        }
+
         var exporter = Exporter.Create(
             endpoint: options.Endpoint,
             protocol: options.Protocol,
@@ -117,7 +125,7 @@ public static LoggerConfiguration OpenTelemetry(
             resourceAttributes?.AddTo(options.ResourceAttributes);
         });
     }
-    
+
     /// <summary>
     /// Audit to an OTLP exporter, waiting for each event to be acknowledged, and propagating errors to the caller.
     /// </summary>

src/Serilog.Sinks.OpenTelemetry/Serilog.Sinks.OpenTelemetry.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
     <PropertyGroup>
         <Description>This Serilog sink transforms Serilog events into OpenTelemetry
             logs and sends them to an OTLP (gRPC or HTTP) endpoint.</Description>

src/Serilog.Sinks.OpenTelemetry/Sinks/OpenTelemetry/Configuration/OpenTelemetryEnvironment.cs

@@ -0,0 +1,51 @@
+namespace Serilog.Sinks.OpenTelemetry.Configuration;
+
+static class OpenTelemetryEnvironment
+{
+    private const string PROTOCOL = "OTEL_EXPORTER_OTLP_PROTOCOL";
+    private const string ENDPOINT = "OTEL_EXPORTER_OTLP_ENDPOINT";
+    private const string HEADERS = "OTEL_EXPORTER_OTLP_HEADERS";
+    private const string RESOURCE_ATTRIBUTES = "OTEL_RESOURCE_ATTRIBUTES";
+
+    public static void Configure(BatchedOpenTelemetrySinkOptions options, Func<string, string?> getEnvironmentVariable)
+    {
+        options.Protocol = getEnvironmentVariable(PROTOCOL) switch
+        {
+            "http/protobuf" => OtlpProtocol.HttpProtobuf,
+            "grpc" => OtlpProtocol.Grpc,
+            _ => options.Protocol
+        };
+
+        if (getEnvironmentVariable(ENDPOINT) is { Length: > 1 } endpoint)
+            options.Endpoint = endpoint;
+
+        if (options.Protocol == OtlpProtocol.HttpProtobuf && !string.IsNullOrEmpty(options.Endpoint) && !options.Endpoint.EndsWith("/v1/logs"))
+            options.Endpoint = $"{options.Endpoint}/v1/logs";
+
+        FillHeadersIfPresent(getEnvironmentVariable(HEADERS), options.Headers);
+
+        FillHeadersResourceAttributesIfPresent(getEnvironmentVariable(RESOURCE_ATTRIBUTES), options.ResourceAttributes);
+    }
+
+    private static void FillHeadersIfPresent(string? config, IDictionary<string, string> headers)
+    {
+        foreach (var part in config?.Split(',') ?? [])
+        {
+            if (part.Split('=') is { Length: 2 } parts)
+                headers.Add(parts[0], parts[1]);
+            else
+                throw new InvalidOperationException($"Invalid header format: {part} in {HEADERS} environment variable.");
+        }
+    }
+
+    private static void FillHeadersResourceAttributesIfPresent(string? config, IDictionary<string, object> resourceAttributes)
+    {
+        foreach (var part in config?.Split(',') ?? [])
+        {
+            if (part.Split('=') is { Length: 2 } parts)
+                resourceAttributes.Add(parts[0], parts[1]);
+            else
+                throw new InvalidOperationException($"Invalid resourceAttributes format: {part} in {RESOURCE_ATTRIBUTES} environment variable.");
+        }
+    }
+}

test/Serilog.Sinks.OpenTelemetry.Tests/OpenTelemetryEnvironmentTests.cs

@@ -0,0 +1,95 @@
+using Serilog.Sinks.OpenTelemetry.Configuration;
+using Xunit;
+
+namespace Serilog.Sinks.OpenTelemetry.Tests;
+
+public class OpenTelemetryEnvironmentTests
+{
+    [Fact]
+    public void ConfigureFillOptionsWithEnvironmentVariablesValues()
+    {
+        BatchedOpenTelemetrySinkOptions options = new();
+        var endpoint = "http://localhost";
+        var protocol = OtlpProtocol.Grpc;
+        var headers = "header1=1,header2=2";
+        var resourceAttributes = "name1=1,name2=2";
+
+        OpenTelemetryEnvironment.Configure(options, GetEnvVar);
+
+        Assert.Equal(endpoint, options.Endpoint);
+        Assert.Equal(protocol, options.Protocol);
+        Assert.Collection(options.Headers,
+            e => Assert.Equal(("header1", "1"), (e.Key, e.Value)),
+            e => Assert.Equal(("header2", "2"), (e.Key, e.Value)));
+        Assert.Collection(options.ResourceAttributes,
+            e => Assert.Equal(("name1", "1"), (e.Key, e.Value)),
+            e => Assert.Equal(("name2", "2"), (e.Key, e.Value)));
+
+        string? GetEnvVar(string name)
+             => name switch
+             {
+                 "OTEL_EXPORTER_OTLP_ENDPOINT" => endpoint,
+                 "OTEL_EXPORTER_OTLP_HEADERS" => headers,
+                 "OTEL_RESOURCE_ATTRIBUTES" => resourceAttributes,
+                 "OTEL_EXPORTER_OTLP_PROTOCOL" => "grpc",
+                 _ => null
+             };
+    }
+
+    [Fact]
+    public void ConfigureAppendPathToEndpointIfProtocolIsHttpProtobufAndEndpointDoesntEndsWithProperValue()
+    {
+        BatchedOpenTelemetrySinkOptions options = new();
+        var endpoint = "http://localhost";
+        var protocol = OtlpProtocol.HttpProtobuf;
+
+        OpenTelemetryEnvironment.Configure(options, GetEnvVar);
+
+        Assert.Equal($"{endpoint}/v1/logs", options.Endpoint);
+        Assert.Equal(protocol, options.Protocol);
+
+        string? GetEnvVar(string name)
+             => name switch
+             {
+                 "OTEL_EXPORTER_OTLP_ENDPOINT" => endpoint,
+                 "OTEL_EXPORTER_OTLP_PROTOCOL" => "http/protobuf",
+                 _ => null
+             };
+    }
+
+    [Fact]
+    public void ConfigureThrowsIfHeaderEnvIsInvalidFormat()
+    {
+        BatchedOpenTelemetrySinkOptions options = new();
+        var headers = "header1";
+
+        var exception = Assert.Throws<InvalidOperationException>(() => OpenTelemetryEnvironment.Configure(options, GetEnvVar));
+
+        Assert.Equal("Invalid header format: header1 in OTEL_EXPORTER_OTLP_HEADERS environment variable.", exception.Message);
+
+        string? GetEnvVar(string name)
+             => name switch
+             {
+                 "OTEL_EXPORTER_OTLP_HEADERS" => headers,
+                 _ => null
+             };
+    }
+
+    [Fact]
+    public void ConfigureThrowsIfResourceAttributesEnvIsInvalidFormat()
+    {
+        BatchedOpenTelemetrySinkOptions options = new();
+        var resourceAttributes = "resource1";
+
+        var exception = Assert.Throws<InvalidOperationException>(() => OpenTelemetryEnvironment.Configure(options, GetEnvVar));
+
+        Assert.Equal("Invalid resourceAttributes format: resource1 in OTEL_RESOURCE_ATTRIBUTES environment variable.", exception.Message);
+
+        string? GetEnvVar(string name)
+             => name switch
+             {
+                 "OTEL_RESOURCE_ATTRIBUTES" => resourceAttributes,
+                 _ => null
+             };
+    }
+}

test/Serilog.Sinks.OpenTelemetry.Tests/PublicApiVisibilityTests.approved.txt

@@ -3,7 +3,7 @@
     public static class OpenTelemetryLoggerConfigurationExtensions
     {
         public static Serilog.LoggerConfiguration OpenTelemetry(this Serilog.Configuration.LoggerAuditSinkConfiguration loggerAuditSinkConfiguration, System.Action<Serilog.Sinks.OpenTelemetry.OpenTelemetrySinkOptions> configure) { }
-        public static Serilog.LoggerConfiguration OpenTelemetry(this Serilog.Configuration.LoggerSinkConfiguration loggerSinkConfiguration, System.Action<Serilog.Sinks.OpenTelemetry.BatchedOpenTelemetrySinkOptions> configure) { }
+        public static Serilog.LoggerConfiguration OpenTelemetry(this Serilog.Configuration.LoggerSinkConfiguration loggerSinkConfiguration, System.Action<Serilog.Sinks.OpenTelemetry.BatchedOpenTelemetrySinkOptions> configure, bool ignoreEnvironment = false) { }
         public static Serilog.LoggerConfiguration OpenTelemetry(this Serilog.Configuration.LoggerAuditSinkConfiguration loggerAuditSinkConfiguration, string endpoint = "http://localhost:4317", Serilog.Sinks.OpenTelemetry.OtlpProtocol protocol = 0, System.Collections.Generic.IDictionary<string, string>? headers = null, System.Collections.Generic.IDictionary<string, object>? resourceAttributes = null, Serilog.Sinks.OpenTelemetry.IncludedData? includedData = default) { }
         public static Serilog.LoggerConfiguration OpenTelemetry(this Serilog.Configuration.LoggerSinkConfiguration loggerSinkConfiguration, string endpoint = "http://localhost:4317", Serilog.Sinks.OpenTelemetry.OtlpProtocol protocol = 0, System.Collections.Generic.IDictionary<string, string>? headers = null, System.Collections.Generic.IDictionary<string, object>? resourceAttributes = null, Serilog.Sinks.OpenTelemetry.IncludedData? includedData = default, Serilog.Events.LogEventLevel restrictedToMinimumLevel = 0, Serilog.Core.LoggingLevelSwitch? levelSwitch = null) { }
     }