Create web service that sends a request to github api

Cargo.toml

[package]
name = "rocket_reqw"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rocket = "0.4"
serde = {version = "1", features = ["derive"]}
serde_json = "1"
reqwest = {version = "0.11", features = ["blocking", "native-tls", "json"]}

rocket_reqwest.rs

// Author: Ugo Varetto
// Updated version of: https://www.shawntabrizi.com/code/combining-rocket-with-reqwest-to-call-an-api-with-rust/
// Also returns JSON record for valid users.

#![feature(decl_macro)]

use rocket::http::RawStr;
use reqwest::blocking::Client;
use reqwest;
use std::time::Duration;
use serde_json;
use serde_json::Value;

#[macro_use] extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Navigate to http://localhost:8000/check/<type your GitHub name here> to check that everything is working!"
}

#[get("/check/<user>")]
fn check(user: &RawStr) -> Result<String, Box<dyn std::error::Error>> {
    let request_url = format!("https://api.github.com/users/{}", user);
    let client = Client::builder()
        .use_native_tls()
        .timeout(Duration::new(5, 0))
        // without user agent it returns 403
        .user_agent("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.81 Safari/537.36")
        .build()?;
    let resp = client.get(request_url).send()?;
    if resp.status().is_success() {
        let pp  = if let Ok(r) = resp.text() {
            let j: Value = serde_json::from_str(r.as_str())?;
            serde_json::to_string_pretty(&j)?
        } else {String::new()};
        Ok(format!("\"{}\" is a user\n\n{}", user, pp))

    }
    else { Ok(format!("\"{}\" is NOT a user", user))}
    
}


fn main() -> Result<(), Box<dyn std::error::Error>> {
    rocket::ignite().mount("/", routes![index, check]).launch();
    Ok(())
}