Add ecosystem crates to readme (#312)

README.md

@@ -49,6 +49,67 @@ fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
 
 See the [examples](./examples) directory for different integration patterns.
 
+## Ecosystem
+
+### Related Crates
+
+In addition to `opentelemetry`, the [`open-telemetry/opentelemetry-rust`]
+repository contains several additional crates designed to be used with the
+`opentelemetry` ecosystem. This includes a collection of trace `SpanExporter`
+and metrics pull and push controller implementations, as well as utility and
+adapter crates to assist in propagating state and instrumenting applications.
+
+In particular, the following crates are likely to be of interest:
+
+- [`opentelemetry-jaeger`] provides a pipeline and exporter for sending trace
+  information to [`Jaeger`].
+- [`opentelemetry-otlp`] exporter for sending trace and metric data in the OTLP
+  format to the OpenTelemetry collector.
+- [`opentelemetry-prometheus`] provides a pipeline and exporter for sending
+  metrics information to [`Prometheus`].
+- [`opentelemetry-zipkin`] provides a pipeline and exporter for sending trace
+  information to [`Zipkin`].
+- [`opentelemetry-contrib`] provides additional exporters to vendors like
+  [`Datadog`].
+- [`opentelemetry-semantic-conventions`] provides standard names and semantic
+  otel conventions.
+
+Additionally, there are also several third-party crates which are not
+maintained by the `opentelemetry` project. These include:
+
+- [`tracing-opentelemetry`] provides integration for applications instrumented
+  using the [`tracing`] API and ecosystem.
+- [`actix-web-opentelemetry`] provides integration for the [`actix-web`] web
+  server and ecosystem.
+- [`opentelemetry-application-insights`] provides an unofficial [Azure
+  Application Insights] exporter.
+- [`opentelemetry-tide`] provides integration for the [`Tide`] web server and
+  ecosystem.
+
+If you're the maintainer of an `opentelemetry` ecosystem crate not listed
+above, please let us know! We'd love to add your project to the list!
+
+[`open-telemetry/opentelemetry-rust`]: /~https://github.com/open-telemetry/opentelemetry-rust
+[`opentelemetry-jaeger`]: https://crates.io/crates/opentelemetry-jaeger
+[`Jaeger`]: https://www.jaegertracing.io
+[`opentelemetry-otlp`]: https://crates.io/crates/opentelemetry-otlp
+[`opentelemetry-prometheus`]: https://crates.io/crates/opentelemetry-prometheus
+[`Prometheus`]: https://prometheus.io
+[`opentelemetry-zipkin`]: https://crates.io/crates/opentelemetry-zipkin
+[`Zipkin`]: https://zipkin.io
+[`opentelemetry-contrib`]: https://crates.io/crates/opentelemetry-contrib
+[`Datadog`]: https://www.datadoghq.com
+[`opentelemetry-semantic-conventions`]: https://crates.io/crates/opentelemetry-semantic-conventions
+
+[`tracing-opentelemetry`]: https://crates.io/crates/tracing-opentelemetry
+[`tracing`]: https://crates.io/crates/tracing
+[`actix-web-opentelemetry`]: https://crates.io/crates/actix-web-opentelemetry
+[`actix-web`]: https://crates.io/crates/actix-web
+[`opentelemetry-application-insights`]: https://crates.io/crates/opentelemetry-application-insights
+[Azure Application Insights]: https://docs.microsoft.com/en-us/azure/azure-monitor/app/app-insights-overview
+[`opentelemetry-tide`]: https://crates.io/crates/opentelemetry-tide
+[`Tide`]: https://crates.io/crates/tide
+
 ## Supported Rust Versions
 
 OpenTelemetry is built against the latest stable release. The minimum supported

src/api/mod.rs

@@ -1,6 +1,8 @@
 pub mod baggage;
 pub(crate) mod context;
 pub(crate) mod core;
+#[cfg(feature = "metrics")]
+#[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
 pub mod labels;
 #[cfg(feature = "metrics")]
 #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]

src/lib.rs

@@ -30,6 +30,66 @@
 //! See the [examples](/~https://github.com/open-telemetry/opentelemetry-rust/tree/master/examples)
 //! directory for different integration patterns.
 //!
+//! ## Related Crates
+//!
+//! In addition to `opentelemetry`, the [`open-telemetry/opentelemetry-rust`]
+//! repository contains several additional crates designed to be used with the
+//! `opentelemetry` ecosystem. This includes a collection of trace
+//! `SpanExporter` and metrics pull and push controller implementations, as well
+//! as utility and adapter crates to assist in propagating state and
+//! instrumenting applications.
+//!
+//! In particular, the following crates are likely to be of interest:
+//!
+//! - [`opentelemetry-jaeger`] provides a pipeline and exporter for sending
+//!   trace information to [`Jaeger`].
+//! - [`opentelemetry-otlp`] exporter for sending trace and metric data in the
+//!   OTLP format to the OpenTelemetry collector.
+//! - [`opentelemetry-prometheus`] provides a pipeline and exporter for sending
+//!   metrics information to [`Prometheus`].
+//! - [`opentelemetry-zipkin`] provides a pipeline and exporter for sending
+//!   trace information to [`Zipkin`].
+//! - [`opentelemetry-contrib`] provides additional exporters to vendors like
+//!   [`Datadog`].
+//! - [`opentelemetry-semantic-conventions`] provides standard names and
+//!   semantic otel conventions.
+//!
+//! Additionally, there are also several third-party crates which are not
+//! maintained by the `opentelemetry` project. These include:
+//!
+//! - [`tracing-opentelemetry`] provides integration for applications
+//!   instrumented using the [`tracing`] API and ecosystem.
+//! - [`actix-web-opentelemetry`] provides integration for the [`actix-web`] web
+//!   server and ecosystem.
+//! - [`opentelemetry-application-insights`] provides an unofficial [Azure
+//!   Application Insights] exporter.
+//! - [`opentelemetry-tide`] provides integration for the [`Tide`] web server
+//!   and ecosystem.
+//!
+//! If you're the maintainer of an `opentelemetry` ecosystem crate not listed
+//! above, please let us know! We'd love to add your project to the list!
+//!
+//! [`open-telemetry/opentelemetry-rust`]: /~https://github.com/open-telemetry/opentelemetry-rust
+//! [`opentelemetry-jaeger`]: https://crates.io/crates/opentelemetry-jaeger
+//! [`Jaeger`]: https://www.jaegertracing.io
+//! [`opentelemetry-otlp`]: https://crates.io/crates/opentelemetry-otlp
+//! [`opentelemetry-prometheus`]: https://crates.io/crates/opentelemetry-prometheus
+//! [`Prometheus`]: https://prometheus.io
+//! [`opentelemetry-zipkin`]: https://crates.io/crates/opentelemetry-zipkin
+//! [`Zipkin`]: https://zipkin.io
+//! [`opentelemetry-contrib`]: https://crates.io/crates/opentelemetry-contrib
+//! [`Datadog`]: https://www.datadoghq.com
+//! [`opentelemetry-semantic-conventions`]: https://crates.io/crates/opentelemetry-semantic-conventions
+//!
+//! [`tracing-opentelemetry`]: https://crates.io/crates/tracing-opentelemetry
+//! [`tracing`]: https://crates.io/crates/tracing
+//! [`actix-web-opentelemetry`]: https://crates.io/crates/actix-web-opentelemetry
+//! [`actix-web`]: https://crates.io/crates/actix-web
+//! [`opentelemetry-application-insights`]: https://crates.io/crates/opentelemetry-application-insights
+//! [Azure Application Insights]: https://docs.microsoft.com/en-us/azure/azure-monitor/app/app-insights-overview
+//! [`opentelemetry-tide`]: https://crates.io/crates/opentelemetry-tide
+//! [`Tide`]: https://crates.io/crates/tide
+//!
 //! ## Supported Rust Versions
 //!
 //! OpenTelemetry is built against the latest stable release. The minimum
@@ -70,6 +130,9 @@ pub mod sdk;
 #[cfg(test)]
 pub mod testing;
 
+#[cfg(feature = "metrics")]
+#[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
+pub use api::labels;
 #[cfg(feature = "metrics")]
 #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
 pub use api::metrics;
@@ -80,5 +143,5 @@ pub use api::{
     baggage,
     context::{Context, ContextGuard},
     core::{Key, KeyValue, Unit, Value},
-    labels, propagation,
+    propagation,
 };

src/sdk/resource.rs

@@ -13,7 +13,9 @@
 //! produced by any `Tracer` from the provider are associated with this `Resource`.
 //!
 //! [`TracerProvider`]: ../../api/trace/provider/trait.TracerProvider.html
-use crate::{labels, Key, KeyValue, Value};
+#[cfg(feature = "metrics")]
+use crate::labels;
+use crate::{Key, KeyValue, Value};
 #[cfg(feature = "serialize")]
 use serde::{Deserialize, Serialize};
 use std::collections::{btree_map, btree_map::Entry, BTreeMap};
@@ -105,6 +107,8 @@ impl Resource {
     }
 
     /// Encoded labels
+    #[cfg(feature = "metrics")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
     pub fn encoded(&self, encoder: &dyn labels::Encoder) -> String {
         encoder.encode(&mut self.into_iter())
     }