Configure the EDOT .NET SDK

Configure the Elastic Distribution of OpenTelemetry .NET (EDOT .NET) to send data to Elastic.

Configure the OpenTelemetry SDK using the mechanisms listed in the OpenTelemetry documentation, including:

• Setting environment variables.
• Using the IConfiguration integration.
• Manually configuring EDOT .NET.
• Central configuration.

Configuration options set manually in code take precedence over environment variables, and environment variables take precedence over configuration options set using the IConfiguration system. Central configuration is evaluated last and takes precedence over all other configuration sources.

You can configure EDOT .NET using environment variables. This is a cross-platform way to configure EDOT .NET and is especially useful in containerized environments.

Environment variables are read at startup and can be used to configure EDOT .NET. For details of the various EDOT-specific options available and their corresponding environment variable names, see Configuration options.

All OpenTelemetry environment variables from the contrib SDK may also be used to configure the SDK behavior for features such as resources, samples and exporters.

In applications that use the ".NET generic host", such as ASP.NET Core and worker services, EDOT .NET can be configured using the IConfiguration integration.

When using an IHostApplicationBuilder in modern ASP.NET Core applications, the AddElasticOpenTelemetry extension method turns on EDOT .NET and configuration from IHostApplicationBuilder.Configuration is passed in automatically. For example:

var builder = WebApplication.CreateBuilder(args);
// Configuration is automatically bound and can be provided
// via the `appsettings.json` file.
builder.AddElasticOpenTelemetry();
		

By default, at this stage the configuration is populated from the default configuration sources, including the appsettings.json file(s) and command-line arguments. You can use these sources to define the configuration for the Elastic Distribution of OpenTelemetry .NET.

For example, you can define the configuration for the Elastic Distribution of OpenTelemetry .NET in the appsettings.json file:

{
  "Elastic": {
    "OpenTelemetry": {
      "LogDirectory": "C:\\Logs"
    }
  }
}
		

Configuration parsed from the Elastic:OpenTelemetry section of the IConfiguration instance is bound to the ElasticOpenTelemetryOptions instance used to configure EDOT .NET.

In situations where the application might not depend on the hosting APIs, but uses the dependency injection APIs instead, an IConfiguration instance can be passed in manually. This is usually the case with console applications. For example:

var configuration = new ConfigurationBuilder()
    .AddInMemoryCollection(new Dictionary<string, string?>()
    {
        ["Elastic:OpenTelemetry:LogDirectory"] = "C:\\Logs"
    })
    .Build();

var services = new ServiceCollection();
services.AddElasticOpenTelemetry(configuration);
		

To learn more about the Microsoft configuration system, see Configuration in ASP.NET Core.

In all other scenarios, you can configure EDOT .NET manually in code.

Create an instance of ElasticOpenTelemetryOptions and pass it to an overload of the WithElasticDefaults extension methods available on the IHostApplicationBuilder, the IServiceCollection and the specific signal providers such as TracerProviderBuilder.

For example, in traditional console applications, you can configure the Elastic Distribution of OpenTelemetry .NET like this:

using OpenTelemetry;
using Elastic.OpenTelemetry;

// Create an instance of `ElasticOpenTelemetryOptions`.
var options = new ElasticOpenTelemetryOptions
{
  // This example sets the file log directory to `C:\Logs`
  // which enables diagnostic file logging.
  FileLogDirectory = "C:\\Logs"
};

// Pass the `ElasticOpenTelemetryOptions` instance to the
// `WithElasticDefaults` extension method for the `IOpenTelemetryBuilder`
//  to configure EDOT .NET.
using var sdk = OpenTelemetrySdk.Create(builder => builder
  .WithElasticDefaults(options));
		

Because the Elastic Distribution of OpenTelemetry .NET (EDOT .NET) is an extension of the OpenTelemetry .NET SDK, it supports both:

• General OpenTelemetry SDK configuration options
• Elastic-specific configuration options that are only available when using EDOT .NET

EDOT .NET supports all configuration options listed in the OpenTelemetry General SDK Configuration documentation.

EDOT .NET supports the following Elastic-specific options.

• Type: String
• Default: string.Empty

A string specifying the output directory where the Elastic Distribution of OpenTelemetry .NET writes diagnostic log files. When not provided, no file logging occurs. Each new .NET process creates a new log file in the specified directory.

• Type: String
• Default: Information

Sets the logging level for EDOT .NET. Valid options are Critical, Error, Warning, Information, Debug, Trace, and None. None disables the logging.

• Type: String
• Default: Information

A comma-separated list of targets for log output. When global logging is not configured (a log directory or target is not specified) this defaults to none. When the instrumented application is running within a container, this defaults to direct logs to stdout. Otherwise defaults to file.

Valid options are file, stdout and none. None disables the logging.

• Type: Bool
• Default: false

Allows EDOT .NET to be used with its defaults, but without enabling the export of telemetry data to an OTLP endpoint. This can be useful when you want to test applications without sending telemetry data.

• Type: Bool
• Default: false

Allows EDOT .NET to be used without the instrumentation assembly scanning feature turned on. This prevents the automatic registration of instrumentation from referenced OpenTelemetry contrib instrumentation packages.

• Type: String
• Default: string.Empty

The OpAMP server endpoint used for central configuration. When set, EDOT .NET connects to the specified endpoint to receive remote configuration updates. Setting this option also requires a service name. EDOT .NET resolves the service name from OTEL_SERVICE_NAME first; if that is not set, it falls back to the service.name key within OTEL_RESOURCE_ATTRIBUTES. If neither is configured, central configuration is silently deactivated.

• Type: String
• Default: string.Empty

A comma-separated list of HTTP headers in Key=Value format to include in requests to the OpAMP server. Use this to pass authentication credentials required by the OpAMP server.

To secure the connection to the OTLP endpoint using TLS, you can configure the following environment variables as documented in the OpenTelemetry OTLP Exporter specification:

Signal-specific variants are also supported: OTEL_EXPORTER_OTLP_{TRACES,METRICS,LOGS}_CERTIFICATE, OTEL_EXPORTER_OTLP_{TRACES,METRICS,LOGS}_CLIENT_CERTIFICATE, and OTEL_EXPORTER_OTLP_{TRACES,METRICS,LOGS}_CLIENT_KEY.

Central configuration allows you to manage EDOT .NET settings remotely without redeploying. When turned on, EDOT .NET connects to an OpAMP-compatible server (the EDOT Collector configured with the Elastic APM Config Extension) and receives configuration at startup from Elastic Observability.

Central configuration takes precedence over all other configuration sources (environment variables and IConfiguration). When a remote value is removed, the locally configured value is restored on the next agent startup.

To turn on the central configuration, set the OpAMP server endpoint using one of the following methods:

Environment variable:

export ELASTIC_OTEL_OPAMP_ENDPOINT=http://your-collector:4320/v1/opamp
		

$env:ELASTIC_OTEL_OPAMP_ENDPOINT = "http://your-collector:4320/v1/opamp"
		

IConfiguration (for example, appsettings.json):

{
  "Elastic": {
    "OpenTelemetry": {
      "OpAmpEndpoint": "http://your-collector:4320/v1/opamp"
    }
  }
}
		

Code:

var options = new ElasticOpenTelemetryOptions
{
    OpAmpClientOptions = new OpAmpClientOptions
    {
        Endpoint = "http://your-collector:4320/v1/opamp"
    }
};
		

Central configuration also requires a service name so that EDOT .NET can identify itself to the OpAMP server. EDOT .NET resolves the service name in the following order:

1. OTEL_SERVICE_NAME environment variable (or the same key in IConfiguration)
2. The service.name key within OTEL_RESOURCE_ATTRIBUTES (used as a fallback if OTEL_SERVICE_NAME is not set)

For example, using OTEL_SERVICE_NAME:

export OTEL_SERVICE_NAME=my-service
		

$env:OTEL_SERVICE_NAME = "my-service"
		

Or embedding it in the resource attributes:

export OTEL_RESOURCE_ATTRIBUTES="service.name=my-service,service.version=1.0.0"
		

$env:OTEL_RESOURCE_ATTRIBUTES = "service.name=my-service,service.version=1.0.0"
		

If neither is configured, central configuration is silently deactivated.

To pass authentication credentials to the OpAMP server, set the headers option alongside the endpoint:

export ELASTIC_OTEL_OPAMP_HEADERS="Authorization=Bearer <token>"
		

$env:ELASTIC_OTEL_OPAMP_HEADERS = "Authorization=Bearer <token>"
		

HTTPS endpoints are supported for the OpAMP connection. Custom certificate verification and mutual TLS (mTLS) for the OpAMP endpoint are not yet available.

The following settings can be changed through central configuration:

To prevent logs from being exported, set OTEL_LOGS_EXPORTER to none. However, application logs might still be gathered and exported by the Collector through the filelog receiver.

To prevent application logs from being collected and exported by the Collector, refer to Exclude paths from logs collection.