feat: add simple health check

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/churn-server/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "churn-server"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow.workspace = true
+tokio.workspace = true
+tracing.workspace = true
+tracing-subscriber.workspace = true
+clap.workspace = true
+dotenv.workspace = true
+axum.workspace = true

crates/churn-server/src/main.rs

@@ -0,0 +1,64 @@
+use std::net::SocketAddr;
+
+use axum::response::IntoResponse;
+use axum::routing::{get, post};
+use axum::Router;
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None, subcommand_required = true)]
+struct Command {
+    #[command(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    Serve {
+        #[arg(env = "SERVICE_HOST", long, default_value = "127.0.0.1:3000")]
+        host: SocketAddr,
+    },
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    dotenv::dotenv().ok();
+    tracing_subscriber::fmt::init();
+
+    let cli = Command::parse();
+
+    match cli.command {
+        Some(Commands::Serve { host }) => {
+            tracing::info!("Starting service");
+
+            let app = Router::new().nest(
+                "/agent",
+                Router::new()
+                    .route("/enroll", post(enroll))
+                    .route("/ping", post(ping))
+                    .route("/events", post(get_tasks)),
+            );
+
+            tracing::info!("listening on {}", host);
+            axum::Server::bind(&host)
+                .serve(app.into_make_service())
+                .await
+                .unwrap();
+        }
+        None => {}
+    }
+
+    Ok(())
+}
+
+async fn enroll() -> impl IntoResponse {
+    todo!()
+}
+
+async fn ping() -> impl IntoResponse {
+    todo!()
+}
+
+async fn get_tasks() -> impl IntoResponse {
+    todo!()
+}