traininingnotes

m 
 Linux Administration Training

ssh based authentication:  https://stackoverflow.com/questions/66452084/ssh-authentication-process

Lab1:
    1) You should know the basic commands

#How to create  a directory

mkdir testing

# How to go inside the directory

cd testing

#Create a empty file

touch readme
#See contents of file

cat readme

#List all file

ls 

ls -ltr

ls -la

# How to come out from directory

cd ..

#Help page of any command
man cat
man ls
man mkdir
----------------

Selinux vs apparomor

https://www.techtarget.com/searchdatacenter/tip/Compare-two-Linux-security-modules-SELinux-vs-AppArmor


Lab
 
#udpate the pacakge list

sudo apt-get update

#Install package
sudo apt-get install apache2

#remove the package
sudo apt-get remove apache2

#Redhat/centos linux dnf

Lab 4:

sudo adduser training

#It will prompt for password.. provide any passowrd

#Login to the user
su training

#try below activty
sudo apt-get update

#It will give an error

training is not in the sudoers file

--------------------

Lab 5:
    
https://github.com/ 

#Press i <insert mode>

training  ALL=(ALL:ALL) ALL

#You need to press esc+:+wq+! (escape colon wq !)

#Now test
su training
sudo apt-get update

------------------
Day2:  07/05/25

lab 1:
    
    https://www.redhat.com/en/blog/introduction-vi-editor
1) If i want to open a file using vi:[ If file is there, it will open that one, or else it will create new file

vi testfile.sh

2) If you want add something, you will enable the insert mode by pressing "i"

3) Then if you want to save it, come out from the insert mode by pressing: esc

4) If you want to save file  :wq+enter

5) If you don't want to save file :q!
    

Lab2:

1) vi test.sh
2) Insert mode using "i"
3) type the below code

#!/bin/bash
ls /tmp
date
echo "Hi i am amit"

4) Save it esc+:+wq

5)
chmod +x test.sh
6)
./test.sh
bash test.sh

#!/bin/bash
package="apache2"
echo -n "Do you want to install the package?(y/n):"
read answer
if[ "$answer" == "y" ]; the
        sudo apt-get update
        sudo apt-get -y $package
eles
    echo "not installing"
fi

---------------------------
Lab2

mkdir gitlearning
cd gitlearning
git --version
git status
git init
git status

---------
Lab3

setup your username and email id

 git config --global user.name amit
 git config --global user.email amit@ow.com
 
touch test.sh
git status
git add test.sh
git status
 git commit -m "firstcommit"
 git log
 git status
 


 Lab link:https://www.openwriteup.com/?page_id=1075
 
 09/05
 
Sure! Here's a cleaned-up version of the Git Bash steps, using an RSA SSH key instead of ed25519 and with no emojis or custom icons.

Git Bash Steps to Generate RSA Key and Upload to GitHub
1. Generate an RSA SSH Key
Open Git Bash and run:
ssh-keygen -trsa -b 4096 -C "your_email@example.com"
 
Press     Enter to accept the default file location: ~/.ssh/id_rsa 
Enter     a passphrase (optional)
Then display and copy the public key:
cat ~/.ssh/id_rsa.pub
2. Add SSH Key to GitHub
 
Go     to https://github.com 
Click     your profile photo, then Settings 
Go     to SSH and GPG keys 
Click     New SSH key 
Paste     the copied public key 
Click     Add SSH key 
3. Create a Repository on GitHub
 
Choose     Public or Private 
Leave     "Initialize this repository with a README" unchecked 
Click     Create repository
4. Set Up Local Repository with Git Bash
cd /path/to/your/projects

Visit     https://github.com/new 
Enter     the repository name, e.g., my-first-repo mkdir my-first-repo
cd my-first-repo
 
git init
touch README.md
git add README.md
git commit -m "Initial commit"
5. Connect to GitHub and Push
Replace your-username with your actual GitHub username:
git remote add origin git@github.com:your-username/my-first-repo.git
git push -u origin master
If your GitHub repository defaults to the main branch instead of master, use:
git branch -M main
git push -u origin main

 
 
 1. L1 - In EC2 Ubuntu Instance Create a new user
and SSH Key pair with an authorized key

https://usercontent.one/wp/www.openwriteup.com/wp-content/uploads/2023/09/aws-instance-1.pdf?media=1728024675

2. L2 - As a Linux root user Create Files/Directory
in the same Instance and change the ownership to
a new user
1. Create a New User
useradd newuser
passwd newuser

2. Create Files and Directories as root
mkdir /opt/mydir
touch /opt/mydir/file1.txt /opt/mydir/file2.txt

3. Change Ownership to the New User
chown -R newuser:newuser /opt/mydir
The -R option applies the change recursively to all contents.

4. Verify Ownership
ls -l /opt/mydir
Expected output:
-rw-r--r-- 1 newuser newuser 0 May  9 12:00 file1.txt
-rw-r--r-- 1 newuser newuser 0 May  9 12:00 file2.txt


3. L3 - In EC2 Ubuntu Instance Create Files and
Directories and Grand R/W/X Access only to the
Owner and User Group

Task: Create Files and Directories on EC2 Ubuntu, Set Permissions for Owner and Group Only
1. SSH into Your EC2 Ubuntu Instance
ssh -i /path/to/your-key.pem ubuntu@your-ec2-public-dns
2. Create a Directory and Files
mkdir /home/ubuntu/projectL3
cd /home/ubuntu/projectL3
 
# Create sample files
touch file1.txt file2.txt
 
# Optional: Create a subdirectory
mkdir subdir
3. Create or Use a User Group
Create a new group (or use an existing one):
sudo groupadd projectgroup
Add current user (ubuntu) to the group:
sudo usermod -aG projectgroup ubuntu
You may need to log out and back in for group changes to take effect.
4. Change Group Ownership
sudo chgrp -R projectgroup /home/ubuntu/projectL3
5. Set Permissions: R/W/X for Owner and Group Only
chmod -R 770 /home/ubuntu/projectL3
Explanation of 770:
 
Owner:     read (r), write (w), execute (x) 
Group:     read (r), write (w), execute (x) 
Others:     no access (---)
6. Verify Permissions
ls -l /home/ubuntu/projectL3
You should see something like:
-rwxrwx--- 1 ubuntu projectgroup 0 May 9 12:00 file1.txt
-rwxrwx--- 1 ubuntu projectgroup 0 May 9 12:00 file2.txt
 

4. L4 - In EC2 Ubuntu Instance install JDK and

sudo apt update

setup JAVA_HOME path environment variable

sudo apt install -y openjdk-17-jdk


export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
export PATH=$JAVA_HOME/bin:$PATH

5. L5 - Create two AWS EC2 Ubuntu Instances to
establish SSH Connection and SCP the files from
one Instance to another instance


6. L6 - Write a Linux Shell Script to Install Git, JDK,
Maven in EC2 Ubuntu Instance
#!/bin/bash
sudo apt-get install git
sudo apt-get install openjdk-17

 13/05

Assignment



cicd-->scm

-- Create a directory
sudo su
mkdir testrepo
-- Convert that directory into git repo
cd testrepo
git init
-- Create a file
touch readme
-- add and commit the file
git config --global user.name=amit
git config --global user.email=a@ow.com
git add .
git commit -m "add"
ssh-keygen -t rsa
cat /root/.ssh/id_rsa.pub

-- Create a remote GitHub repo 
Login to git and create repo

-- Copy the public key from linux box  (cat command) and paste in github

-- Using ssh you need to push code
in your repo click on ssh type and take last three lines

-- Push your code
Copy and paste the last three lines and code will be pushed


Scp https://builtin.com/articles/scp-command

-- AWs codebuild 
 
---
version: 0.2
phases:
  build:
    commands:
      - echo Building the Docker image...
      - docker build -t $IMAGE_NAME .
artifacts:
  files:
    - "**/*"
  discard-paths: yes
env:
  variables:
    IMAGE_NAME: flask-app

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 















































--------------------------------------