Restructure for testability and implement first tests

src/telemetry.rs

@@ -0,0 +1,21 @@
+use tracing::{subscriber::set_global_default, Subscriber};
+use tracing_bunyan_formatter::{BunyanFormattingLayer, JsonStorageLayer};
+use tracing_log::LogTracer;
+use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
+
+pub fn get_subscriber(name: &str, env_filter: &str) -> impl Subscriber + Send + Sync {
+    let env_filter =
+        EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(env_filter));
+
+    let formatting_layer = BunyanFormattingLayer::new(name.to_string(), std::io::stdout);
+
+    Registry::default()
+        .with(env_filter)
+        .with(JsonStorageLayer)
+        .with(formatting_layer)
+}
+
+pub fn init_subscriber(subscriber: impl Subscriber + Send + Sync) {
+    LogTracer::init().expect("Failed to set logger");
+    set_global_default(subscriber).expect("Failed to set tracing subscriber");
+}