DEV Community: Levani (Leo)

Mastering Secure Remote Access with SSH and Mosh

Levani (Leo) — Wed, 24 Jul 2024 20:49:11 +0000

✨ Introductions

In today's digital age, remote access to servers and systems is a crucial aspect of managing and maintaining IT infrastructure. Secure Shell (SSH) and Mosh (Mobile Shell) are powerful tools that provide robust, secure, and responsive remote connectivity. This guide will walk you through the essential steps to install, configure, and optimize SSH and Mosh, ensuring you have a reliable setup for your remote operations.

SSH: The Secure Shell Protocol is a cryptographic network protocol for operating network services securely over an unsecured network.
Mosh is a replacement for interactive SSH terminals. It's more robust and responsive, especially over Wi-Fi, cellular, and long-distance links.

For MacOS and Arch-Linux, replace the file manager commands with the appropriate ones, the rest will be mostly the same.

Step 1: Install

Debian/Ubuntu:

sudo apt install ssh mosh

Step 2: Configurations and Settings

After installing SSH, navigate to the folder that appears in your home directory.

ls ~/.ssh

There you will see:

id_dsa / id_dsa.pub

id_rsa / id_rsa.pub

Look for a file named id_dsa or id_rsa.

And the corresponding file with the .pub extension.
(.pub) is the public key, and the other file is the private key.

If the specified files are absent (or there is no .ssh directory).

For standard generation:

ssh-keygen

For more detailed configuration:

ssh-keygen -t rsa -b 4096 -C "<your_email>@example.com"

To change the passphrase for a key, use the command:

ssh-keygen -p

The program will first ask for the file location to save the key (.ssh/id_rsa).

If you don't want to enter a passphrase every time you use the key, you can leave it empty or use the ssh-agent program.

If you decide to use a passphrase for the private key, it is highly recommended to use the -o option.

Now, each user should send their public key to you or to the person administering the server (assuming your SSH server is already configured to work with public keys). To do this, simply copy the contents of the .pub file and send it via email.

Step 3: Getting Started with SSH

Start the ssh-agent:
```
eval $(ssh-agent -s)
```
Authorize the ssh key:
```
ssh-add ~/.ssh/id_rsa
```
Check the contents:
```
ssh-add -l
```
Remove all keys (Optional):
```
ssh-add -D
```

Step 4: Setting Up Remote Access

Add your public SSH key to the server's 'authorized_keys' file:
```
vi ~/.ssh/authorized_keys
```
Optional:
If your SSH server is running on a non-standard port (443):
```
ssh-copy-id -p 443 <user>@<server>
```
or

If you are using the default port (22):
```
ssh-copy-id <server_name>
```
Add:
- login
- password

Step 5: Disabling passwords for SSH access

Disable password access to the server:
```
sudo vi /etc/ssh/sshd_config
```
Find and modify the following lines to disable password authentication:

'PasswordAuthentication no'
Apply the changes by restarting the SSH service:
```
sudo service ssh restart
```

Step 6: Setting Up an SSH Alias

Open the SSH configuration file:

vi ~/.ssh/config

Add the following configuration to the file:

Host alias
     Hostname alias.<host_name>
     User <user_name>
     Port 22
     ForwardAgent yes
     ServerAliveInterval 60

To connect to the server using Mosh:

mosh --ssh="ssh -p 22" <user>@<server>

To connect as root, use the following command:

ssh -o "User=root" alias

To connect using SSH:

ssh <alias>

To connect using MOSH:

mosh <alias>

GIT Settings (Optional)

To check the current remote URL:

git remote -v

To change the remote URL from HTTPS to SSH:

git remote set-url origin git@ssh:<repository_name>

P.S. I was glad to share my configuration.

GIT guide for juniors

Levani (Leo) — Tue, 23 Jul 2024 18:52:14 +0000

✨ Introductions

This guide is created for beginners to ensure the development and production branches are secure.

🚀 Let's start

1) Get the repository:

First, you need to choose which type of connection to the GitHub repository suits you best.

SSH: Use this if you have it configured locally and the public key added in the (ssh) settings section on the GitHub website.
HTTPS: The basic option using your username and password.

git clone <repository_url>

2) Get all branches:

git fetch --all

3) Move to the dev branch:

git checkout <dev>

4) Create and move to a new branch:

git checkout -b <branch_name>

⚡ The branch name must be the task name.

5) Add changes or Undo changes:

Add changes

git add <file_name>

git add *

Undo changes to certain files if they were not added to git:

git checkout <file_name>

Removes an object from git repository, but not file:

git rm -r --cached <file_name>

⚡ Make sure that files not allowed in the remote repository have not been added.

For example: .env, cache files and temporary files.

6) Apply changes:

git commit -m 'branch_name: list of changes'

7) Push the new branch alongside the one from which you created it:

git push --set-upstream origin <branch_name>

8) Pull changes from a specific remote repository:

git pull origin <branch_name>

P.S. Follow the steps outlined above, and your project repository will remain secure.

SexyVim

Levani (Leo) — Tue, 30 Apr 2024 21:48:00 +0000

🚀 Vim Configuration

Hey, folks! Today I want to share my Vim configuration with you, which makes working with this powerful text editor even more enjoyable and efficient.

✨ GitHub repository ✨

⭐️ Introduction to Vim

Vim (Vi Improved) is a powerful and flexible text editor with extensive customization and extension capabilities. It was originally created as an enhanced version of the classic Vi editor, retaining its efficiency and speed while adding many additional features.

🤔 Why Use Vim?

Efficiency:

By using hotkeys and editing in command mode, Vim allows you to manipulate text without the need for a mouse, increasing productivity.

Flexibility and Customization:

Vim offers extensive customization options, allowing you to adapt it to your individual needs. This includes changing keyboard layouts, configuring color schemes, adding new features through plugins, and more.

Support for Various Programming Languages:

Vim provides broad support for working with different programming languages, thanks to syntax highlighting, auto-completion, and syntax checking.

📝 Description

This configuration is designed for those who are just starting their journey with Vim, as well as for experienced users who want to enhance their Vim experience.

📦 Plugin List

Vundle (gmarik/Vundle.vim): Manages plugins within Vim.

Code/Project Navigation:

NERDTree (scrooloose/nerdtree): A tree explorer plugin for Vim.
Unite.vim (Shougo/unite.vim): Enables navigation between buffers and files.
Tagbar (majutsushi/tagbar): Provides a class/module browser.
SimpylFold (tmhedberg/SimpylFold): Offers code folding.

Other:

vim-airline (vim-airline/vim-airline): Provides a status/tabline for Vim.
vim-airline-themes (vim-airline/vim-airline-themes): Offers themes for vim-airline.
vim-surround (tpope/vim-surround): Helps with working with parentheses, brackets, quotes, XML tags, and more.
indentLine (Yggdroot/indentLine): Adds indent guides.
vim-move (matze/vim-move): Facilitates moving text.

Snippets Support:

vim-snipmate (garbas/vim-snipmate): Manages code snippets.
vim-addon-mw-utils (MarcWeber/vim-addon-mw-utils): Dependency for vim-snipmate.
tlib_vim (tomtom/tlib_vim): Dependency for vim-snipmate.
vim-snippets (honza/vim-snippets): Repository of code snippets.

Languages Support:

syntastic (scrooloose/syntastic): Provides syntax checking for various languages.
vim-commentary (tpope/vim-commentary): Helps comment/uncomment code.
vim-sparkup (mitsuhiko/vim-sparkup): Offers support for Sparkup (XML/jinja/html-django, etc.).
vim-json (elzr/vim-json): Distinct highlighting of keywords vs values, JSON-specific (non-JS) warnings, quote concealing.
css.vim (JulesWang/css.vim): Offers CSS syntax highlighting.
vim-less (groenewege/vim-less): Provides syntax for LESS (dynamic CSS).
vim-javascript (pangloss/vim-javascript): Improves JavaScript indentation and syntax support.
vim-jsbeautify (maksimr/vim-jsbeautify): Formats JavaScript files using js-beautify.
typescript-vim (leafgarland/typescript-vim): Adds TypeScript syntax support.
html5.vim (othree/html5.vim): Provides HTML5 omnicomplete and syntax.
breeze.vim (idanarye/breeze.vim): Offers HTML navigation similar to vim-easymotion, tag matching, highlighting, and DOM navigation.
jedi-vim (davidhalter/jedi-vim): Enhances Python autocompletion in Vim.
python-mode (klen/python-mode): Adds Python support, including PyLint, Rope, Pydoc, breakpoints.
vim-jinja (mitsuhiko/vim-jinja): Adds Jinja support for Vim.
vim-virtualenv (jmcantrell/vim-virtualenv): Offers Virtualenv support in Vim.
vim-cython (tshirtman/vim-cython): Adds Cython support.
Dockerfile.vim (ekalinin/Dockerfile.vim): Provides syntax highlighting for Dockerfiles.
vim-docker-tools (kkvh/vim-docker-tools): Offers Docker-tools.

🔥 Hotkeys

F1: Toggles NERDTree to browse the list of files in the current directory.
F2: Toggles Tagbar to show a class/module browser.
F3: Opens Unite buffer to navigate through currently opened buffers.
F4: Aligns indents in the current code.
F5: Syntastic syntax checking.
F8: Python code check on PEP8.
Ctrl-j: Move block down.
Ctrl-k: Move block up.
Ctrl-z: Undo.
Ctrl-r: Redo.
Ctrl-a: Select all.
Ctrl-s: Saving, also in Insert mode.
Ctrl-Space: Activates autocompletion.
Shift-q: Close current buffer.
Shift-Right: Move to next buffer (->).
Shift-Left: Move to previous buffer (<-).

Additional Settings

The .vimrc file contains various settings for syntax highlighting, code navigation, and other features.
Specific settings are defined for Python, JavaScript, TypeScript, HTML, CSS, SASS, YAML, JSON, and more languages.
Airline theme is set to powerlineish.
Indentation settings are defined for different filetypes.
Various mappings are provided for easier movement, saving, and navigating between buffers and splits.

For more details and specific usage instructions, refer to the comments in the .vimrc file.

This documentation provides an overview of the plugins, settings, hotkeys, and languages supported by the Vundle Vim configuration.
Users can follow the installation instructions and explore the various features and enhancements offered by this configuration.

🚀 Let's Get Started!

I hope this configuration helps you improve your Vim experience. If you have any questions or suggestions, feel free to share them in the comments!