Cleanup external-otlp examples

* Fix comment header to use simpler language
* Fix comment header to refer to correct binary
* Coalesce use statements
* Update env_logger to 0.9.0
* ensure that both examples are formatted the same

examples/external-otlp-grpcio-async-std/Cargo.toml

@@ -6,7 +6,7 @@ publish = false
 
 [dependencies]
 async-std = { version = "= 1.10.0", features = ["attributes"] }
-env_logger = "0.8.2"
+env_logger = "0.9.0"
 opentelemetry = { path = "../../opentelemetry", features = ["rt-async-std"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = [
     "grpc-sys",

examples/external-otlp-grpcio-async-std/src/main.rs

@@ -1,16 +1,17 @@
-//! This should show how to connect to a third party collector like
-//! honeycomb or lightstep using tonic with tls and using tokio as reactor.
-//! To run this you have to specify a few environment variables like in the example:
+//! This shows how to connect to a third party collector like
+//! honeycomb or lightstep using grpcio with tls and using async-std as reactor.
+//! To run this specify a few environment variables like in the example:
 //! ```shell
 //! OTLP_GRPCIO_ENDPOINT=https://api.honeycomb.io:443 \
 //! OTLP_GRPCIO_X_HONEYCOMB_TEAM=token \
 //! OTLP_GRPCIO_X_HONEYCOMB_DATASET=dataset \
-//! cargo run --bin external-otlp-tonic-tokio
+//! cargo run --bin external-otlp-grpcio-async-std
 //! ```
 use async_std::task::sleep;
-use opentelemetry::trace::TraceError;
-use opentelemetry::{global, sdk::trace as sdktrace};
 use opentelemetry::{
+    global::{shutdown_tracer_provider, tracer},
+    sdk::trace as sdktrace,
+    trace::TraceError,
     trace::{TraceContextExt, Tracer},
     Key,
 };
@@ -19,12 +20,9 @@ use url::Url;
 
 use std::{
     collections::HashMap,
-    env::{set_var, vars},
-    time::Duration,
-};
-use std::{
-    env::{remove_var, var},
+    env::{remove_var, set_var, var, vars},
     error::Error,
+    time::Duration,
 };
 
 // Use the variables to try and export the example to any external collector that accepts otlp
@@ -40,8 +38,8 @@ fn init_tracer() -> Result<sdktrace::Tracer, TraceError> {
         )
     });
     let endpoint = Url::parse(&endpoint).expect("endpoint is not a valid url");
-
     remove_var(ENDPOINT);
+
     let headers: HashMap<_, _> = vars()
         .filter(|(name, _)| name.starts_with(HEADER_PREFIX))
         .map(|(name, value)| {
@@ -71,6 +69,7 @@ fn init_tracer() -> Result<sdktrace::Tracer, TraceError> {
         )
         .install_batch(opentelemetry::runtime::AsyncStd)
 }
+
 const LEMONS_KEY: Key = Key::from_static_str("ex.com/lemons");
 const ANOTHER_KEY: Key = Key::from_static_str("ex.com/another");
 
@@ -82,7 +81,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     env_logger::init();
     let _ = init_tracer()?;
 
-    let tracer = global::tracer("ex.com/basic");
+    let tracer = tracer("ex.com/basic");
 
     tracer.in_span("operation", |cx| {
         let span = cx.span();
@@ -103,6 +102,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     // wait for 1 minutes so that we could see metrics being pushed via OTLP every 10 seconds.
     sleep(Duration::from_secs(60)).await;
 
-    global::shutdown_tracer_provider();
+    shutdown_tracer_provider();
+
     Ok(())
 }

examples/external-otlp-tonic-tokio/Cargo.toml

@@ -5,9 +5,10 @@ edition = "2021"
 publish = false
 
 [dependencies]
-opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
-opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = ["tonic", "tls", "tls-roots"] }
+env_logger = "0.9.0"
+opentelemetry = {path = "../../opentelemetry", features = ["rt-tokio", "metrics"]}
+opentelemetry-otlp = {path = "../../opentelemetry-otlp", features = ["tonic", "tls", "tls-roots"]}
 serde_json = "1.0"
-tokio = { version = "1.0", features = ["full"] }
-tonic = { version = "0.8.0", features = ["tls"] }
+tokio = {version = "1.0", features = ["full"]}
+tonic = {version = "0.8.0", features = ["tls"]}
 url = "2.2.0"

examples/external-otlp-tonic-tokio/src/main.rs

@@ -1,16 +1,16 @@
-//! This should show how to connect to a third party collector like
+//! This shows how to connect to a third party collector like
 //! honeycomb or lightstep using tonic with tls and using tokio as reactor.
-//! To run this you have to specify a few environment variables like in the example:
+//! To run this specify a few environment variables like in the example:
 //! ```shell
 //! OTLP_TONIC_ENDPOINT=https://api.honeycomb.io:443 \
 //! OTLP_TONIC_X_HONEYCOMB_TEAM=token \
-//! OTLP_TONIC_X_HONEYCOMB_DATASET=dataset \'
+//! OTLP_TONIC_X_HONEYCOMB_DATASET=dataset \
 //! cargo run --bin external-otlp-tonic-tokio
 //! ```
-use opentelemetry::trace::TraceError;
-use opentelemetry::{global, sdk::trace as sdktrace};
 use opentelemetry::{
-    trace::{TraceContextExt, Tracer},
+    global::{shutdown_tracer_provider, tracer},
+    sdk::trace as sdktrace,
+    trace::{TraceContextExt, TraceError, Tracer},
     Key,
 };
 use tonic::{
@@ -19,12 +19,12 @@ use tonic::{
 };
 use url::Url;
 
-use opentelemetry::global::shutdown_tracer_provider;
 use opentelemetry_otlp::WithExportConfig;
-use std::{env::vars, str::FromStr, time::Duration};
 use std::{
-    env::{remove_var, var},
+    env::{remove_var, set_var, var, vars},
     error::Error,
+    str::FromStr,
+    time::Duration,
 };
 
 // Use the variables to try and export the example to any external collector that accepts otlp
@@ -41,6 +41,7 @@ fn init_tracer() -> Result<sdktrace::Tracer, TraceError> {
     });
     let endpoint = Url::parse(&endpoint).expect("endpoint is not a valid url");
     remove_var(ENDPOINT);
+
     let mut metadata = MetadataMap::new();
     for (key, value) in vars()
         .filter(|(name, _)| name.starts_with(HEADER_PREFIX))
@@ -79,9 +80,13 @@ const ANOTHER_KEY: Key = Key::from_static_str("ex.com/another");
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
+    if let Err(std::env::VarError::NotPresent) = var("RUST_LOG") {
+        set_var("RUST_LOG", "debug")
+    };
+    env_logger::init();
     let _ = init_tracer()?;
 
-    let tracer = global::tracer("ex.com/basic");
+    let tracer = tracer("ex.com/basic");
 
     tracer.in_span("operation", |cx| {
         let span = cx.span();