DEV Community: Wojciech Wernicki

#TIL WebAPI: Intl.NumberFormat

Wojciech Wernicki — Mon, 31 Jul 2023 15:00:00 +0000

The Intl object is the namespace for the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting. The Intl object provides access to several constructors as well as functionality common to the internationalization constructors and other language sensitive functions.¹

Recently I found very handful function for formatting numbers, currency or units — Intl.NumberFormat, which formats values for given language and region.

Documentation: Intl.NumberFormat on MDN

Sources:

Image of JavaScript logotype used in thumbnail is licensed on MIT license, author: Christopher Williams.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl ↩

Migrate React project from create-react-app to Vite.js

Wojciech Wernicki — Sun, 30 Jul 2023 15:30:31 +0000

Recently I had to replace create-react-app with Vite.js in one project at work. This is a thread of what I did to make that work:

Remove CRA & install Vite.js

This is pretty straight-forward, I uninstalled CRA and installed Vite.js packages. I followed an example for react-ts available at Vite documentation¹.

Add support for tests (Jest, React Testing Library)

That one was tricky, but thanks to 2 articles² ³ on Medium (I will link to privacy-friendly versions) I managed to run tests.

Vite config

95% of config was easy to set up, the only thing I had to search online was how to force Vite into using HTTPS with some sort of certificate. It was possible with vite-plugin-basic-ssl⁴.

All set up!

It took me about an hour to set up Vite.js into desired configuration to allow that specific React+TypeScript project into running. I hope it will also help you to kickstart your migration CRA => Vite.

Add leading zeros to a number in JavaScript

Wojciech Wernicki — Sat, 14 Jan 2023 17:00:00 +0000

As I was looking for a more subtle solution for inserting leading zeros to a number than if (number < 10) return `0${number}`;, I found this answer on StackOverflow, which I want to expand to near-one line code snippet.

TypeScript:

// pad-number.ts
const padNumber = (number: number, leadingZeros: number): string => {
  return `${number < 0 ? "-" : ""}${String(Math.abs(number)).padStart(leadingZeros, '0')}`;
}

JavaScript:

// pad-number.js
const padNumber = (number, leadingZeros) => {
  return `${number < 0 ? "-" : ""}${String(Math.abs(number)).padStart(leadingZeros, '0')}`;
}

[Day 6] Securing MongoDB

Wojciech Wernicki — Wed, 19 Aug 2020 20:11:37 +0000

Hello guys!

After installing MongoDB on my machine, it's time to secure access to databases.

Change default port

In file /etc/mongod.conf in section net I changed value of port from default 27017 to 5652:

...
net:
  port: 5652
...

and restarted service with the command sudo systemctl restart mongod.

Create a user with administrative rights

After I changed default port when I want to access MongoDB in console, I have to provide new port:

mongo --port 5652

After successful access, it's time to create a new user with administrative rights:

use admin

db.createUser(
    {
        user: "JohnDoe",
        password: passwordPrompt(),
        roles: [ { role: "userAdminAnyDatabase", db: "admin" }, "readWriteAnyDatabase" ]
    }
)

After confirmation, I need to pass a new password for the user, all thanks to passwordPrompt. To be sure I can access MongoDB via new user, I exit and log in again with the expended command:

mongo --port 5652 -u JohnDoe -p --authenticationDatabase admin

and type in the password.

Enforcing login credentials

Once again I'm heading into /etc/mongod.conf file, where I should change security section:

...
security:
  authorization: "enabled"
...

and restarted once again service with the command sudo systemctl restart mongod.

From now accessing MongoDB with authorization won't trigger any alert or access denial, but after typing in show dbs nothing will be returned. If I want to see databases, I have to authorize myself the same way after I check if my new account does work.

That was a pretty long process to secure databases. At this moment, I don't want to allow any external access to MongoDB, so it is hidden behind the firewall.

References

Cover image: Photo by Dayne Topkin on Unsplash

[Day 5] Installing MongoDB

Wojciech Wernicki — Tue, 18 Aug 2020 22:19:16 +0000

Hello guys!

After short & unexpected break, I'm back and ready to set up yet another thing on my VPS — today it's a database.

Why MongoDB?

I have two main reasons behind that choice:

I don't have much experience with MongoDB;
Which I want to use with GraphQL, also pretty unknown for me at the moment.

Installing MongoDB

I followed the official tutorial provided by MongoDB, available here. I need to install MongoDB in version 4.0 or above, otherwise, GraphQL won't work. Current documentation for MongoDB suggests installing version 4.4, so I will go with that.

Most important steps of install process:

wget -qO - https://www.mongodb.org/static/pgp/server-4.4.asc | sudo apt-key add - # add Mongo's key to APT

echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu focal/mongodb-org/4.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.4.list # add MongoDB 4.4 to list of APT sources

sudo apt update # update packages

sudo apt install mongodb # install MongoDB

sudo systemctl start mongod # start MongoDB service

sudo systemctl enable mongod # allow MongoDB to self-start after server is rebooted

After all these steps, MongoDB is installed, running in the background and ready to be started after machine reboot. I checked that by typing in mongo into open SSH console.

That's all for today! In the next post I will talk about how I secured database.

References

Cover image: Photo by Jan Antonin Kolar on Unsplash

[Day 4] Installing and configuring nginx

Wojciech Wernicki — Sat, 15 Aug 2020 19:36:04 +0000

Hello guys!

It's time for me to set up a WWW server on my VPS! I will both set up nginx and secure it by adding an SSL certificate.

Installing nginx

This one is pretty straight-forward.

sudo apt update
sudo apt install nginx

Firewall

Next thing is to allow nginx to connect outside the server. I need to update UFW settings. First thing is to check up what nginx rules I should allow connecting through the firewall:

sudo ufw app list
# Output
Available applications:
  Nginx Full
  Nginx HTTP
  Nginx HTTPS
  OpenSSH

I will allow Nginx Full:

sudo ufw allow "Nginx Full"

Now I should be able to see default nginx page when I hit the IP address of my machine:

I will skip here part of configuring a domain for nginx. I followed this Digital Ocean — only step 5.

SSL

I followed instructions from this tutorial on Digital Ocean, all the steps that are written up there. In step 4. I chose that nginx should redirect all requests to secure HTTPS version.

That's all for today's session. In the next one, I want to set up a database. See you tomorrow!

References

Cover image: Photo by NeONBRAND on Unsplash

[Day 3] Additional server securing

Wojciech Wernicki — Fri, 14 Aug 2020 22:12:48 +0000

Hello guys!

Today I want to strengthen the security of my server. I want to make it in two different ways: first using dependency fail2ban, second is to enforce using SSH key when logging in.

`fail2ban`

Fail2ban scans log files (e.g. /var/log/apache/error_log) and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc. (source)

Installation

sudo apt install fail2ban

Configuration

There won't be big changes for my needs, although it's recommended to make a local copy of config files:

sudo cp /etc/fail2ban/fail2ban.conf /etc/fail2ban/fail2ban.local
sudo cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

The only thing I will change in the default configuration of fail2ban is to ban suspicious connections permanently except for 10 minutes. In /etc/fail2ban/jail.conf I changed the value of field bantime to a negative number.

Using SSH key for logging in

I've already had my SSH key, so I will skip part of creating it. For interested people, I will leave a link to the documentation of creating SSH keys in References section.

Configuration

1) Copy SSH key to the server

ssh-copy-id johndoe@XXX.XXX.XXX.XXX -p 12345

ssh-copy-id will scan a computer for local SSH keys and copy them on the server. I had to confirm that I want to copy key by inputting password.

2) Disable login by password

After I was sure that I can log in with my key, I changed SSH configuration in file /etc/ssh/sshd_config:

. . .
PasswordAuthentication no
. . .

After save, I restarted SSH with sudo systemctl restart ssh.

Discussion & suggestions

I would like to ask you, especially when you're more experienced in setting up machines like mine: what should I do to secure my server better? Which dependencies or config should I install/change? Thank you for your comments down below!

References

Cover image: Photo by Jaye Haych on Unsplash

[Day 2] Securing server with firewall

Wojciech Wernicki — Thu, 13 Aug 2020 21:31:35 +0000

Hello guys!

As I mentioned in previous post, today I will begin securing my server. Today's topic is disabling root access and setting up firewall.

Disable `root` and changing default SSH port

This one is very easy to achieve. With nano I edited file /etc/ssh/sshd_config by adding rule:

PermitRootLogin no

Also I learned that you should change port for SSH from default 22. In the same file I entered new value:

Port 12345

After that, SSH service restart is needed by command sudo service ssh restart. Now to log in to the server, I have to specify to which port I want to connect myself:

ssh login@XXX.XXX.XXX.XXX -p 12345

Firewall

Most common dependency for firewall is UFW. It was preinstalled on my machine, so all I have to do is to set up necessary rules.

The list of allowed communication both for IPv4 and IPv6 will be for now:

SSH (only for new port)
HTTP
HTTPS

sudo ufw default deny incoming # by default ban all incoming connections
sudo ufw default allow outgoing # by default allow all outgoing connections
sudo ufw allow 12345 # allow to connect to new SSH port
sudo ufw deny 22 # deny to connect to old SSH port
sudo ufw allow http # allow to connect with HTTP connection (port 80)
sudo ufw allow https # allow to connect with HTTP connection (port 443)
sudo ufw enable # enable firewall

And very basic server securing is done! Tomorrow I will give a try with some other dependencies to prevent unauthorized access to my machine.

References

Cover image: Photo by Viktor Forgacs on Unsplash

[Day 1] Initial login to the server

Wojciech Wernicki — Wed, 12 Aug 2020 21:11:47 +0000

Hello guys!

Today is my very first day of my challenge. I'm going to log in to my server for first time and configure all necessary settings: updating server's dependencies and setting up user's permissions.

Update

After logging in, the very first thing you have to do is make sure all dependencies are up to date. For updating in Ubuntu there are two commands:

apt update
apt upgrade

If you're getting error related to permissions, because you're not logged in as root, put sudo before each command.

Optionally, you can remove outdated packages by running command apt autoremove, which I did.

New user

Using root account on daily basis is not the best move as it is the most powerful one on the machine, especially when you want to use it from SSH. I need to create new user that will have administrative rights.

I recommend you to use password manager for keeping your login informations. My first choice for storing passwords for free is KeePass.

To create new user, I typed in:

adduser johndoe

First I entered password and repeated it, then skipped all remaining fields and confirmed them. Second step of creating user is to grant permissions.

usermod -aG sudo johndoe

That's it! For confirmation, I logged in to new account and run sudo reboot now command.

In next post I will talk about securing server by setting up firewall and disable root access from ssh. See you tomorrow!

References

Digital Ocean documentation

Cover image: Photo by Markus Spiske on Unsplash

My 100 days of configuring VPS

Wojciech Wernicki — Tue, 11 Aug 2020 21:55:30 +0000

Hello guys!

With this post, I want to start my journey with servers. My main challenge is to configure and maintain my own VPS machine. I'm going to describe how and why install and setup certain packages or optimize my applications and websites.

VPS choice

I picked VPS from OVH. In my opinion they have pretty good and cheap offer for private servers (starting from $3.50/month). I decided to go with "Essential" package that comes with 2 vCores, 4 GB RAM and 80 GB storage, which I consider to be enough for my needs. Also, during ordering server I chose Ubuntu 20.04 as operating system as that is my most favourite and known OS which I used to set up servers in the past.

Why VPS?

My current position is software developer, I specialize in frontend. I have a bunch of ideas I would love to create in the near future, also I wanted to connect this with learning how to set up and maintain private server, as I've forgotten how to do that during past few years.

I hope you will enjoy this series and knowledge that I will share with you. Bear in mind that it won't be my original content, rather compilation of my new knowledge thanks to the Internet. At the end of each post I'm going to leave some links to documentation and sources which I used for each part of this process.

Cover image: Photo by Taylor Vick on Unsplash

DEV Community: Wojciech Wernicki

#TIL WebAPI: Intl.NumberFormat

Migrate React project from create-react-app to Vite.js

Remove CRA & install Vite.js

Add support for tests (Jest, React Testing Library)

Vite config

All set up!

Add leading zeros to a number in JavaScript

TypeScript:

JavaScript:

[Day 6] Securing MongoDB

Change default port

Create a user with administrative rights

Enforcing login credentials

References

[Day 5] Installing MongoDB

Why MongoDB?

Installing MongoDB

References

[Day 4] Installing and configuring nginx

Installing nginx

Firewall

SSL

References

[Day 3] Additional server securing

fail2ban

Installation

Configuration

Using SSH key for logging in

Configuration

Discussion & suggestions

References

[Day 2] Securing server with firewall

Disable root and changing default SSH port

Firewall

References

[Day 1] Initial login to the server

Update

New user

References

My 100 days of configuring VPS

VPS choice

Why VPS?

`fail2ban`

Disable `root` and changing default SSH port