Notes

Useful Links:

https://semaphoreci.com/community/tutorials/dockerizing-a-python-django-web-application

sudo apt install ./google-chrome-stable_current_amd64.deb

https://www.freecodecamp.org/news/bash-scripting-tutorial-linux-shell-script-and-command-line-for-beginners/

https://www.freecodecamp.org/news/shell-scripting-crash-course-how-to-write-bash-scripts-in-linux/

user: rhtshahi pass: rhtshahi

git config: https://youtu.be/bc3_FL9zWWs


Linux Basics:
  - File Systems: Understand the hierarchical file system structure of a typical Linux distribution and learn how to navigate it using  
various commands such as `cd`, `ls`, `pwd`, `mkdir`, `rm`, etc.
  - Users and Groups: Learn how to create, delete, and manage users and groups.
  - Processes and Jobs: Get familiar with processes, their lifecycle, process listing, and job management using commands like `ps`, `top`,
and `kill`.
  - Package Management: Master package managers such as `apt` for Debian-based systems or `yum`/`dnf` for Red Hat-based systems. Learn how
to install, update, and remove packages.

Command Line Tools:
  - Text Editors: Learn text editors like Nano, Vi, Vim, or Emacs to edit files on the command line. gedit
(https://itslinuxfoss.com/edit-files-ubuntu-command-line/)
  - Shell Scripting: Understand shell scripting concepts such as variables, conditional statements, loops, and functions. Learn how to  
write simple scripts using Bash.
  - Automation: Explore tools like `cron` for scheduling tasks and `screen`/`tmux` for managing multiple console sessions.

Networking:
  - IP Addresses: Learn about public, private, and loopback IP addresses, as well as subnetting and IPv4 vs IPv6.(https://www.cloudflare.com/learning/network-layer/what-is-a-subnet/)
(https://www.solarwinds.com/resources/it-glossary/subnetting)

(https://kinsta.com/blog/ipv4-vs-ipv6/#:~:text=The%20most%20obvious%20difference%20is,least%20for%20the%20foreseeable%20future).)

  - SSH: Master secure shell (SSH) connections to manage Linux servers remotely using keys and passwordless login.
(https://www.digitalocean.com/community/tutorials/how-to-use-ssh-to-connect-to-a-remote-server)


  - Firewalls: Understand the basics of firewall concepts and configuration using tools like `iptables` or `firewalld`.
(https://www.checkpoint.com/cyber-hub/network-security/what-is-firewall/)

(https://www.howtogeek.com/177621/the-beginners-guide-to-iptables-the-linux-firewall/)

(https://computingforgeeks.com/install-and-use-firewalld-on-ubuntu/)

  - Network Interfaces: Learn how to configure network interfaces, DNS settings, and hostnames.
{https://ubuntu.com/server/docs/network-configuration}


Security:
  - User Access Management: Learn how to control user access, permissions, and authentication methods using `sudo`, password policies, and
access control lists (ACL).
ls -al

File permissions: chmod

Permission level:
u: current user
g: group in which user belong
o: other
a: all

can be done by file owners

For user:
chmod u+r filename (add permissions)
chmod u-r filename (remove permissions)

For group:
chmod g+r filename (add permissions)
chmod g-r filename (remove permissions)

For other:
chmod o+r filename (add permissions)
chmod o-r filename (remove permissions)

For all:
chmod a+r filename (add permissions)
chmod a-r filename (remove permissions)

File ownership: chown, chgrp
(https://youtu.be/0Bs54BsdHu8)

chown -c username filename
chgrp -c groupname filename

Linux File Permission | Linux Access Control List(ACL): getfacl, setfacl
(https://youtu.be/aIIgtFmWfzo)
(https://youtu.be/Et2cvQvIyUY)

getfacl filename
r:read, w:write, x:execute

setfacl -m u:user:rwx file
setfacl -Rm u:user:rwx folder

linux ownership: https://youtu.be/0Bs54BsdHu8
chgrp, chown

linux file permissions: https://youtu.be/HgMHAbg4TUk
chmod


  - Encryption: Explore encryption methods such as SSH keys, SSL/TLS certificates, and file encryption using tools like OpenSSL or GPG.


  - Updates and Patches: Familiarize yourself with software updates and patch management using package managers or configuration  
management tools.
  - Intrusion Detection: Learn about intrusion detection systems (IDS) and log analysis tools like `Logwatch` and `Syslog-ng`.

System Services:
  - Understand how to manage system services, start/stop/restart them using `systemctl`, and monitor their status with tools like  
`systemctl status`.

Backup and recovery:
  - Learn about backups and data recovery methods such as full image backups, file-level backups, and cloud storage solutions.


rohit@rohit-Standard:~$ htop
rohit@rohit-Standard:~$ sudo su
cat /etc/

@includedir /etc/sudoers.d
root@rohit-Standard:/home/rohit# ^C
root@rohit-Standard:/home/rohit# exit

etc/sudoers.d

copying file:
cp: copy paste cp -r for folder
mv: cut paste
rsync: for copying locally and remotely

What is tar?
How to tat/untar?
(https://www.cyberciti.biz/faq/how-to-tar-a-file-in-linux-using-command-line/)



Postgresql:
https://youtu.be/tducLYZzElo

user: postgres
pass: pass1

git:
https://youtu.be/bc3_FL9zWWs
ssh: https://youtu.be/w22huz8lFsA

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