Spawn a thread to periodically get SpaceAPI's status string

src/main.rs

@@ -14,6 +14,19 @@ struct Cli {
     delay: u64,
 }
 
+use std::sync::{Arc, Mutex};
+type Body = Arc<Mutex<String>>;
+
 fn main() {
     let cli = Cli::parse();
+
+    let body: Body = Arc::new(Mutex::new(String::new()));
+    std::thread::spawn(move || loop {
+        let str = client::get_prometheus_string(cli.url.clone());
+        let mut lock = body.lock().unwrap();
+        *lock = str;
+        drop(lock);
+
+        std::thread::sleep(std::time::Duration::from_millis(cli.delay * 1000));
+    });
 }