From 5ca3b74e595346fb3c47c432f01319c1458cc1f5 Mon Sep 17 00:00:00 2001
From: Tobie Morgan Hitchcock <tobie@abcum.com>
Date: Thu, 1 Sep 2022 00:28:43 +0100
Subject: [PATCH] Add HTTP /health endpoint for checking database and datastore
 status

Closes #56
---
 src/err/mod.rs    |  3 +++
 src/net/fail.rs   |  9 +++++++++
 src/net/health.rs | 24 ++++++++++++++++++++++++
 src/net/mod.rs    |  3 +++
 4 files changed, 39 insertions(+)
 create mode 100644 src/net/health.rs

diff --git a/src/err/mod.rs b/src/err/mod.rs
index 755acad6..d0857ff9 100644
--- a/src/err/mod.rs
+++ b/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),
 
diff --git a/src/net/fail.rs b/src/net/fail.rs
index eb3f8676..5c5c00ed 100644
--- a/src/net/fail.rs
+++ b/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,
diff --git a/src/net/health.rs b/src/net/health.rs
new file mode 100644
index 00000000..9beb2f12
--- /dev/null
+++ b/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())
+		}
+	}
+}
diff --git a/src/net/mod.rs b/src/net/mod.rs
index 8d9a7be9..4a1d3e2c 100644
--- a/src/net/mod.rs
+++ b/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