adduser username 

2. Add this user to sudoers group:

usermod -aG sudo username

3. Switch to this user:

su - username

4. Open the ssh configuration file:

vim /etc/ssh/sshd_config

5. In the line PermitRootLogin yes replace the word Yes with the word No:

PermitRootLogin no

6. In the line #PasswordAuthentication yes replace the word Yes with the word No and uncomment this line:

PasswordAuthentication no

7. Add your id_rsa.pub to autorized_keys (run it from the client):

ssh-copy-id username@remote_host

8. Save the file and restart the service:

sudo service ssh restart

9. Install curl:

sudo apt update && sudo apt install curl -y 

10. Download openvpn-installer:

curl -O https://raw.githubusercontent.com/angristan/openvpn-install/master/openvpn-install.sh

11. Add execution permission:

chmod +x openvpn-install.sh

12. Then run it:

sudo ./openvpn-install.sh

13. Create ssh "bookmark" (run it from the client):

echo "Host dev
     HostName 0.0.0.0
     User username
     Port 22
 " >> ~/.ssh/config

14. Copy *.ovpn files to your PC (run it from the client):

scp dev:~/*.ovpn ~/Downloads/

Firstly we have to set up the scaffold

nest g module user — generate module

nest g controller user — generate controller

If everything is alright you should see the new folder in your src/. It must contain files:

1. user.controller.spec.ts — tests for controller
2. user.controller.ts ­— the controller file (for more information follow the link)
3. user.module.ts — the module file (for more information link)

After that, we can create the service file

nest g service user/user

This command will create a subfolder in your user folder named user. It quite comfortable for me but if you used to flat project structure you can run this command just: nest g service user/

Now let's create DTO and Entity files for user module

touch src/user/user.dto.ts
touch src/user/user.entity.ts
Finally, install necessary packages

yarn add jsonwebtoken @types/jsonwebtoken

yarn add bcrypt @types/bcrypt

Let's describe the user data model

Open user.entity.ts and write something like this:

Line 12 — declare new entity named 'user'
Line 14-15 — create autogenerated column for user id
Line 17-18 — create column to store date user had register
Line 20-24 — the unique column for user id, it needs for decline registration with the same username
Line 27-27 — column for password
Line 29-32 — function witch called before password could store. This function hashes the user's password before we stored it in the database
Line 34-41 ­— this function will return UserObject after registration
Line 43-53 — getter function for JWT token
Line 55-57 — password comparator

Not to forget add your SECRET string into .env file, it should be like:

And import it into user.module:

Describe UserDTO

Create some methods for user module

Open the user cntroller and create register, login and get all users command:

let's implement our service methods

Firstly you could create dummy functions

Now we can implement getAll() function:

We use responseObject(false) because we don't need to get JWT token in this case

Next we must implement login() function:

And finnaly implement register() function:

Create validation function for the Read method

Go to quiz.servise.ts and edit the read() function such as:

Line by line explanation:

1. Declaration of the read() function which takes id with string type.
2. Writing a response from a database to the quiz constant.
3. Checking whether the quiz constant's value is 'null'. The condition will be true if the quiz is undefined or equals to 'null'.
4. Throwing a new exception. It will be handled by our logging interceptor from the previous part. HttpException is the function of two arguments: the first one — a message which will be shown when error threw, second — just server response code like a 404 for Not Found or 200 for OK.
5. "Else" statement.
6. Returning data that we received from the database.

Do the same for Update and Delete methods

Create a class validator

Install the necessary packages:

yarn add class-transformer class-validator

And create file

touch src/shared/validation.pipe.ts

Now just copy code from the official documentation, and write some fixes:

Rows 14-19 — validate did we receive an empty object.
Rows 28-31 ­— pass the errors to logging interceptor.
Rows 41-49 — aggregate all errors into one string.
Rows 50-56 — a function that checks if an object is empty.

Then we have to change our DTO file to be able to validate fields:

Finally, connect your Validation Pipe to the controller:

1. Create folder:
   mkdir src/shared && cd src/shared
2. Create the filter:
   touch http-error.filter.ts
3. Write simple error handler

Include custom error handler as a provider to the app module

Add a logger to this error handler

The next thing that we should do is creating the Logger for our ErrorHandler:

Open your http-error.filter.ts file and type simple logger:

Pay attention, this code must be member of catch() function

Now if we send some incorrect request we should see:

Looks pretty good, but we still don't logging crrect requests.

Let's make interceptor

Create a new file: touch src/shared/logging.interceptor.ts

And write simple logger:

Now we can connect it as a provider to app.module

Check how it works. Start the server and send some correct request, you should get some like this:

Create infrastructure files:

Via NestCLI generate:

1. Module: nest g mo quiz
2. Controller: nest g controller quiz
3. Service: nest g service quiz/quiz

Where `quiz` is the name of your module.

Setup API controller

1. Open quiz.controller.ts and write some CRUD methods:

You should have something like this

2. Open quiz.module.ts and import our TypeORM Model:

3. Open quiz.service.ts and add our Entity Repository:

Implement CRUD methods

Now we can implement our CRUD methods, that we had been initialized before. Let's open quiz.service.ts file and write implementation:

As we can see in lines 16 and 20 we use the data param with type any. That is not accorded to TypeScript guidelines, we must write DTO (Data Transfer Object) to tipizate this param:

Create DTO

Firstly we have to create this file via command: touch src/quiz/quiz.dto.ts

Then open this file and describe our data:

Now we can type param data in quiz.service.ts:

Connect the service to the controller

Now, finally, we can connect our service to the controller. Open quiz.controller.ts and determinate service functions:

Finally, you can start your server and test its functionality

Test

Actually, we must write many tests and mutch documentation for something like Swagger to our API, but not today. In this part, Postman is enough for us. Let's install it:

sudo snap install postman 

In the Postman press "New" button:

On the next step choose "Request":

Next, setup Name for request and Name for collection, and press Save to Collection:

GET readAll()

Finally, we can create our first request:

1. Choose type GET
2. Write address for entry point with format IP : PORT / service
3. Press Send

If everything is alright, you should see the empty array in the response

POST create()

Change Type to POST and create some entry:

1. Change Type of Request
2. Go to tab "Body"
3. Choose "raw" type
4. Set "JSON" format
5. Write your request data. Fields for body you can find in DTO or Entry files

Press Send. And you should see a response like this:

Copy id value, it will be necessary for the next request

PUT update()

Change Type to PUT and edit our entry:

1. Change Type to PUT
2. Change URL according to format URL : PORT / SERVICE / UUID
3. Edit Body data

Press Send. Now response will be different:

DELETE delete()

Change type to DELETE

1. Change Type to DELETE and press Send

The response should be:

Firstly we need to install CLI tools for creating the scaffold.

I use the npm for this because the yarn has a bug with node engine version:

npm i -g @nestjs/cli

After that, we must create a new boilerplate project:

nest new {type your project name here}

This wizard will ask you about which package manager is you prefer:

Which package manager would you ❤️ to use?
>npm
>yarn

I prefer yarn and in this article, I had chosen it.

When installation will be done you will see:

Now we can setting up Prettier:

cd {YourProjectName}
vim .prettierrc

In this file we must wrote something like this:

{
"useTabs": false,
"tabWidth": 2,
"singleQuote": true,
"trailingComma": "all",
"semi": true,
"jsxBracketSameLine": true,
"bracketSpacing": true,
"arrowParens": "avoid"
}

Finally we can start project and have see Hello World message, let's try:

cd {YourProjectName}

yarn run start 

When you will see:

You can check how it's work into your browser on page http://localhost:3000

And now you probably get stuck with :3000, what does it mean? Yeah, it is port of your server, it can be change in src/main.ts file line 6:

It's not beautiful enough, what we have to do if we'll want change it dynamically? Yes, we must pull it into enviroment variable. But how?

The dotenv packagecomes to our aid, let's add it:

yarn add dotenv

and setup it:

touch .env && echo "PORT=4000" > .env

Now we can use environment variables in our project just like this:

What is we have done?

1. Imported package dotenv/config into main.ts
2. Created constant with the value from .env file or, if it's empty, 8080
3. Used it in the function app.listen()

Now we can check this, go to http://localhost:4000 if we have done everything right, we'll see the "Hello World" message.

Not forget to reload your server, if you want use hotreload you have to use yarn run start:dev instead of yarn run start

Looks good, but how we can know witch PORT used now? We have to write a Logger for our server! Open main.ts file and add this string after app.listen() function:

Now, after you start your server you must see message like this:

2. Install packages to using DataBase

JS packages

In order to work with the database, we need to install some packages:

yarn add pg typeorm @nestjs/typeorm

OS packages

For development we also need Postgres Server and PgAdmin tool, if you are use Ubuntu 18.04 you have to install it this way:

1. cd /etc/apt/sources.list.d/
2. sudo touch pgdg.list
3. echo "deb http://apt.postgresql.org/pub/repos/apt/ bionic-pgdg main" > pgdg.list
4. wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
5. sudo apt-get update
6. sudo apt install postgresql-11 postgresql-client-11 pgadmin4

For another OS check this page.

After installation instruction:

1. Edit the pg_hba.conf file: sudo vim /etc/postgresql/11/main/pg_hba.conf
2. Change the line local all postgres peer to local all postgres trust
3. Restart postgresql service: sudo service postgresql restart
4. Log in into DB and change password:
1. psql -U postgres
2. In the postgres=# prompt: ALTER USER postgres with password ‘new-password’;
5. Revert the changes:
1. sudo vim /etc/postgresql/11/main/pg_hba.conf change line from trust to md5
2. Restart postgresql service: sudo service postgresql restart

3. Setup DataBase

Create a new DataBase

1. Login to Postgres
• psql -U postgres
2. Create a new DB
• create database quiz;
• \q - to quit from psql

Connect the DataBase to your project

Create ORM config file

• touch ormconfig.js
• Edit this file as follows

Where fields "host", "username", "password", "database" is your credentials to database which can set in .env file

• Set credentials in .env file:

Import ORM module:

• Go to file src/app.module.ts
• Add the following lines:

Start working with DB

Create entities

1. Create entnities structure
• mkdir src/quiz
• cd src/quiz/ && touch quiz.entity.ts
2. Edit quiz.entity.ts as follow:

Check if it work

Star your server via yarn run start . Then you must see output like that:

Now browse the DB:

• psql -U postgres - connect to db server
• \c quiz - open db called quiz
• \dt - describe tables within

If everything is ok, you should see:

sudo curl -L https://github.com/docker/compose/releases/download/1.21.2/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose

Возможно, потребуется установка curl

sudo apt install curl

2. Дать права на исполнение

sudo chmod +x /usr/local/bin/docker-compose

3. Протестировать

docker-compose --version

4. Создать папку под проект и перейти в нее

sudo mkdir ~/wordpress && cd ~/wordpress

5. Создать файл docker-compose.yml и добавить в него конфиг

sudo nano docker-compose.yml


version: '3.3'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
volumes:
    db_data:

6. Собрать и поднять контейнер

sudo docker-compose up -d

7. Установить Wordpress

Перейти на http://127.0.0.1:8000