Rust_Server 🚀 and Deployment on Heroku

Rust is a low level programming language for high performance and security. Rocket 🚀 is web framework for web development in Rust Language. Heroku is used to deploy Rust web applications.

Link : https://rust-rocket01.herokuapp.com/

- Rust Server

#![feature(proc_macro_hygiene, decl_macro)]

#[macro_use]
extern crate rocket;

use rocket::request::Form;
use rocket::response::content::Html;

First, we need to include rocket framework. rocket:: rocket::Form is used to get data of form on POST request. rocket:: rocket:content::Html is used for returning Html so that our page shows HTML rather than string.

This is get request from which client is make a post request.

#[get("/num")]
fn getRequest()-> Html<String>{
    let h1=format!("
        <form action='/num' method='post'>
            <input type='number' placeholder='Enter number'
                name='number' id='number'>
            <input type='Submit'>
        </form>
    ");
    Html(h1)
}

It shows a form which has input field of type Number and make a post request to the ("/num"), which is the post request url, in action atrbute.

#[derive(FromForm)]
struct Number{
    number : i32,
}

The above code is use to tell rust what fields are contain in our post request data and of which DataType.

#[post("/num", data = "<number>")]
fn recieveRequest(number : Form<Number>) -> Html<String> {
   let h1=format!("
   <p>{}</p>
    ", number.number);
    Html(h1)
}

This code is used when post request (submit button is clicked) is made, the data sent by client is recieved in data='<number>' and then rust use this parameter as argument variable. This variable number has datatype of Form<Number>, 'Number' which is struct.Then we write the html in format!() macro, which is then return as Html<String>.

For More Help, go to Rocket Framework

This site helps a lot in writing your server.

- Deployment

For Linux

1. Heroku Installation

1. First of all, Make a account on Heroku

For deployment of Application, I will recommend Heroku CLI

2. For installation of Heroku CLI, Run this command in your terminal

sudo snap install --classic heroku

3. Verify your installation using this command.

heroku --version 
# heroku/7.0.0 (darwin-x64) node-v8.0.0

4. Login to Heroku Account

heroku login -i

2. Deployment

1. In the root directory of your written application, open terminal and enter this command.

What is root Directory?

myrepo
    |_src
    |   |_main.rs
    |
    |_target
    |_Cargo.toml
    |_Cargo.lock

In this case, myrepo is your root Directory.

Example:

myname@mycomp:~/Documents/myrepo$

Now write this command,

heroku create YourRepoName \
  --buildpack https://github.com/emk/heroku-buildpack-rust.git

2. Now, make these four files namely : Procfile, rust-toolchain, RustConfig, .travis.yml

Procfile

Write this content in your Procfile

web: ROCKET_PORT=$PORT target/release/YourLocalRepoName

like according to example: 
web: ROCKET_PORT=$PORT target/release/myrepo

rust-toolchain

Write this content in your rust-toolchain file

nightly-2020-05-14

As the rocket framework works with rust-nightly version, so we have to tell Heroku that our application works with rust-nightly.

RustConfig

Write this content in your RustConfig file

VERSION=nightly

.travis.yml

Write this content in your .travis.yml file

language: rust
sudo: required
rust:
- nightly
script:
- |
  cargo build &&
  cargo test

3. Your repo structure is something like this.

myrepo
    |_src
    |   |_main.rs
    |
    |_target
    |_Cargo.toml
    |_Cargo.lock
    |_.gitignore
    |_.travis.yml
    |_Procfile
    |_README.md
    |_Rocket.toml
    |_rust-toolchain
    |_RustConfig

4. Now, the last step to deploy your application, run:

heroku config:set ROCKET_ENV=production
git add .
git commit -m 'commitMsg'
git push heroku master

Your application has been deployed 😃😃😃, now you can see your application using url given by heroku 👏👏👏

You have done!! 🚀🚀