Update opentelemetry to 0.18 and make it optional via a feature

CHANGELOG.md

@@ -8,6 +8,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Added
 - `default-tls`, `rustls-native`, and `rustls-webpki` features to allow usage of rustls for the https client
 ### Changed
+- `opentelemetry` feature must be specified to enable opentelemetry support.
+- `opentelemetry` updated to version `0.18`.
+- `base64` updated to version `0.20`.
 ### Deprecated
 ### Removed
 ### Fixed

Cargo.toml

@@ -15,17 +15,18 @@ default-tls  = ["hyper-tls"]
 metrics = ["prometheus", "lazy_static"]
 rustls-native = ["hyper-rustls/rustls-native-certs"]
 rustls-webpki = ["hyper-rustls/webpki-roots"]
+opentelemetry = ["dep:opentelemetry"]
 
 # keep this list sorted!
 [dependencies]
-base64 = "0.13.0"
+base64 = "0.20.0"
 futures = "0.3.8"
 http = "0.2.1"
 hyper = { version = "0.14.2", features = ["full"] }
 hyper-rustls = { version = "0.22.1", optional = true }
-hyper-tls = { version = "0.5.0", optional = true, no-default-features = true }
+hyper-tls = { version = "0.5.0", optional = true, default-features = true }
 lazy_static = { version = "1.4.0", optional = true }
-opentelemetry = { version = "0.15", features = ["tokio", "rt-tokio"] }
+opentelemetry = { version = "0.18", features = ["rt-tokio"], optional = true }
 prometheus = { version = "0.13", optional = true }
 quick-error = "2.0"
 serde = { version = "1.0", features = ["derive"] }

src/hyper_wrapper.rs

@@ -25,7 +25,7 @@ SOFTWARE.
 use hyper::Version;
 use opentelemetry::{
     global::{BoxedSpan, BoxedTracer},
-    trace::{Span, StatusCode, Tracer},
+    trace::{Span, Status, Tracer},
     KeyValue,
 };
 
@@ -84,6 +84,6 @@ pub fn annotate_span_for_response<T>(span: &mut BoxedSpan, response: &hyper::Res
     }
 
     if status != hyper::StatusCode::OK {
-        span.set_status(StatusCode::Error, status.as_str().to_owned());
+        span.set_status(Status::error(status.as_str().to_owned()));
     }
 }

src/lib.rs

@@ -39,17 +39,23 @@ use hyper_tls::HttpsConnector;
 
 #[cfg(feature = "metrics")]
 use lazy_static::lazy_static;
-use opentelemetry::global;
-use opentelemetry::global::BoxedTracer;
-use opentelemetry::trace::Span;
-use opentelemetry::trace::StatusCode;
 use quick_error::quick_error;
 use serde::{Deserialize, Serialize};
 use slog_scope::{error, info};
 use tokio::time::timeout;
 
+#[cfg(feature="opentelemetry")]
+use opentelemetry::global;
+#[cfg(feature="opentelemetry")]
+use opentelemetry::global::BoxedTracer;
+#[cfg(feature="opentelemetry")]
+use opentelemetry::trace::Span;
+#[cfg(feature="opentelemetry")]
+use opentelemetry::trace::Status;
+
 pub use types::*;
 
+#[cfg(feature="opentelemetry")]
 mod hyper_wrapper;
 /// The strongly typed data structures representing canonical consul objects.
 pub mod types;
@@ -214,6 +220,7 @@ impl Drop for Lock<'_> {
 pub struct Consul {
     https_client: hyper::Client<HttpsConnector<HttpConnector>, Body>,
     config: Config,
+    #[cfg(feature="opentelemetry")]
     tracer: BoxedTracer,
 }
 
@@ -237,6 +244,7 @@ impl Consul {
         Consul {
             https_client,
             config,
+            #[cfg(feature="opentelemetry")]
             tracer: global::tracer("consul"),
         }
     }
@@ -671,6 +679,7 @@ impl Consul {
             )
             .body(body);
         let req = req.map_err(ConsulError::RequestError)?;
+        #[cfg(feature="opentelemetry")]
         let mut span = crate::hyper_wrapper::span_for_request(&self.tracer, &req);
 
         let method = req.method().clone();
@@ -698,6 +707,7 @@ impl Consul {
 
         let response = response?;
 
+        #[cfg(feature="opentelemetry")]
         crate::hyper_wrapper::annotate_span_for_response(&mut span, &response);
 
         let status = response.status();
@@ -725,7 +735,8 @@ impl Consul {
             Err(e) => {
                 record_failure_metric_if_enabled(&method, request_name);
 
-                span.set_status(StatusCode::Error, e.to_string());
+                #[cfg(feature="opentelemetry")]
+                span.set_status(Status::error(e.to_string()));
                 Err(ConsulError::InvalidResponse(e))
             }
         }