OpenTelemetry Tracing

WireMock.Net supports distributed tracing via System.Diagnostics.Activity and can export traces using OpenTelemetry.

Activity Tracing

WireMock.Net creates System.Diagnostics.Activity objects for request tracing when ActivityTracingOptions is configured. This uses the built-in .NET distributed tracing infrastructure.

Basic Configuration

var settings = new WireMockServerSettings
{
    ActivityTracingOptions = new ActivityTracingOptions
    {
        ExcludeAdminRequests = true,
        RecordRequestBody = false,
        RecordResponseBody = false,
        RecordMatchDetails = true
    }
};

var server = WireMockServer.Start(settings);

ActivityTracingOptions Properties

Property	Description	Default
ExcludeAdminRequests	Exclude /__admin/* from tracing	true
RecordRequestBody	Include request body in trace attributes	false
RecordResponseBody	Include response body in trace attributes	false
RecordMatchDetails	Include mapping match details in trace attributes	true

OpenTelemetry Export

To export traces to an OpenTelemetry collector, install the WireMock.Net.OpenTelemetry package:

dotnet add package WireMock.Net.OpenTelemetry

Using AdditionalServiceRegistration

using WireMock.OpenTelemetry;
using WireMock.Server;
using WireMock.Settings;

var settings = new WireMockServerSettings
{
    ActivityTracingOptions = new ActivityTracingOptions
    {
        ExcludeAdminRequests = true,
        RecordMatchDetails = true
    },
    AdditionalServiceRegistration = services =>
    {
        services.AddWireMockOpenTelemetry(new OpenTelemetryOptions
        {
            ExcludeAdminRequests = true,
            OtlpExporterEndpoint = "http://localhost:4317"
        });
    }
};

var server = WireMockServer.Start(settings);

Custom TracerProvider Configuration

using OpenTelemetry;
using OpenTelemetry.Trace;
using WireMock.OpenTelemetry;

using var tracerProvider = Sdk.CreateTracerProviderBuilder()
    .AddWireMockInstrumentation(new OpenTelemetryOptions())
    .AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("http://localhost:4317");
    })
    .Build();

OpenTelemetryOptions Properties

Property	Description	Default
ExcludeAdminRequests	Exclude /__admin/* from ASP.NET Core instrumentation	true
OtlpExporterEndpoint	OTLP collector endpoint URL	Uses OTEL_EXPORTER_OTLP_ENDPOINT env var

Trace Attributes

WireMock traces include standard HTTP attributes and WireMock-specific attributes:

HTTP attributes:

• http.request.method
• url.full
• url.path
• server.address
• http.response.status_code
• client.address

WireMock attributes:

• wiremock.mapping.matched - Whether a mapping was found
• wiremock.mapping.guid - GUID of the matched mapping
• wiremock.mapping.title - Title of the matched mapping
• wiremock.match.score - Match score
• wiremock.request.guid - GUID of the request

CLI Arguments

When using WireMock.Net.StandAlone or Docker, configure tracing via command-line arguments:

Activity Tracing:

--ActivityTracingEnabled true
--ActivityTracingExcludeAdminRequests true
--ActivityTracingRecordRequestBody false
--ActivityTracingRecordResponseBody false
--ActivityTracingRecordMatchDetails true

OpenTelemetry Export:

--OpenTelemetryEnabled true
--OpenTelemetryOtlpExporterEndpoint http://localhost:4317
--OpenTelemetryExcludeAdminRequests true