Integrating token manager with axum

main.rs

pub type SharedTokenManager = Arc<Mutex<TokenManager>>;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    ...
    
    let shared_token_manager = {
        let manager = TokenManager::new(&config.google_application_credentials)
            .context("Failed to create token manager")?;
        SharedTokenManager::new(Mutex::new(manager))
    };

    let app = Router::new()
    	.layer(Extension(shared_token_manager))

    ...
}
	
fun request(Extension(mut token_manager): Extension<SharedTokenManager>) {
	let mut token_manager_guard = token_manager.lock().await;
	
	let auth_token = token_manager_guard.get_token().await?;
	// use auth_token to send fcm message
}