feat: [torrust#508] add container healthcheck for API

Author: josecelano

Containerfile

@@ -85,7 +85,7 @@ COPY --from=build \
 RUN cargo nextest run --workspace-remap /test/src/ --extract-to /test/src/ --no-run --archive-file /test/torrust-tracker.tar.zst
 RUN cargo nextest run --workspace-remap /test/src/ --target-dir-remap /test/src/target/ --cargo-metadata /test/src/target/nextest/cargo-metadata.json --binaries-metadata /test/src/target/nextest/binaries-metadata.json
 
-RUN mkdir -p /app/bin/; cp -l /test/src/target/release/torrust-tracker /app/bin/torrust-tracker
+RUN mkdir -p /app/bin/; cp -l /test/src/target/release/torrust-tracker /app/bin/torrust-tracker; cp -l /test/src/target/release/http_health_check /app/bin/http_health_check
 RUN mkdir -p /app/lib/; cp -l $(realpath $(ldd /app/bin/torrust-tracker | grep "libz\.so\.1" | awk '{print $3}')) /app/lib/libz.so.1
 RUN chown -R root:root /app; chmod -R u=rw,go=r,a+X /app; chmod -R a+x /app/bin
 
@@ -136,5 +136,7 @@ CMD ["sh"]
 FROM runtime as release
 ENV RUNTIME="release"
 COPY --from=test /app/ /usr/
-# HEALTHCHECK CMD ["/usr/bin/wget", "--no-verbose", "--tries=1", "--spider", "localhost:${API_PORT}/version"]
+HEALTHCHECK --interval=5s --timeout=5s --start-period=3s --retries=3 \  
+  CMD /usr/bin/http_health_check http://localhost:${API_PORT}/health_check \
+    || exit 1
 CMD ["/usr/bin/torrust-tracker"]

src/bin/http_health_check.rs

@@ -10,8 +10,8 @@ use std::{env, process};
 async fn main() {
     let args: Vec<String> = env::args().collect();
     if args.len() != 2 {
-        eprintln!("Usage:   cargo run --bin health_check <HEALTH_URL>");
-        eprintln!("Example: cargo run --bin http_health_check http://localhost:1212/api/v1/stats?token=MyAccessToken");
+        eprintln!("Usage:   cargo run --bin http_health_check <HEALTH_URL>");
+        eprintln!("Example: cargo run --bin http_health_check http://127.0.0.1:1212/health_check");
         std::process::exit(1);
     }
 
@@ -34,4 +34,4 @@ async fn main() {
             process::exit(1);
         }
     }
-}
+}

src/servers/apis/routes.rs

@@ -7,25 +7,28 @@
 //! first path segment. For example: `/api/v1/torrents`.
 use std::sync::Arc;
 
+use axum::routing::get;
 use axum::{middleware, Router};
 use tower_http::compression::CompressionLayer;
 
 use super::v1;
+use super::v1::context::health_check::handlers::health_check_handler;
 use crate::tracker::Tracker;
 
 /// Add all API routes to the router.
 #[allow(clippy::needless_pass_by_value)]
 pub fn router(tracker: Arc<Tracker>) -> Router {
     let router = Router::new();
 
-    let prefix = "/api";
+    let api_url_prefix = "/api";
 
-    let router = v1::routes::add(prefix, router, tracker.clone());
+    let router = v1::routes::add(api_url_prefix, router, tracker.clone());
 
     router
         .layer(middleware::from_fn_with_state(
             tracker.config.clone(),
             v1::middlewares::auth::auth,
         ))
+        .route("/health_check", get(health_check_handler))
         .layer(CompressionLayer::new())
 }

src/servers/apis/v1/context/health_check/handlers.rs

@@ -0,0 +1,11 @@
+//! API handlers for the [`stats`](crate::servers::apis::v1::context::health_check)
+//! API context.
+
+use axum::Json;
+
+use super::resources::{Report, Status};
+
+/// Endpoint for container health check.
+pub async fn health_check_handler() -> Json<Report> {
+    Json(Report { status: Status::Ok })
+}

src/servers/apis/v1/context/health_check/mod.rs

@@ -0,0 +1,34 @@
+//! API health check endpoint.
+//!
+//! It is used to check is the service is running. Especially for containers.
+//!
+//! # Endpoints
+//!
+//! - [Health Check](#health-check)
+//!
+//! # Health Check
+//!
+//! `GET /health_check`
+//!
+//! Returns the API status.
+//!
+//! **Example request**
+//!
+//! ```bash
+//! curl "http://127.0.0.1:1212/health_check"
+//! ```
+//!
+//! **Example response** `200`
+//!
+//! ```json
+//! {
+//!     "status": "Ok",
+//!   }
+//! ```
+//!
+//! **Resource**
+//!
+//! Refer to the API [`Stats`](crate::servers::apis::v1::context::stats::resources::health_check)
+//! resource for more information about the response attributes.
+pub mod handlers;
+pub mod resources;

src/servers/apis/v1/context/health_check/resources.rs

@@ -0,0 +1,14 @@
+//! API resources for the [`stats`](crate::servers::apis::v1::context::health_check)
+//! API context.
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, Debug, PartialEq, Eq)]
+pub enum Status {
+    Ok,
+    Error,
+}
+
+#[derive(Serialize, Deserialize, Debug, PartialEq, Eq)]
+pub struct Report {
+    pub status: Status,
+}

src/servers/apis/v1/context/mod.rs

@@ -3,6 +3,7 @@
 //! Each context is a module that contains the API endpoints related to a
 //! specific resource group.
 pub mod auth_key;
+pub mod health_check;
 pub mod stats;
 pub mod torrent;
 pub mod whitelist;

tests/servers/api/v1/client.rs

@@ -101,7 +101,7 @@ impl Client {
     }
 }
 
-async fn get(path: &str, query: Option<Query>) -> Response {
+pub async fn get(path: &str, query: Option<Query>) -> Response {
     match query {
         Some(params) => reqwest::Client::builder()
             .build()

tests/servers/api/v1/contract/context/health_check.rs

@@ -0,0 +1,20 @@
+use torrust_tracker::servers::apis::v1::context::health_check::resources::{Report, Status};
+use torrust_tracker_test_helpers::configuration;
+
+use crate::servers::api::test_environment::running_test_environment;
+use crate::servers::api::v1::client::get;
+
+#[tokio::test]
+async fn health_check_endpoint_should_return_status_ok_if_api_is_running() {
+    let test_env = running_test_environment(configuration::ephemeral()).await;
+
+    let url = format!("http://{}/health_check", test_env.get_connection_info().bind_address);
+
+    let response = get(&url, None).await;
+
+    assert_eq!(response.status(), 200);
+    assert_eq!(response.headers().get("content-type").unwrap(), "application/json");
+    assert_eq!(response.json::<Report>().await.unwrap(), Report { status: Status::Ok });
+
+    test_env.stop().await;
+}

tests/servers/api/v1/contract/context/mod.rs

@@ -1,4 +1,5 @@
 pub mod auth_key;
+pub mod health_check;
 pub mod stats;
 pub mod torrent;
 pub mod whitelist;