Initial Commit

src/health/mod.rs

@@ -0,0 +1,68 @@
+use chrono::{DateTime, Utc};
+use futures::lock::Mutex;
+use log::info;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+pub type ServiceId = String;
+
+#[derive(Debug)]
+pub enum HealthStatus {
+    /// The service is up and running
+    Up,
+
+    /// The service gave an error when performing the health check
+    Errored,
+
+    /// The service did not respond to the health check
+    Down,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct ServiceConfig {
+    pub url: String,
+    pub mode: HttpHealthCheckMode,
+}
+
+#[derive(Serialize, Deserialize)]
+pub enum HttpHealthCheckMode {
+    /// Expect the server to return a 200 status code. The body is ignored.
+    Check200,
+}
+
+pub struct HealthState {
+    pub health: HashMap<ServiceId, Mutex<Option<HealthStatus>>>,
+    pub config: HealthConfig,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct HealthConfig {
+    pub services: HashMap<ServiceId, ServiceConfig>,
+}
+
+impl HealthState {
+    pub fn new(config: HealthConfig) -> HealthState {
+        HealthState {
+            health: config
+                .services
+                .iter()
+                .map(|(id, _config)| (id.clone(), Mutex::new(None)))
+                .collect(),
+            config,
+        }
+    }
+
+    pub async fn update(&self) {
+        for (id, status) in &self.health {
+            let url = &self.config.services[id].url;
+            info!("service [{}] querying {}", id, url);
+            let new_status = match reqwest::get(url).await {
+                Err(_) => HealthStatus::Down,
+                Ok(response) if response.status().is_success() => HealthStatus::Up,
+                Ok(_response) => HealthStatus::Errored,
+            };
+            info!("service [{}] new status {:?}", id, new_status);
+            *status.lock().await = Some(new_status);
+        }
+    }
+}