Hands-On Microservices with Rust

The main function

In the main function implementation, we create a Runtime instance, which we will use for database queries and to process HTTP requests. Look at the following code:

pub fn main() -> Result<(), Error> {    let mut runtime = Runtime::new()?;    let handshake = tokio_postgres::connect("postgres://postgres@localhost:5432", NoTls);    let (mut client, connection) = runtime.block_on(handshake)?;    runtime.spawn(connection.map_err(drop));    // ...}

We create a Runtime instance. After that, we can create a new database connection by calling the connect function of the tokio-postgres crate. It returns a Future that we have to execute immediately. To run a Future, we will use the same Runtime we have already created. Runtime has the block_on method, ...