ci: [torrust#384] add container healthcheck for index service

For both services:

- The Index API
- The Tracker Stattistics Importer (console cronjob)

An API was added for the Importer. The Importer API has two endpoints:

- GET /health_check -> to get the crobjob status. It only checks that
  is running periodically.
- POST /heartbeat -> used by the cronjob to inform it's alive.

And a new endpoint was added the the Index API:

- GET /health_check -> to check API responsiveness.

Containerfile

@@ -85,7 +85,9 @@ COPY --from=build \
 RUN cargo nextest run --workspace-remap /test/src/ --extract-to /test/src/ --no-run --archive-file /test/torrust-index.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-index /app/bin/torrust-index
+RUN mkdir -p /app/bin/; \
+  cp -l /test/src/target/release/torrust-index /app/bin/torrust-index; \
+  cp -l /test/src/target/release/health_check /app/bin/health_check;
 # RUN mkdir -p /app/lib/; cp -l $(realpath $(ldd /app/bin/torrust-index | 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
 
@@ -99,11 +101,13 @@ ARG TORRUST_INDEX_PATH_CONFIG="/etc/torrust/index/index.toml"
 ARG TORRUST_INDEX_DATABASE_DRIVER="sqlite3"
 ARG USER_ID=1000
 ARG API_PORT=3001
+ARG IMPORTER_API_PORT=3002
 
 ENV TORRUST_INDEX_PATH_CONFIG=${TORRUST_INDEX_PATH_CONFIG}
 ENV TORRUST_INDEX_DATABASE_DRIVER=${TORRUST_INDEX_DATABASE_DRIVER}
 ENV USER_ID=${USER_ID}
 ENV API_PORT=${API_PORT}
+ENV IMPORTER_API_PORT=${IMPORTER_API_PORT}
 ENV TZ=Etc/UTC
 
 EXPOSE ${API_PORT}/tcp
@@ -130,5 +134,6 @@ CMD ["sh"]
 FROM runtime as release
 ENV RUNTIME="release"
 COPY --from=test /app/ /usr/
-# HEALTHCHECK CMD ["/usr/bin/wget", "--no-verbose", "--tries=1", "--spider", "localhost:${API_PORT}/version"]
+HEALTHCHECK --interval=5s --timeout=5s --start-period=3s --retries=3 \  
+  CMD /usr/bin/health_check http://localhost:${API_PORT}/health_check && /usr/bin/health_check http://localhost:${IMPORTER_API_PORT}/health_check || exit 1
 CMD ["/usr/bin/torrust-index"]

contrib/dev-tools/container/e2e/mysql/run-e2e-tests.sh

@@ -25,10 +25,10 @@ echo "Running E2E tests using MySQL ..."
 ./contrib/dev-tools/container/e2e/mysql/e2e-env-up.sh || exit 1
 
 # Wait for conatiners to be healthy
-./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-mysql-1 10 3
-# todo: implement healthchecks for tracker and index and wait until they are healthy
-#wait_for_container torrust-tracker-1 10 3
-#wait_for_container torrust-idx-back-1 10 3
+./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-mysql-1 10 3 || exit 1
+# todo: implement healthchecks for the tracker and wait until it's healthy
+#./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-tracker-1 10 3
+./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh  torrust-index-1 10 3 || exit 1
 sleep 20s
 
 # Just to make sure that everything is up and running

contrib/dev-tools/container/e2e/sqlite/run-e2e-tests.sh

@@ -26,10 +26,10 @@ echo "Running E2E tests using SQLite ..."
 ./contrib/dev-tools/container/e2e/sqlite/e2e-env-up.sh || exit 1
 
 # Wait for conatiners to be healthy
-./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-mysql-1 10 3
-# todo: implement healthchecks for tracker and index and wait until they are healthy
-#wait_for_container torrust-tracker-1 10 3
-#wait_for_container torrust-idx-back-1 10 3
+./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-mysql-1 10 3 || exit 1
+# todo: implement healthchecks for the tracker and wait until it's healthy
+#./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh torrust-tracker-1 10 3
+./contrib/dev-tools/container/functions/wait_for_container_to_be_healthy.sh  torrust-index-1 10 3 || exit 1
 sleep 20s
 
 # Just to make sure that everything is up and running

share/default/config/index.container.mysql.toml

@@ -48,3 +48,4 @@ max_torrent_page_size = 30
 
 [tracker_statistics_importer]
 torrent_info_update_interval = 3600
+port = 3002

share/default/config/index.container.sqlite3.toml

@@ -48,3 +48,4 @@ max_torrent_page_size = 30
 
 [tracker_statistics_importer]
 torrent_info_update_interval = 3600
+port = 3002

share/default/config/index.development.sqlite3.toml

@@ -44,3 +44,4 @@ max_torrent_page_size = 30
 
 [tracker_statistics_importer]
 torrent_info_update_interval = 3600
+port = 3002

src/app.rs

@@ -19,8 +19,8 @@ use crate::services::user::{self, DbBannedUserList, DbUserProfileRepository, DbU
 use crate::services::{proxy, settings, torrent};
 use crate::tracker::statistics_importer::StatisticsImporter;
 use crate::web::api::v1::auth::Authentication;
-use crate::web::api::{start, Version};
-use crate::{mailer, tracker};
+use crate::web::api::Version;
+use crate::{console, mailer, tracker, web};
 
 pub struct Running {
     pub api_socket_addr: SocketAddr,
@@ -46,8 +46,12 @@ pub async fn run(configuration: Configuration, api_version: &Version) -> Running
 
     let settings = configuration.settings.read().await;
 
+    // From [database] config
     let database_connect_url = settings.database.connect_url.clone();
-    let torrent_info_update_interval = settings.tracker_statistics_importer.torrent_info_update_interval;
+    // From [importer] config
+    let importer_torrent_info_update_interval = settings.tracker_statistics_importer.torrent_info_update_interval;
+    let importer_port = settings.tracker_statistics_importer.port;
+    // From [net] config
     let net_ip = "0.0.0.0".to_string();
     let net_port = settings.net.port;
 
@@ -153,29 +157,18 @@ pub async fn run(configuration: Configuration, api_version: &Version) -> Running
         ban_service,
     ));
 
-    // Start repeating task to import tracker torrent data and updating
+    // Start cronjob to import tracker torrent data and updating
     // seeders and leechers info.
-
-    let weak_tracker_statistics_importer = Arc::downgrade(&tracker_statistics_importer);
-
-    let tracker_statistics_importer_handle = tokio::spawn(async move {
-        let interval = std::time::Duration::from_secs(torrent_info_update_interval);
-        let mut interval = tokio::time::interval(interval);
-        interval.tick().await; // first tick is immediate...
-        loop {
-            interval.tick().await;
-            if let Some(tracker) = weak_tracker_statistics_importer.upgrade() {
-                drop(tracker.import_all_torrents_statistics().await);
-            } else {
-                break;
-            }
-        }
-    });
+    let tracker_statistics_importer_handle = console::tracker_statistics_importer::start(
+        importer_port,
+        importer_torrent_info_update_interval,
+        &tracker_statistics_importer,
+    );
 
     // Start API server
+    let running_api = web::api::start(app_data, &net_ip, net_port, api_version).await;
 
-    let running_api = start(app_data, &net_ip, net_port, api_version).await;
-
+    // Full running application
     Running {
         api_socket_addr: running_api.socket_addr,
         api_server: running_api.api_server,

src/bin/health_check.rs

@@ -0,0 +1,37 @@
+//! Minimal `curl` or `wget` to be used for container health checks.
+//!
+//! It's convenient to avoid using third-party libraries because:
+//!
+//! - They are harder to maintain.
+//! - They introduce new attack vectors.
+use std::{env, process};
+
+#[tokio::main]
+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 health_check http://localhost:3002/health_check");
+        std::process::exit(1);
+    }
+
+    println!("Health check ...");
+
+    let url = &args[1].clone();
+
+    match reqwest::get(url).await {
+        Ok(response) => {
+            if response.status().is_success() {
+                println!("STATUS: {}", response.status());
+                process::exit(0);
+            } else {
+                println!("Non-success status received.");
+                process::exit(1);
+            }
+        }
+        Err(err) => {
+            println!("ERROR: {err}");
+            process::exit(1);
+        }
+    }
+}

src/config.rs

@@ -334,12 +334,15 @@ impl Default for Api {
 pub struct TrackerStatisticsImporter {
     /// The interval in seconds to get statistics from the tracker.
     pub torrent_info_update_interval: u64,
+    /// The port the Importer API is listening on. Default to `3002`.
+    pub port: u16,
 }
 
 impl Default for TrackerStatisticsImporter {
     fn default() -> Self {
         Self {
             torrent_info_update_interval: 3600,
+            port: 3002,
         }
     }
 }

src/console/mod.rs

@@ -1 +1,2 @@
 pub mod commands;
+pub(crate) mod tracker_statistics_importer;

src/console/tracker_statistics_importer.rs

@@ -0,0 +1,130 @@
+//! Cronjob to import tracker torrent data and updating seeders and leechers
+//! info.
+//!
+//! It has two services:
+//!
+//! - The importer which is the cronjob executed at regular intervals.
+//! - The importer API.
+//!
+//! The cronjob sends a heartbeat signal to the API each time it is executed.
+//! The last heartbeat signal time is used to determine whether the cronjob was
+//! executed successfully or not. The API has a `health_check` endpoint which is
+//! used when the application is running in containers.
+use std::sync::{Arc, Mutex};
+
+use axum::extract::State;
+use axum::routing::{get, post};
+use axum::{Json, Router};
+use chrono::{DateTime, Utc};
+use log::{error, info};
+use serde_json::{json, Value};
+use tokio::task::JoinHandle;
+
+use crate::tracker::statistics_importer::StatisticsImporter;
+
+const IMPORTER_API_IP: &str = "127.0.0.1";
+
+#[derive(Clone)]
+struct ImporterState {
+    /// Shared variable to store the timestamp of the last heartbeat sent
+    /// by the cronjob.
+    pub last_heartbeat: Arc<Mutex<DateTime<Utc>>>,
+    /// Interval between importation executions
+    pub torrent_info_update_interval: u64,
+}
+
+pub fn start(
+    importer_port: u16,
+    torrent_info_update_interval: u64,
+    tracker_statistics_importer: &Arc<StatisticsImporter>,
+) -> JoinHandle<()> {
+    let weak_tracker_statistics_importer = Arc::downgrade(tracker_statistics_importer);
+
+    tokio::spawn(async move {
+        info!("Tracker statistics importer launcher started");
+
+        // Start the Importer API
+
+        let _importer_api_handle = tokio::spawn(async move {
+            let import_state = Arc::new(ImporterState {
+                last_heartbeat: Arc::new(Mutex::new(Utc::now())),
+                torrent_info_update_interval,
+            });
+
+            let app = Router::new()
+                .route("/", get(|| async { Json(json!({})) }))
+                .route("/health_check", get(health_check_handler))
+                .with_state(import_state.clone())
+                .route("/heartbeat", post(heartbeat_handler))
+                .with_state(import_state);
+
+            let addr = format!("{IMPORTER_API_IP}:{importer_port}");
+
+            info!("Tracker statistics importer API server listening on http://{}", addr);
+
+            axum::Server::bind(&addr.parse().unwrap())
+                .serve(app.into_make_service())
+                .await
+                .unwrap();
+        });
+
+        // Start the Importer cronjob
+
+        info!("Tracker statistics importer cronjob starting ...");
+
+        let interval = std::time::Duration::from_secs(torrent_info_update_interval);
+        let mut interval = tokio::time::interval(interval);
+
+        interval.tick().await; // first tick is immediate...
+
+        loop {
+            interval.tick().await;
+
+            info!("Running tracker statistics importer ...");
+
+            if let Err(e) = send_heartbeat(importer_port).await {
+                error!("Failed to send heartbeat from importer cronjob: {}", e);
+            }
+
+            if let Some(tracker) = weak_tracker_statistics_importer.upgrade() {
+                drop(tracker.import_all_torrents_statistics().await);
+            } else {
+                break;
+            }
+        }
+    })
+}
+
+/// Endpoint for container health check.
+async fn health_check_handler(State(state): State<Arc<ImporterState>>) -> Json<Value> {
+    let margin_in_seconds = 10;
+    let now = Utc::now();
+    let last_heartbeat = state.last_heartbeat.lock().unwrap();
+
+    if now.signed_duration_since(*last_heartbeat).num_seconds()
+        <= (state.torrent_info_update_interval + margin_in_seconds).try_into().unwrap()
+    {
+        Json(json!({ "status": "Ok" }))
+    } else {
+        Json(json!({ "status": "Error" }))
+    }
+}
+
+/// The tracker statistics importer cronjob sends a heartbeat on each execution
+/// to inform that it's alive. This endpoint handles receiving that signal.
+async fn heartbeat_handler(State(state): State<Arc<ImporterState>>) -> Json<Value> {
+    let now = Utc::now();
+    let mut last_heartbeat = state.last_heartbeat.lock().unwrap();
+    *last_heartbeat = now;
+    Json(json!({ "status": "Heartbeat received" }))
+}
+
+/// Send a heartbeat from the importer cronjob to the importer API.
+async fn send_heartbeat(importer_port: u16) -> Result<(), reqwest::Error> {
+    let client = reqwest::Client::new();
+    let url = format!("http://{IMPORTER_API_IP}:{importer_port}/heartbeat");
+
+    client.post(url).send().await?;
+
+    Ok(())
+}

src/lib.rs

@@ -200,6 +200,7 @@
 //!
 //! [tracker_statistics_importer]
 //! torrent_info_update_interval = 3600
+//! port = 3002
 //! ```
 //!
 //! For more information about configuration you can visit the documentation for the [`config`]) module.

src/web/api/v1/contexts/settings/mod.rs

@@ -75,6 +75,7 @@
 //!     },
 //!     "tracker_statistics_importer": {
 //!       "torrent_info_update_interval": 3600
+//!       "port": 3002
 //!     }
 //!   }
 //! }

src/web/api/v1/routes.rs

@@ -4,7 +4,8 @@ use std::sync::Arc;
 
 use axum::extract::DefaultBodyLimit;
 use axum::routing::get;
-use axum::Router;
+use axum::{Json, Router};
+use serde_json::{json, Value};
 use tower_http::compression::CompressionLayer;
 use tower_http::cors::CorsLayer;
 
@@ -34,7 +35,8 @@ pub fn router(app_data: Arc<AppData>) -> Router {
         .nest("/proxy", proxy::routes::router(app_data.clone()));
 
     let router = Router::new()
-        .route("/", get(about_page_handler).with_state(app_data))
+        .route("/", get(about_page_handler).with_state(app_data.clone()))
+        .route("/health_check", get(health_check_handler).with_state(app_data))
         .nest(&format!("/{API_VERSION_URL_PREFIX}"), v1_api_routes);
 
     let router = if env::var(ENV_VAR_CORS_PERMISSIVE).is_ok() {
@@ -45,3 +47,8 @@ pub fn router(app_data: Arc<AppData>) -> Router {
 
     router.layer(DefaultBodyLimit::max(10_485_760)).layer(CompressionLayer::new())
 }
+
+/// Endpoint for container health check.
+async fn health_check_handler() -> Json<Value> {
+    Json(json!({ "status": "Ok" }))
+}

tests/common/contexts/settings/mod.rs

@@ -82,6 +82,7 @@ pub struct Api {
 #[derive(Deserialize, Serialize, PartialEq, Debug, Clone)]
 pub struct TrackerStatisticsImporter {
     pub torrent_info_update_interval: u64,
+    port: u16,
 }
 
 impl From<DomainSettings> for Settings {
@@ -185,6 +186,7 @@ impl From<DomainTrackerStatisticsImporter> for TrackerStatisticsImporter {
     fn from(tracker_statistics_importer: DomainTrackerStatisticsImporter) -> Self {
         Self {
             torrent_info_update_interval: tracker_statistics_importer.torrent_info_update_interval,
+            port: tracker_statistics_importer.port,
         }
     }
 }