Add HTTP /health endpoint for checking database and datastore status

Closes #56

src/err/mod.rs

@@ -23,6 +23,9 @@ pub enum Error {
 	#[error("There was a problem with authentication")]
 	InvalidAuth,
 
+	#[error("There was a problem connecting with the storage engine")]
+	InvalidStorage,
+
 	#[error("There was a problem with the database: {0}")]
 	Db(#[from] DbError),
 

src/net/fail.rs

@@ -25,6 +25,15 @@ pub async fn recover(err: warp::Rejection) -> Result<impl warp::Reply, warp::Rej
 				}),
 				StatusCode::FORBIDDEN,
 			)),
+			Error::InvalidStorage => Ok(warp::reply::with_status(
+				warp::reply::json(&Message {
+					code: 500,
+					details: Some("Health check failed".to_string()),
+					description: Some("The database health check for this instance failed. There was an issue with the underlying storage engine.".to_string()),
+					information: Some(err.to_string()),
+				}),
+				StatusCode::FORBIDDEN,
+			)),
 			_ => Ok(warp::reply::with_status(
 				warp::reply::json(&Message {
 					code: 400,

src/net/health.rs

@@ -0,0 +1,24 @@
+use crate::dbs::DB;
+use crate::err::Error;
+use warp::Filter;
+
+pub fn config() -> impl Filter<Extract = impl warp::Reply, Error = warp::Rejection> + Clone {
+	warp::path("health").and(warp::path::end()).and(warp::get()).and_then(handler)
+}
+
+async fn handler() -> Result<impl warp::Reply, warp::Rejection> {
+	// Get the datastore reference
+	let db = DB.get().unwrap();
+	// Attempt to open a transaction
+	match db.transaction(false, false).await {
+		// The transaction failed to start
+		Err(_) => Err(warp::reject::custom(Error::InvalidStorage)),
+		// The transaction was successfull
+		Ok(mut tx) => {
+			// Cancel the transaction
+			let _ = tx.cancel().await;
+			// Return the response
+			Ok(warp::reply())
+		}
+	}
+}

src/net/mod.rs

@@ -1,6 +1,7 @@
 mod export;
 mod fail;
 mod head;
+mod health;
 mod import;
 mod index;
 mod key;
@@ -28,6 +29,8 @@ pub async fn init() -> Result<(), Error> {
 		.or(version::config())
 		// Status endpoint
 		.or(status::config())
+		// Health endpoint
+		.or(health::config())
 		// Signup endpoint
 		.or(signup::config())
 		// Signin endpoint