5 files changed, 43 insertions, 9 deletions

diff --git a/src/db.rs b/src/db.rs
index 7e3610b..21c7db4 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -4,8 +4,10 @@ use std::env;
 const DATABASE_URL_FALLBACK: &str = "postgres://health:health@127.0.0.1:5432/health";
 
 pub async fn connect() -> Result<PgPool, sqlx::Error> {
-    let database_url =
-        env::var("DATABASE_URL").unwrap_or_else(|_| DATABASE_URL_FALLBACK.to_string());
+    let database_url = env::var("DATABASE_URL").unwrap_or_else(|_| {
+        tracing::warn!("DATABASE_URL not set, falling back to the default local database");
+        DATABASE_URL_FALLBACK.to_string()
+    });
     PgPoolOptions::new()
         .max_connections(5)
         .connect(&database_url)
diff --git a/src/error.rs b/src/error.rs
index d16106a..6bc4fc5 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -76,6 +76,9 @@ impl IntoResponse for AppError {
             AppError::NotFound => (StatusCode::NOT_FOUND, "not found".to_owned()),
             AppError::Rejection(status, message) => (status, message),
         };
+        if status.is_client_error() {
+            tracing::debug!(%status, error = %message, "request failed");
+        }
         (status, Json(json!({ "error": message }))).into_response()
     }
 }
diff --git a/src/handlers.rs b/src/handlers.rs
index 7067f3a..9ae87c3 100644
--- a/src/handlers.rs
+++ b/src/handlers.rs
@@ -29,6 +29,7 @@ pub async fn export_measurements(
     AppQuery(query): AppQuery<ListQuery>,
 ) -> Result<([(HeaderName, &'static str); 2], Vec<u8>), AppError> {
     let rows = fetch_measurements(&pool, &query).await?;
+    tracing::info!(count = rows.len(), "exporting measurements");
     let mut writer = csv::WriterBuilder::new()
         .has_headers(false)
         .from_writer(Vec::new());
@@ -65,6 +66,14 @@ async fn fetch_measurements(
     {
         return Err(AppError::BadRequest("from must not be after to"));
     }
+    tracing::debug!(
+        from = ?query.from,
+        to = ?query.to,
+        metric_type = ?query.metric_type,
+        limit = ?limit,
+        order = ?query.order,
+        "fetching measurements"
+    );
     // SQL can't bind ASC/DESC as a parameter. The CASE yields measured_at only when
     // `order` is desc (sorted DESC) and NULL otherwise, so that key ties for every
     // row and the ASC key decides the order. If this gets slow, use an if/else with a
@@ -88,6 +97,7 @@ async fn fetch_measurements(
     )
     .fetch_all(pool)
     .await?;
+    tracing::debug!(count = rows.len(), "fetched measurements");
     Ok(rows)
 }
 
@@ -110,6 +120,11 @@ pub async fn create_measurement(
     )
     .fetch_one(&pool)
     .await?;
+    tracing::info!(
+        id = %measurement.id,
+        metric_type = ?measurement.metric_type,
+        "created measurement"
+    );
     let location = format!("/measurements/{}", measurement.id);
     Ok((
         StatusCode::CREATED,
@@ -122,6 +137,7 @@ pub async fn get_measurement(
     State(pool): State<PgPool>,
     AppPath(id): AppPath<Uuid>,
 ) -> Result<Json<MeasurementView>, AppError> {
+    tracing::debug!(%id, "fetching measurement");
     let measurement = sqlx::query_as!(
         MeasurementView,
         "
@@ -160,6 +176,7 @@ pub async fn update_measurement(
     if result.rows_affected() == 0 {
         return Err(AppError::NotFound);
     }
+    tracing::info!(%id, "updated measurement");
     Ok(StatusCode::NO_CONTENT)
 }
 
@@ -167,9 +184,14 @@ pub async fn delete_measurement(
     State(pool): State<PgPool>,
     AppPath(id): AppPath<Uuid>,
 ) -> Result<StatusCode, AppError> {
-    sqlx::query!("DELETE FROM measurement WHERE id = $1", id)
+    let result = sqlx::query!("DELETE FROM measurement WHERE id = $1", id)
         .execute(&pool)
         .await?;
+    if result.rows_affected() == 0 {
+        tracing::debug!(%id, "measurement to delete did not exist");
+    } else {
+        tracing::info!(%id, "deleted measurement");
+    }
     Ok(StatusCode::NO_CONTENT)
 }
 
diff --git a/src/main.rs b/src/main.rs
index 4f34c0c..91d56b0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,6 +11,7 @@ use std::env;
 use axum::{Router, routing::get};
 use dotenvy::dotenv;
 use sqlx::PgPool;
+use tracing_subscriber::EnvFilter;
 
 use crate::error::AppError;
 
@@ -38,14 +39,20 @@ fn router(pool: PgPool) -> Router {
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    tracing_subscriber::fmt::init();
     dotenv().ok();
+    tracing_subscriber::fmt()
+        .with_env_filter(
+            EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")),
+        )
+        .init();
     let pool = db::connect().await?;
+    tracing::info!("connected to database");
     let app = router(pool);
-    let listener = tokio::net::TcpListener::bind(
-        env::var("HEALTH_BIND_ADDRESS").unwrap_or_else(|_| BIND_ADDRESS_FALLBACK.to_string()),
-    )
-    .await?;
+    let bind_address = env::var("HEALTH_BIND_ADDRESS").unwrap_or_else(|_| {
+        tracing::info!("HEALTH_BIND_ADDRESS not set, falling back to {BIND_ADDRESS_FALLBACK}");
+        BIND_ADDRESS_FALLBACK.to_string()
+    });
+    let listener = tokio::net::TcpListener::bind(bind_address).await?;
     tracing::info!("listening at {}", listener.local_addr()?);
     axum::serve(listener, app).await?;
     Ok(())
diff --git a/src/models.rs b/src/models.rs
index 480ef2f..c23dab7 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -87,7 +87,7 @@ pub struct MetricUnitPair {
     pub unit: Unit,
 }
 
-#[derive(Deserialize, Default)]
+#[derive(Deserialize, Default, Debug)]
 #[serde(rename_all = "lowercase")]
 pub enum Order {
     #[default]