OpenTelemetry support for Google Cloud Trace

Quick start

Cargo.toml:

[dependencies]
opentelemetry-gcloud-trace = "0.20"

Compatibility matrix

Example:

let gcp_trace_exporter = GcpCloudTraceExporterBuilder::for_default_project_id().await?; // or GcpCloudTraceExporterBuilder::new(config_env_var("PROJECT_ID")?)

let tracer_provider = gcp_trace_exporter.create_provider().await?;
let tracer: opentelemetry_sdk::trace::Tracer = gcp_trace_exporter.install(&tracer_provider).await?;

opentelemetry::global::set_tracer_provider(tracer_provider.clone());

tracer.in_span("doing_work_parent", |cx| {
  // ...
});

tracer_provider.shutdown()?;

All examples are available at examples directory.

To run an example use with environment variables:

# PROJECT_ID=<your-google-project-id> cargo run --example enable-exporter

[dependencies]
opentelemetry = { version = "*", features = [] }
opentelemetry_sdk = { version = "*", features = ["rt-tokio"] }
opentelemetry-gcloud-trace = "*"

Crypto provider error

Depends on your other dependencies you may see the error like:

no process-level CryptoProvider available -- call CryptoProvider::install_default() before this point 

This is because the TLS providers are not installed by default and you can choose different. The easiest way to fix is just to include one of the provider, for example:

[dependencies]
rustls = "0.23"

If you have multiple you may need to call CryptoProvider::install_default() before using the Firestore client.

rustls::crypto::ring::default_provider().install_default().expect("Failed to install rustls crypto provider");

Configuration

You can specify trace configuration using with_tracer_provider_builder:

   let exporter = GcpCloudTraceExporterBuilder::new(google_project_id);
   let provider = exporter.create_provider_from_builder ( TracerProvider::builder()
         .with_sampler(Sampler::AlwaysOn)
         .with_id_generator(RandomIdGenerator::default())
   ));

Limitations

• This exporter doesn't support any other runtimes except Tokio.

Integration with logs

This crate intentionally doesn't export logs using API to avoid duplicate logs on GKE/GCE environments. You can use this crate in combination with tracing-stackdriver crate to produce JSON formatted logs and logs and traces will be correlated by trace_id and span_id fields automatically.

This is an example of this kind of configuration:

fn init_console_log(
    tracer: opentelemetry_sdk::trace::Tracer,
) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let telemetry = tracing_opentelemetry::layer().with_tracer(tracer);

    let subscriber = tracing_subscriber::registry::Registry::default()
        .with(tracing_subscriber::fmt::layer())
        .with(tracing_subscriber::EnvFilter::from_str(
            "gcloud_sdk=debug",
        )?)
        .with(telemetry);

    tracing::subscriber::set_global_default(subscriber)?;

    Ok(())
}

fn init_stackdriver_log(
    gcp_project_id: &str,
    tracer: opentelemetry_sdk::trace::Tracer,
) -> Result<(), BoxedError> {
    let telemetry_layer = tracing_opentelemetry::layer().with_tracer(tracer);

    let stackdriver_layer = tracing_stackdriver::layer().with_cloud_trace(
        tracing_stackdriver::CloudTraceConfiguration {
            project_id: gcp_project_id.to_string(),
        },
    );

    let subscriber = tracing_subscriber::Registry::default()
        .with(telemetry_layer)
        .with(stackdriver_layer)
        .with(tracing_subscriber::EnvFilter::from_str(
            "gcloud_sdk=debug",
        )?);
    tracing::subscriber::set_global_default(subscriber)
        .expect("Could not set up global logger");

    Ok(())
}

async fn init_tracing(app_mode: &GlobalAppMode,
                      tracer: GcpCloudTraceExporter,
                      gcp_project_id: &str) -> Result<(), BoxedError> {
    match app_mode {
        GlobalAppMode::Production => init_stackdriver_log(gcp_project_id, tracer),
        GlobalAppMode::Development => init_console_log(tracer),
    }
}

#[tokio::main]
async fn main() -> Result<(), BoxedError> {
    let gcp_project_id = "my-gcp-project-id";
    let exporter = GcpCloudTraceExporterBuilder::new(gcp_project_id.into());
    let tracer_provider = gcp_trace_exporter.create_provider().await?;
    let tracer: opentelemetry_sdk::trace::Tracer = gcp_trace_exporter.install(&tracer_provider).await?;
    let app_mode = GlobalAppMode::Development;

    opentelemetry::global::set_tracer_provider(tracer_provider.clone());
    
    init_tracing(&app_mode, tracer, gcp_project_id).await?;
    
    // ...

    tracer_provider.shutdown()?;
}

TLS related features

Cargo provides support for different TLS features for dependencies:

• tls-roots: default feature to support native TLS roots
• tls-webpki-roots: feature to switch to webpki crate roots

Licence

Apache Software License (ASL)

Author

Abdulla Abdurakhmanov