From e1fbe36297874908b75f3061e715ba591d08aacd Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Mon, 27 Mar 2023 17:06:22 -0400
Subject: [PATCH] Exporting traces to jaeger.

---
 Cargo.toml  |  3 +++
 src/main.rs | 26 ++++++++++++++++++--------
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index bc11dfc0..627ec01f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,10 @@ path = "src/main.rs"
 
 [dependencies]
 nom = "7.1.1"
+opentelemetry = "0.17.0"
+opentelemetry-jaeger = "0.16.0"
 tracing = "0.1.37"
+tracing-opentelemetry = "0.17.2"
 tracing-subscriber = {version="0.3.16", features=["env-filter"]}
 
 [features]
diff --git a/src/main.rs b/src/main.rs
index 2d4a3dcb..cc494715 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,10 @@
 #![feature(round_char_boundary)]
 use crate::parser::document;
-use tracing_subscriber::fmt::format::FmtSpan;
 use tracing_subscriber::EnvFilter;
 mod parser;
+use tracing_subscriber::fmt;
+use tracing_subscriber::layer::SubscriberExt;
+use tracing_subscriber::util::SubscriberInitExt;
 
 const TEST_DOC: &'static str = include_str!("../toy_language.txt");
 
@@ -16,17 +18,25 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
 fn init_telemetry() -> Result<(), Box<dyn std::error::Error>> {
     let env_filter = EnvFilter::try_from_default_env().unwrap_or(EnvFilter::new("WARN"));
-    let format = tracing_subscriber::fmt::format()
+
+    let stdout = fmt::Layer::new()
         .pretty()
         .with_file(true)
         .with_line_number(true)
         .with_thread_ids(false)
         .with_target(false);
-    let subscriber = tracing_subscriber::fmt()
-        .event_format(format)
-        .with_span_events(FmtSpan::ENTER | FmtSpan::EXIT)
-        .with_env_filter(env_filter)
-        .finish();
-    tracing::subscriber::set_global_default(subscriber)?;
+
+    opentelemetry::global::set_text_map_propagator(opentelemetry_jaeger::Propagator::new());
+    let tracer = opentelemetry_jaeger::new_pipeline()
+        .with_service_name("toy_language")
+        .install_simple()?;
+
+    let opentelemetry = tracing_opentelemetry::layer().with_tracer(tracer);
+
+    tracing_subscriber::registry()
+        .with(env_filter)
+        .with(opentelemetry)
+        .with(stdout)
+        .try_init()?;
     Ok(())
 }