Hands-On Microservices with Rust

Different formats

We need two extra crates: queryst for parsing parameters from the query string, and the serde_cbor crate to support the CBOR serialization format. Add these to your Cargo.toml:

queryst = "2.0" serde_cbor = "0.8"

Also, import them in main.rs:

extern crate queryst;extern crate serde_cbor;

Instead of using serde_json::to_string directly in the handler, we'll move it to a separate function that serializes data depending on the expected format:

fn serialize(format: &str, resp: &RngResponse) -> Result<Vec<u8>, Error> {    match format {        "json" => {            Ok(serde_json::to_vec(resp)?)        },        "cbor" => {            Ok(serde_cbor::to_vec(resp)?)        },        _ => {            Err(format_err!("unsupported format {}", format))        },    }}

In this code, we used a match expression to ...