Merge pull request #126 from xsnippet/tracing

Add basic logging

Cargo.toml

@@ -23,4 +23,6 @@ rocket = "0.4.5"
 rocket_contrib = {version = "0.4.5", features = ["json"]}
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+tracing = "0.1.25"
+tracing-subscriber = "0.2.16"
 uuid = { version = "0.8.2", features = ["v4"] }

src/application.rs

@@ -3,7 +3,7 @@ use std::error::Error;
 
 use super::routes;
 use super::storage::{SqlStorage, Storage};
-use super::web::RequestIdHeader;
+use super::web::{RequestIdHeader, RequestSpan};
 
 #[derive(Debug)]
 pub struct Config {
@@ -51,5 +51,6 @@ pub fn create_app() -> Result<rocket::Rocket, Box<dyn Error>> {
         .manage(Config { syntaxes })
         .manage(storage)
         .attach(RequestIdHeader)
+        .attach(RequestSpan)
         .mount("/v1", routes))
 }

src/errors.rs

@@ -74,14 +74,14 @@ impl<'r> Responder<'r> for ApiError {
     fn respond_to(self, request: &Request) -> response::Result<'r> {
         if let ApiError::InternalError(_) = self {
             // do not give away any details for internal server errors
-            // TODO: integrate with Rocket contextual logging when 0.5 is released
-            eprintln!("Internal server error: {}", self.reason());
+            error!("Internal server error: {}", self.reason());
             Response::build()
                 .status(http::Status::InternalServerError)
                 .ok()
         } else {
             // otherwise, present the error in the requested data format
             let http_status = self.status();
+            debug!("ApiError: {:?}", self);
             Response::build_from(Output(self).respond_to(request)?)
                 .status(http_status)
                 .ok()

src/main.rs

@@ -9,18 +9,34 @@
 extern crate diesel;
 #[macro_use]
 extern crate rocket;
+#[macro_use]
+extern crate tracing;
 
 mod application;
 mod errors;
 mod routes;
 mod storage;
 mod web;
 
+use tracing_subscriber::{fmt, EnvFilter};
+
 fn main() {
+    // set up logging of application events to stderr
+    let tracing_config = rocket::config::RocketConfig::active_default()
+        .expect("failed to read Rocket config")
+        .active()
+        .get_string("tracing")
+        .unwrap_or_else(|_| String::from("info"));
+    let subscriber = fmt()
+        .with_env_filter(EnvFilter::new(tracing_config))
+        .with_writer(std::io::stderr)
+        .finish();
+    tracing::subscriber::set_global_default(subscriber).expect("setting default subscriber failed");
+
     let app = match application::create_app() {
         Ok(app) => app,
         Err(err) => {
-            eprintln!("error: {}", err);
+            error!("error: {}", err);
             std::process::exit(1);
         }
     };

src/storage/sql/mod.rs

@@ -390,7 +390,7 @@ mod tests {
 
             test_function(Box::new(SqlStorage { pool }));
         } else {
-            eprintln!("ROCKET_DATABASE_URL is not set, skipping the test");
+            error!("ROCKET_DATABASE_URL is not set, skipping the test");
         }
     }