$ -weight: 500;">apt -weight: 500;">update # Update the package index (local DB of available repos) -weight: 500;">apt -weight: 500;">upgrade # Upgrade installed packages to latest versions -weight: 500;">apt -weight: 500;">install <pkg_name> # Install a package -weight: 500;">apt -weight: 500;">remove <pkg_name> # Remove a package -weight: 500;">apt search <pkg_name> # Search for a package -weight: 500;">apt show <pkg_name> # Show package details -weight: 500;">apt list --installed # List all installed packages -weight: 500;">apt -weight: 500;">update # Update the package index (local DB of available repos) -weight: 500;">apt -weight: 500;">upgrade # Upgrade installed packages to latest versions -weight: 500;">apt -weight: 500;">install <pkg_name> # Install a package -weight: 500;">apt -weight: 500;">remove <pkg_name> # Remove a package -weight: 500;">apt search <pkg_name> # Search for a package -weight: 500;">apt show <pkg_name> # Show package details -weight: 500;">apt list --installed # List all installed packages -weight: 500;">apt -weight: 500;">update # Update the package index (local DB of available repos) -weight: 500;">apt -weight: 500;">upgrade # Upgrade installed packages to latest versions -weight: 500;">apt -weight: 500;">install <pkg_name> # Install a package -weight: 500;">apt -weight: 500;">remove <pkg_name> # Remove a package -weight: 500;">apt search <pkg_name> # Search for a package -weight: 500;">apt show <pkg_name> # Show package details -weight: 500;">apt list --installed # List all installed packages uname -a # Full system info (kernel name, version, architecture) lsb_release -a # Distribution-specific info cat /etc/os-release # OS release details uname -a # Full system info (kernel name, version, architecture) lsb_release -a # Distribution-specific info cat /etc/os-release # OS release details uname -a # Full system info (kernel name, version, architecture) lsb_release -a # Distribution-specific info cat /etc/os-release # OS release details wc -l devops_course_outline.txt # ^ ^ ^ # | | +-- argument (what to operate on) # | +------- option (modifies behavior, starts with - or --) # +------------ command (program to execute) wc -l devops_course_outline.txt # ^ ^ ^ # | | +-- argument (what to operate on) # | +------- option (modifies behavior, starts with - or --) # +------------ command (program to execute) wc -l devops_course_outline.txt # ^ ^ ^ # | | +-- argument (what to operate on) # | +------- option (modifies behavior, starts with - or --) # +------------ command (program to execute) -weight: 600;">sudo ls -la /root # List root's home directory with elevated privileges -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx # Install software (needs root) -weight: 600;">sudo ls -la /root # List root's home directory with elevated privileges -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx # Install software (needs root) -weight: 600;">sudo ls -la /root # List root's home directory with elevated privileges -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx # Install software (needs root) cd /usr/bin # Absolute path cd ../usr/bin # Relative path cd /usr/bin # Absolute path cd ../usr/bin # Relative path cd /usr/bin # Absolute path cd ../usr/bin # Relative path touch newfile.txt # Create empty file (or -weight: 500;">update timestamp) touch -t 12091600 file.txt # Set specific timestamp (Dec 9, 4PM) echo "hello" > file.txt # Write to file (OVERWRITES!) echo "world" >> file.txt # Append to file cp source.txt dest.txt # Copy file mv old.txt new.txt # Rename/move file rm file.txt # Delete file rm -rf directory/ # Force delete directory and contents touch newfile.txt # Create empty file (or -weight: 500;">update timestamp) touch -t 12091600 file.txt # Set specific timestamp (Dec 9, 4PM) echo "hello" > file.txt # Write to file (OVERWRITES!) echo "world" >> file.txt # Append to file cp source.txt dest.txt # Copy file mv old.txt new.txt # Rename/move file rm file.txt # Delete file rm -rf directory/ # Force delete directory and contents touch newfile.txt # Create empty file (or -weight: 500;">update timestamp) touch -t 12091600 file.txt # Set specific timestamp (Dec 9, 4PM) echo "hello" > file.txt # Write to file (OVERWRITES!) echo "world" >> file.txt # Append to file cp source.txt dest.txt # Copy file mv old.txt new.txt # Rename/move file rm file.txt # Delete file rm -rf directory/ # Force delete directory and contents find /var/log -name "*.log" # Find all .log files in /var/log find /usr -name gcc # Find files/dirs named gcc find /usr -type d -name gcc # Find only DIRECTORIES named gcc find /usr -type f -name gcc # Find only regular FILES named gcc find / -size +10M # Find files larger than 10MB find / -size 0 # Find empty files find / -mtime 3 # Files modified 3 days ago find / -user root # Files owned by root find -name "*.jpg" -exec rm {} ';' # Find and DELETE all .jpg files find / -size +10M -exec command {} ';' # Find large files and run command find /var/log -name "*.log" # Find all .log files in /var/log find /usr -name gcc # Find files/dirs named gcc find /usr -type d -name gcc # Find only DIRECTORIES named gcc find /usr -type f -name gcc # Find only regular FILES named gcc find / -size +10M # Find files larger than 10MB find / -size 0 # Find empty files find / -mtime 3 # Files modified 3 days ago find / -user root # Files owned by root find -name "*.jpg" -exec rm {} ';' # Find and DELETE all .jpg files find / -size +10M -exec command {} ';' # Find large files and run command find /var/log -name "*.log" # Find all .log files in /var/log find /usr -name gcc # Find files/dirs named gcc find /usr -type d -name gcc # Find only DIRECTORIES named gcc find /usr -type f -name gcc # Find only regular FILES named gcc find / -size +10M # Find files larger than 10MB find / -size 0 # Find empty files find / -mtime 3 # Files modified 3 days ago find / -user root # Files owned by root find -name "*.jpg" -exec rm {} ';' # Find and DELETE all .jpg files find / -size +10M -exec command {} ';' # Find large files and run command locate zip # Fast search using pre-built database # Database is updated by 'updatedb' (runs daily automatically) locate zip # Fast search using pre-built database # Database is updated by 'updatedb' (runs daily automatically) locate zip # Fast search using pre-built database # Database is updated by 'updatedb' (runs daily automatically) which python3 # Shows path of executable: /usr/bin/python3 whereis python3 # Shows binary, source, and man page locations which python3 # Shows path of executable: /usr/bin/python3 whereis python3 # Shows binary, source, and man page locations which python3 # Shows path of executable: /usr/bin/python3 whereis python3 # Shows binary, source, and man page locations echo "hello" > file.txt # Redirect stdout to file (overwrite) echo "world" >> file.txt # Redirect stdout to file (append) command < input.txt # Feed file as stdin to command command 2> errors.txt # Redirect stderr to file command > out.txt 2>&1 # Redirect BOTH stdout AND stderr to file cat /etc/passwd | wc -l # Pipe: send output of cat as input to wc cat /etc/passwd | cut -d: -f1 | sort | uniq # Chain multiple pipes echo "hello" > file.txt # Redirect stdout to file (overwrite) echo "world" >> file.txt # Redirect stdout to file (append) command < input.txt # Feed file as stdin to command command 2> errors.txt # Redirect stderr to file command > out.txt 2>&1 # Redirect BOTH stdout AND stderr to file cat /etc/passwd | wc -l # Pipe: send output of cat as input to wc cat /etc/passwd | cut -d: -f1 | sort | uniq # Chain multiple pipes echo "hello" > file.txt # Redirect stdout to file (overwrite) echo "world" >> file.txt # Redirect stdout to file (append) command < input.txt # Feed file as stdin to command command 2> errors.txt # Redirect stderr to file command > out.txt 2>&1 # Redirect BOTH stdout AND stderr to file cat /etc/passwd | wc -l # Pipe: send output of cat as input to wc cat /etc/passwd | cut -d: -f1 | sort | uniq # Chain multiple pipes kill -SIGKILL <PID> # Force kill a process (same as kill -9) kill -9 <PID> # Force kill by PID node server.js & # Run process in background (& suffix) lsof -i :80 # Find what process is using port 80 kill -SIGKILL <PID> # Force kill a process (same as kill -9) kill -9 <PID> # Force kill by PID node server.js & # Run process in background (& suffix) lsof -i :80 # Find what process is using port 80 kill -SIGKILL <PID> # Force kill a process (same as kill -9) kill -9 <PID> # Force kill by PID node server.js & # Run process in background (& suffix) lsof -i :80 # Find what process is using port 80 man apache2 # Full manual page for a command man -k compress # Search man pages by keyword info make # GNU Info documentation (alternative to man) command --help # Quick help/usage summary (fastest option) man apache2 # Full manual page for a command man -k compress # Search man pages by keyword info make # GNU Info documentation (alternative to man) command --help # Quick help/usage summary (fastest option) man apache2 # Full manual page for a command man -k compress # Search man pages by keyword info make # GNU Info documentation (alternative to man) command --help # Quick help/usage summary (fastest option) -rw-r--r-- 1 sajid devops_students 13 2022-05-11 08:29 lecture.txt ^^^^^^^^^ ^ ^ | | +-- group owner | +-------- file owner (user) +-------------------- permission string First char: - = file, d = directory, l = symlink Next 9 chars: rwx for user | rwx for group | rwx for others Example: -rw-r--r-- means: User: rw- (read + write) = 4+2+0 = 6 Group: r-- (read only) = 4+0+0 = 4 Other: r-- (read only) = 4+0+0 = 4 Octal: 644 -rw-r--r-- 1 sajid devops_students 13 2022-05-11 08:29 lecture.txt ^^^^^^^^^ ^ ^ | | +-- group owner | +-------- file owner (user) +-------------------- permission string First char: - = file, d = directory, l = symlink Next 9 chars: rwx for user | rwx for group | rwx for others Example: -rw-r--r-- means: User: rw- (read + write) = 4+2+0 = 6 Group: r-- (read only) = 4+0+0 = 4 Other: r-- (read only) = 4+0+0 = 4 Octal: 644 -rw-r--r-- 1 sajid devops_students 13 2022-05-11 08:29 lecture.txt ^^^^^^^^^ ^ ^ | | +-- group owner | +-------- file owner (user) +-------------------- permission string First char: - = file, d = directory, l = symlink Next 9 chars: rwx for user | rwx for group | rwx for others Example: -rw-r--r-- means: User: rw- (read + write) = 4+2+0 = 6 Group: r-- (read only) = 4+0+0 = 4 Other: r-- (read only) = 4+0+0 = 4 Octal: 644 chmod 644 file.txt # rw-r--r-- (standard file permission) chmod 755 directory/ # rwxr-xr-x (standard directory permission) chmod 700 secret.txt # rwx------ (owner only, full access) chmod 666 file.txt # rw-rw-rw- (everyone can read/write) chmod +x script.sh # Add execute permission for everyone chmod u+x script.sh # Add execute for user only chmod g-w file.txt # Remove write from group chmod o-rwx file.txt # Remove all permissions from others chmod 644 file.txt # rw-r--r-- (standard file permission) chmod 755 directory/ # rwxr-xr-x (standard directory permission) chmod 700 secret.txt # rwx------ (owner only, full access) chmod 666 file.txt # rw-rw-rw- (everyone can read/write) chmod +x script.sh # Add execute permission for everyone chmod u+x script.sh # Add execute for user only chmod g-w file.txt # Remove write from group chmod o-rwx file.txt # Remove all permissions from others chmod 644 file.txt # rw-r--r-- (standard file permission) chmod 755 directory/ # rwxr-xr-x (standard directory permission) chmod 700 secret.txt # rwx------ (owner only, full access) chmod 666 file.txt # rw-rw-rw- (everyone can read/write) chmod +x script.sh # Add execute permission for everyone chmod u+x script.sh # Add execute for user only chmod g-w file.txt # Remove write from group chmod o-rwx file.txt # Remove all permissions from others -weight: 600;">sudo chown root:root file.txt # Change owner AND group to root -weight: 600;">sudo chown daniyal file.txt # Change owner only -weight: 600;">sudo chown daniyal:www-data file.txt # Change owner to daniyal, group to www-data -weight: 600;">sudo chown -R www-data:www-data /var/www/html/ # Recursive (all files inside) -weight: 600;">sudo chown root:root file.txt # Change owner AND group to root -weight: 600;">sudo chown daniyal file.txt # Change owner only -weight: 600;">sudo chown daniyal:www-data file.txt # Change owner to daniyal, group to www-data -weight: 600;">sudo chown -R www-data:www-data /var/www/html/ # Recursive (all files inside) -weight: 600;">sudo chown root:root file.txt # Change owner AND group to root -weight: 600;">sudo chown daniyal file.txt # Change owner only -weight: 600;">sudo chown daniyal:www-data file.txt # Change owner to daniyal, group to www-data -weight: 600;">sudo chown -R www-data:www-data /var/www/html/ # Recursive (all files inside) cat /etc/passwd # List ALL users on the system -weight: 600;">sudo adduser newuser # Create new user (interactive - sets password) -weight: 600;">sudo useradd newuser # Create user (non-interactive - no password set) -weight: 600;">sudo usermod -aG -weight: 600;">sudo newuser # Add user to -weight: 600;">sudo group (give admin rights) -weight: 600;">sudo userdel newuser # Delete a user -weight: 600;">sudo userdel -r newuser # Delete user AND their home directory su - newuser # Switch to another user whoami # Show current username id # Show user ID, group ID, and groups cat /etc/passwd # List ALL users on the system -weight: 600;">sudo adduser newuser # Create new user (interactive - sets password) -weight: 600;">sudo useradd newuser # Create user (non-interactive - no password set) -weight: 600;">sudo usermod -aG -weight: 600;">sudo newuser # Add user to -weight: 600;">sudo group (give admin rights) -weight: 600;">sudo userdel newuser # Delete a user -weight: 600;">sudo userdel -r newuser # Delete user AND their home directory su - newuser # Switch to another user whoami # Show current username id # Show user ID, group ID, and groups cat /etc/passwd # List ALL users on the system -weight: 600;">sudo adduser newuser # Create new user (interactive - sets password) -weight: 600;">sudo useradd newuser # Create user (non-interactive - no password set) -weight: 600;">sudo usermod -aG -weight: 600;">sudo newuser # Add user to -weight: 600;">sudo group (give admin rights) -weight: 600;">sudo userdel newuser # Delete a user -weight: 600;">sudo userdel -r newuser # Delete user AND their home directory su - newuser # Switch to another user whoami # Show current username id # Show user ID, group ID, and groups cat /etc/group # List all groups -weight: 600;">sudo groupadd devopsgroup # Create a new group -weight: 600;">sudo usermod -aG devopsgroup user1 # Add user1 to devopsgroup -weight: 600;">sudo groupdel devopsgroup # Delete a group groups username # Show which groups a user belongs to cat /etc/group # List all groups -weight: 600;">sudo groupadd devopsgroup # Create a new group -weight: 600;">sudo usermod -aG devopsgroup user1 # Add user1 to devopsgroup -weight: 600;">sudo groupdel devopsgroup # Delete a group groups username # Show which groups a user belongs to cat /etc/group # List all groups -weight: 600;">sudo groupadd devopsgroup # Create a new group -weight: 600;">sudo usermod -aG devopsgroup user1 # Add user1 to devopsgroup -weight: 600;">sudo groupdel devopsgroup # Delete a group groups username # Show which groups a user belongs to ssh username@remote_server_ip # Connect to remote machine ssh [email protected] # Example with IP whoami # Verify you are logged in hostname # Verify which machine you are on exit # Disconnect from remote ssh username@remote_server_ip # Connect to remote machine ssh [email protected] # Example with IP whoami # Verify you are logged in hostname # Verify which machine you are on exit # Disconnect from remote ssh username@remote_server_ip # Connect to remote machine ssh [email protected] # Example with IP whoami # Verify you are logged in hostname # Verify which machine you are on exit # Disconnect from remote -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status ssh # Check if SSH is running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start ssh # Start SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop ssh # Stop SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Restart (apply config changes) -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable ssh # Start automatically on boot -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">disable ssh # Don't -weight: 500;">start on boot -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status ssh # Check if SSH is running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start ssh # Start SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop ssh # Stop SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Restart (apply config changes) -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable ssh # Start automatically on boot -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">disable ssh # Don't -weight: 500;">start on boot -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status ssh # Check if SSH is running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start ssh # Start SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop ssh # Stop SSH -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Restart (apply config changes) -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable ssh # Start automatically on boot -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">disable ssh # Don't -weight: 500;">start on boot -weight: 600;">sudo nano /etc/ssh/sshd_config # Edit SSH server configuration # Key settings to know: Port 22 # Default SSH port PermitRootLogin yes/no # Allow/block root login via SSH PasswordAuthentication yes/no # Allow/block password-based login PubkeyAuthentication yes # Allow key-based authentication # IMPORTANT: After ANY change, -weight: 500;">restart SSH! -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh -weight: 600;">sudo nano /etc/ssh/sshd_config # Edit SSH server configuration # Key settings to know: Port 22 # Default SSH port PermitRootLogin yes/no # Allow/block root login via SSH PasswordAuthentication yes/no # Allow/block password-based login PubkeyAuthentication yes # Allow key-based authentication # IMPORTANT: After ANY change, -weight: 500;">restart SSH! -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh -weight: 600;">sudo nano /etc/ssh/sshd_config # Edit SSH server configuration # Key settings to know: Port 22 # Default SSH port PermitRootLogin yes/no # Allow/block root login via SSH PasswordAuthentication yes/no # Allow/block password-based login PubkeyAuthentication yes # Allow key-based authentication # IMPORTANT: After ANY change, -weight: 500;">restart SSH! -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # STEP 1: Generate key pair on YOUR machine (client) ssh-keygen -t rsa # Press Enter for default location (~/.ssh/id_rsa) # Press Enter for no passphrase (or set one for extra security) # Creates: ~/.ssh/id_rsa (private) and ~/.ssh/id_rsa.pub (public) # STEP 2: Copy public key to the REMOTE server ssh-copy-id username@remote_server # OR manually: cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys # On the remote server # STEP 3: Set correct permissions (CRITICAL!) chmod 700 ~/.ssh # Directory: owner only chmod 600 ~/.ssh/id_rsa # Private key: owner only chmod 600 ~/.ssh/authorized_keys # Auth keys: owner only # STEP 4: Now you can login without password! ssh username@remote_server # STEP 1: Generate key pair on YOUR machine (client) ssh-keygen -t rsa # Press Enter for default location (~/.ssh/id_rsa) # Press Enter for no passphrase (or set one for extra security) # Creates: ~/.ssh/id_rsa (private) and ~/.ssh/id_rsa.pub (public) # STEP 2: Copy public key to the REMOTE server ssh-copy-id username@remote_server # OR manually: cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys # On the remote server # STEP 3: Set correct permissions (CRITICAL!) chmod 700 ~/.ssh # Directory: owner only chmod 600 ~/.ssh/id_rsa # Private key: owner only chmod 600 ~/.ssh/authorized_keys # Auth keys: owner only # STEP 4: Now you can login without password! ssh username@remote_server # STEP 1: Generate key pair on YOUR machine (client) ssh-keygen -t rsa # Press Enter for default location (~/.ssh/id_rsa) # Press Enter for no passphrase (or set one for extra security) # Creates: ~/.ssh/id_rsa (private) and ~/.ssh/id_rsa.pub (public) # STEP 2: Copy public key to the REMOTE server ssh-copy-id username@remote_server # OR manually: cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys # On the remote server # STEP 3: Set correct permissions (CRITICAL!) chmod 700 ~/.ssh # Directory: owner only chmod 600 ~/.ssh/id_rsa # Private key: owner only chmod 600 ~/.ssh/authorized_keys # Auth keys: owner only # STEP 4: Now you can login without password! ssh username@remote_server # File: ~/.ssh/config Host myserver HostName 192.168.1.100 User daniyal IdentityFile ~/.ssh/id_rsa # Now you can just type: ssh myserver # Instead of: ssh [email protected] # File: ~/.ssh/config Host myserver HostName 192.168.1.100 User daniyal IdentityFile ~/.ssh/id_rsa # Now you can just type: ssh myserver # Instead of: ssh [email protected] # File: ~/.ssh/config Host myserver HostName 192.168.1.100 User daniyal IdentityFile ~/.ssh/id_rsa # Now you can just type: ssh myserver # Instead of: ssh [email protected] ssh user@server "whoami" # Run whoami on remote ssh user@server "mkdir ~/test_dir" # Create dir on remote ssh user@server "cat /etc/hostname" # Read remote file ssh user@server "-weight: 500;">systemctl -weight: 500;">restart apache2" # Restart -weight: 500;">service remotely ssh user@server "whoami" # Run whoami on remote ssh user@server "mkdir ~/test_dir" # Create dir on remote ssh user@server "cat /etc/hostname" # Read remote file ssh user@server "-weight: 500;">systemctl -weight: 500;">restart apache2" # Restart -weight: 500;">service remotely ssh user@server "whoami" # Run whoami on remote ssh user@server "mkdir ~/test_dir" # Create dir on remote ssh user@server "cat /etc/hostname" # Read remote file ssh user@server "-weight: 500;">systemctl -weight: 500;">restart apache2" # Restart -weight: 500;">service remotely # Edit /etc/ssh/sshd_config: PermitRootLogin no # Block root from logging in via SSH PasswordAuthentication no # Force key-based auth only # Restart to apply: -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Test: trying ssh root@server should now be DENIED # Edit /etc/ssh/sshd_config: PermitRootLogin no # Block root from logging in via SSH PasswordAuthentication no # Force key-based auth only # Restart to apply: -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Test: trying ssh root@server should now be DENIED # Edit /etc/ssh/sshd_config: PermitRootLogin no # Block root from logging in via SSH PasswordAuthentication no # Force key-based auth only # Restart to apply: -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart ssh # Test: trying ssh root@server should now be DENIED -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install apache2 # Install Apache -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Start the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop apache2 # Stop the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart apache2 # Restart (apply changes) -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Reload config without downtime -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 # Check if running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable apache2 # Start on boot -weight: 500;">curl localhost # Test: should show Apache default page -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install apache2 # Install Apache -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Start the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop apache2 # Stop the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart apache2 # Restart (apply changes) -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Reload config without downtime -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 # Check if running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable apache2 # Start on boot -weight: 500;">curl localhost # Test: should show Apache default page -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install apache2 # Install Apache -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Start the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop apache2 # Stop the -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart apache2 # Restart (apply changes) -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Reload config without downtime -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 # Check if running -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable apache2 # Start on boot -weight: 500;">curl localhost # Test: should show Apache default page # Step 1: Clone or copy your website files -weight: 600;">sudo -weight: 500;">git clone https://github.com/user/repo.-weight: 500;">git /var/www/html/mysite # Step 2: Set correct ownership -weight: 600;">sudo chown -R www-data:www-data /var/www/html/mysite # Step 3: Set correct permissions -weight: 600;">sudo chmod -R 755 /var/www/html/mysite/ # Directories -weight: 600;">sudo find /var/www/html/mysite -type f -exec chmod 644 {} \; # Files # Step 4: Verify -weight: 500;">curl localhost # Step 1: Clone or copy your website files -weight: 600;">sudo -weight: 500;">git clone https://github.com/user/repo.-weight: 500;">git /var/www/html/mysite # Step 2: Set correct ownership -weight: 600;">sudo chown -R www-data:www-data /var/www/html/mysite # Step 3: Set correct permissions -weight: 600;">sudo chmod -R 755 /var/www/html/mysite/ # Directories -weight: 600;">sudo find /var/www/html/mysite -type f -exec chmod 644 {} \; # Files # Step 4: Verify -weight: 500;">curl localhost # Step 1: Clone or copy your website files -weight: 600;">sudo -weight: 500;">git clone https://github.com/user/repo.-weight: 500;">git /var/www/html/mysite # Step 2: Set correct ownership -weight: 600;">sudo chown -R www-data:www-data /var/www/html/mysite # Step 3: Set correct permissions -weight: 600;">sudo chmod -R 755 /var/www/html/mysite/ # Directories -weight: 600;">sudo find /var/www/html/mysite -type f -exec chmod 644 {} \; # Files # Step 4: Verify -weight: 500;">curl localhost # Step 1: Create config file in sites-available -weight: 600;">sudo nano /etc/apache2/sites-available/mysite.conf # Step 1: Create config file in sites-available -weight: 600;">sudo nano /etc/apache2/sites-available/mysite.conf # Step 1: Create config file in sites-available -weight: 600;">sudo nano /etc/apache2/sites-available/mysite.conf <VirtualHost *:8080> ServerName mysite.local DocumentRoot /var/www/mysite ErrorLog /var/log/apache2/mysite-error.log CustomLog /var/log/apache2/mysite-access.log combined </VirtualHost> <VirtualHost *:8080> ServerName mysite.local DocumentRoot /var/www/mysite ErrorLog /var/log/apache2/mysite-error.log CustomLog /var/log/apache2/mysite-access.log combined </VirtualHost> <VirtualHost *:8080> ServerName mysite.local DocumentRoot /var/www/mysite ErrorLog /var/log/apache2/mysite-error.log CustomLog /var/log/apache2/mysite-access.log combined </VirtualHost> # Step 2: Add Listen directive for new port # Edit /etc/apache2/ports.conf and add: Listen 8080 # Step 3: Enable the site -weight: 600;">sudo a2ensite mysite.conf # Step 4: Test config and reload -weight: 600;">sudo apache2ctl configtest # Check for syntax errors -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Step 5: Verify -weight: 500;">curl localhost:8080 # Step 2: Add Listen directive for new port # Edit /etc/apache2/ports.conf and add: Listen 8080 # Step 3: Enable the site -weight: 600;">sudo a2ensite mysite.conf # Step 4: Test config and reload -weight: 600;">sudo apache2ctl configtest # Check for syntax errors -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Step 5: Verify -weight: 500;">curl localhost:8080 # Step 2: Add Listen directive for new port # Edit /etc/apache2/ports.conf and add: Listen 8080 # Step 3: Enable the site -weight: 600;">sudo a2ensite mysite.conf # Step 4: Test config and reload -weight: 600;">sudo apache2ctl configtest # Check for syntax errors -weight: 600;">sudo -weight: 500;">systemctl reload apache2 # Step 5: Verify -weight: 500;">curl localhost:8080 -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable nginx -weight: 500;">curl localhost # Test -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable nginx -weight: 500;">curl localhost # Test -weight: 600;">sudo -weight: 500;">apt -weight: 500;">update -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">restart nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status nginx -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">enable nginx -weight: 500;">curl localhost # Test # File: /etc/nginx/sites-available/mysite server { listen 80; server_name mysite.local; root /var/www/mysite; index index.html; location / { try_files $uri $uri/ =404; } } # File: /etc/nginx/sites-available/mysite server { listen 80; server_name mysite.local; root /var/www/mysite; index index.html; location / { try_files $uri $uri/ =404; } } # File: /etc/nginx/sites-available/mysite server { listen 80; server_name mysite.local; root /var/www/mysite; index index.html; location / { try_files $uri $uri/ =404; } } # Enable the site by creating a symlink: -weight: 600;">sudo ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/ # Test config: -weight: 600;">sudo nginx -t # Reload: -weight: 600;">sudo -weight: 500;">systemctl reload nginx # Enable the site by creating a symlink: -weight: 600;">sudo ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/ # Test config: -weight: 600;">sudo nginx -t # Reload: -weight: 600;">sudo -weight: 500;">systemctl reload nginx # Enable the site by creating a symlink: -weight: 600;">sudo ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/ # Test config: -weight: 600;">sudo nginx -t # Reload: -weight: 600;">sudo -weight: 500;">systemctl reload nginx # Check what's using a specific port -weight: 600;">sudo lsof -i :80 # Show process using port 80 # Production-friendly command (all open network connections) -weight: 600;">sudo lsof -i -P -n # -i = open network connections # -P = show port numbers (not -weight: 500;">service names) # -n = don't resolve hostnames # Check -weight: 500;">service logs for errors -weight: 600;">sudo journalctl -xe # Show recent system logs with details -weight: 600;">sudo journalctl -u apache2 # Show only Apache logs # Monitor log files in real-time -weight: 600;">sudo tail -f /var/log/apache2/error.log -weight: 600;">sudo tail -f /var/log/nginx/error.log # Check what's using a specific port -weight: 600;">sudo lsof -i :80 # Show process using port 80 # Production-friendly command (all open network connections) -weight: 600;">sudo lsof -i -P -n # -i = open network connections # -P = show port numbers (not -weight: 500;">service names) # -n = don't resolve hostnames # Check -weight: 500;">service logs for errors -weight: 600;">sudo journalctl -xe # Show recent system logs with details -weight: 600;">sudo journalctl -u apache2 # Show only Apache logs # Monitor log files in real-time -weight: 600;">sudo tail -f /var/log/apache2/error.log -weight: 600;">sudo tail -f /var/log/nginx/error.log # Check what's using a specific port -weight: 600;">sudo lsof -i :80 # Show process using port 80 # Production-friendly command (all open network connections) -weight: 600;">sudo lsof -i -P -n # -i = open network connections # -P = show port numbers (not -weight: 500;">service names) # -n = don't resolve hostnames # Check -weight: 500;">service logs for errors -weight: 600;">sudo journalctl -xe # Show recent system logs with details -weight: 600;">sudo journalctl -u apache2 # Show only Apache logs # Monitor log files in real-time -weight: 600;">sudo tail -f /var/log/apache2/error.log -weight: 600;">sudo tail -f /var/log/nginx/error.log # Step 1: Check which -weight: 500;">service is using port 80 -weight: 600;">sudo lsof -i :80 # Output shows: nginx (PID 1234) # Step 2: Stop the conflicting -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx # Step 3: Start the -weight: 500;">service you want -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Step 4: Verify -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 -weight: 500;">curl localhost # Step 1: Check which -weight: 500;">service is using port 80 -weight: 600;">sudo lsof -i :80 # Output shows: nginx (PID 1234) # Step 2: Stop the conflicting -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx # Step 3: Start the -weight: 500;">service you want -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Step 4: Verify -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 -weight: 500;">curl localhost # Step 1: Check which -weight: 500;">service is using port 80 -weight: 600;">sudo lsof -i :80 # Output shows: nginx (PID 1234) # Step 2: Stop the conflicting -weight: 500;">service -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">stop nginx # Step 3: Start the -weight: 500;">service you want -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">start apache2 # Step 4: Verify -weight: 600;">sudo -weight: 500;">systemctl -weight: 500;">status apache2 -weight: 500;">curl localhost #!/bin/bash # The first line is the SHEBANG — tells the system to use bash # Every script MUST -weight: 500;">start with #!/bin/bash # Make script executable: chmod +x script.sh # Run script: ./script.sh # OR bash script.sh #!/bin/bash # The first line is the SHEBANG — tells the system to use bash # Every script MUST -weight: 500;">start with #!/bin/bash # Make script executable: chmod +x script.sh # Run script: ./script.sh # OR bash script.sh #!/bin/bash # The first line is the SHEBANG — tells the system to use bash # Every script MUST -weight: 500;">start with #!/bin/bash # Make script executable: chmod +x script.sh # Run script: ./script.sh # OR bash script.sh #!/bin/bash NAME="Daniyal" # Assign (NO spaces around =) echo "Hello $NAME" # Use variable with $ echo "Hello ${NAME}" # Curly braces version (safer) # Read user input echo "Enter your name:" read USERNAME # Stores input in USERNAME echo "Welcome $USERNAME" # Command substitution — store command output in variable TODAY=$(date) # Run date command, store result echo "Today is: $TODAY" HOSTNAME=$(hostname) echo "Machine: $HOSTNAME" #!/bin/bash NAME="Daniyal" # Assign (NO spaces around =) echo "Hello $NAME" # Use variable with $ echo "Hello ${NAME}" # Curly braces version (safer) # Read user input echo "Enter your name:" read USERNAME # Stores input in USERNAME echo "Welcome $USERNAME" # Command substitution — store command output in variable TODAY=$(date) # Run date command, store result echo "Today is: $TODAY" HOSTNAME=$(hostname) echo "Machine: $HOSTNAME" #!/bin/bash NAME="Daniyal" # Assign (NO spaces around =) echo "Hello $NAME" # Use variable with $ echo "Hello ${NAME}" # Curly braces version (safer) # Read user input echo "Enter your name:" read USERNAME # Stores input in USERNAME echo "Welcome $USERNAME" # Command substitution — store command output in variable TODAY=$(date) # Run date command, store result echo "Today is: $TODAY" HOSTNAME=$(hostname) echo "Machine: $HOSTNAME" #!/bin/bash # Example: ./myscript.sh hello world echo "Script name: $0" # ./myscript.sh echo "First arg: $1" # hello echo "Second arg: $2" # world echo "Total args: $#" # 2 echo "All args: $@" # hello world #!/bin/bash # Example: ./myscript.sh hello world echo "Script name: $0" # ./myscript.sh echo "First arg: $1" # hello echo "Second arg: $2" # world echo "Total args: $#" # 2 echo "All args: $@" # hello world #!/bin/bash # Example: ./myscript.sh hello world echo "Script name: $0" # ./myscript.sh echo "First arg: $1" # hello echo "Second arg: $2" # world echo "Total args: $#" # 2 echo "All args: $@" # hello world #!/bin/bash # Every command returns an exit code # 0 = SUCCESS, anything else = FAILURE ls /tmp echo $? # 0 (success — /tmp exists) ls /nonexistent echo $? # 2 (failure — directory doesn't exist) # Set your own exit code exit 0 # Exit script with success exit 1 # Exit script with failure #!/bin/bash # Every command returns an exit code # 0 = SUCCESS, anything else = FAILURE ls /tmp echo $? # 0 (success — /tmp exists) ls /nonexistent echo $? # 2 (failure — directory doesn't exist) # Set your own exit code exit 0 # Exit script with success exit 1 # Exit script with failure #!/bin/bash # Every command returns an exit code # 0 = SUCCESS, anything else = FAILURE ls /tmp echo $? # 0 (success — /tmp exists) ls /nonexistent echo $? # 2 (failure — directory doesn't exist) # Set your own exit code exit 0 # Exit script with success exit 1 # Exit script with failure #!/bin/bash # Basic if/else if [ -d "/var/www/html" ]; then echo "Directory exists" else echo "Directory does NOT exist" fi # Check if file exists if [ -f "/etc/ssh/sshd_config" ]; then echo "SSH config found" fi # Compare strings if [ "$1" == "-weight: 500;">install" ]; then echo "Installing..." elif [ "$1" == "-weight: 500;">remove" ]; then echo "Removing..." else echo "Usage: $0 -weight: 500;">install|-weight: 500;">remove" exit 1 fi # Check if command succeeded -weight: 500;">apt -weight: 500;">install nginx -y if [ $? -eq 0 ]; then echo "Installation successful" else echo "Installation FAILED" exit 1 fi #!/bin/bash # Basic if/else if [ -d "/var/www/html" ]; then echo "Directory exists" else echo "Directory does NOT exist" fi # Check if file exists if [ -f "/etc/ssh/sshd_config" ]; then echo "SSH config found" fi # Compare strings if [ "$1" == "-weight: 500;">install" ]; then echo "Installing..." elif [ "$1" == "-weight: 500;">remove" ]; then echo "Removing..." else echo "Usage: $0 -weight: 500;">install|-weight: 500;">remove" exit 1 fi # Check if command succeeded -weight: 500;">apt -weight: 500;">install nginx -y if [ $? -eq 0 ]; then echo "Installation successful" else echo "Installation FAILED" exit 1 fi #!/bin/bash # Basic if/else if [ -d "/var/www/html" ]; then echo "Directory exists" else echo "Directory does NOT exist" fi # Check if file exists if [ -f "/etc/ssh/sshd_config" ]; then echo "SSH config found" fi # Compare strings if [ "$1" == "-weight: 500;">install" ]; then echo "Installing..." elif [ "$1" == "-weight: 500;">remove" ]; then echo "Removing..." else echo "Usage: $0 -weight: 500;">install|-weight: 500;">remove" exit 1 fi # Check if command succeeded -weight: 500;">apt -weight: 500;">install nginx -y if [ $? -eq 0 ]; then echo "Installation successful" else echo "Installation FAILED" exit 1 fi #!/bin/bash # Great for handling command-line flags like -i, -r, -h case "$1" in -i|---weight: 500;">install) echo "Installing..." ;; -r|---weight: 500;">remove) echo "Removing..." ;; -h|--help) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove] [-h help]" ;; *) echo "Invalid option: $1" echo "Use -h for help" exit 1 ;; esac #!/bin/bash # Great for handling command-line flags like -i, -r, -h case "$1" in -i|---weight: 500;">install) echo "Installing..." ;; -r|---weight: 500;">remove) echo "Removing..." ;; -h|--help) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove] [-h help]" ;; *) echo "Invalid option: $1" echo "Use -h for help" exit 1 ;; esac #!/bin/bash # Great for handling command-line flags like -i, -r, -h case "$1" in -i|---weight: 500;">install) echo "Installing..." ;; -r|---weight: 500;">remove) echo "Removing..." ;; -h|--help) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove] [-h help]" ;; *) echo "Invalid option: $1" echo "Use -h for help" exit 1 ;; esac #!/bin/bash # Loop through a list for server in server1 server2 server3; do echo "Restarting $server..." ssh $server "-weight: 500;">systemctl -weight: 500;">restart apache2" done # Loop through files for file in *.sh; do echo "Found script: $file" done # Loop with numbers for i in 1 2 3 4 5; do echo "Number: $i" done # C-style loop for ((i=1; i<=5; i++)); do echo "Count: $i" done #!/bin/bash # Loop through a list for server in server1 server2 server3; do echo "Restarting $server..." ssh $server "-weight: 500;">systemctl -weight: 500;">restart apache2" done # Loop through files for file in *.sh; do echo "Found script: $file" done # Loop with numbers for i in 1 2 3 4 5; do echo "Number: $i" done # C-style loop for ((i=1; i<=5; i++)); do echo "Count: $i" done #!/bin/bash # Loop through a list for server in server1 server2 server3; do echo "Restarting $server..." ssh $server "-weight: 500;">systemctl -weight: 500;">restart apache2" done # Loop through files for file in *.sh; do echo "Found script: $file" done # Loop with numbers for i in 1 2 3 4 5; do echo "Number: $i" done # C-style loop for ((i=1; i<=5; i++)); do echo "Count: $i" done # Create a compressed archive tar -czf backup.tar.gz /path/to/directory # -c = create # -z = compress with gzip # -f = filename follows # Create with timestamp in name tar -czf backup_$(date +%Y%m%d_%H%M%S).tar.gz /var/www/html/ # Extract an archive tar -xzf backup.tar.gz # -x = extract # List contents without extracting tar -tzf backup.tar.gz # Create a compressed archive tar -czf backup.tar.gz /path/to/directory # -c = create # -z = compress with gzip # -f = filename follows # Create with timestamp in name tar -czf backup_$(date +%Y%m%d_%H%M%S).tar.gz /var/www/html/ # Extract an archive tar -xzf backup.tar.gz # -x = extract # List contents without extracting tar -tzf backup.tar.gz # Create a compressed archive tar -czf backup.tar.gz /path/to/directory # -c = create # -z = compress with gzip # -f = filename follows # Create with timestamp in name tar -czf backup_$(date +%Y%m%d_%H%M%S).tar.gz /var/www/html/ # Extract an archive tar -xzf backup.tar.gz # -x = extract # List contents without extracting tar -tzf backup.tar.gz # awk processes text line by line, splitting into fields # Default field separator is whitespace # Print second column of output df -h | awk '{print $2}' # Print specific fields with custom format free -m | awk '/Mem:/ {print "Total: "$2" MB, Used: "$3" MB"}' # Use custom field separator cat /etc/passwd | awk -F: '{print $1}' # Print usernames (field 1, : separator) # Filter lines matching a pattern df -h | awk '!/tmpfs/ {print $0}' # Exclude lines containing tmpfs # awk processes text line by line, splitting into fields # Default field separator is whitespace # Print second column of output df -h | awk '{print $2}' # Print specific fields with custom format free -m | awk '/Mem:/ {print "Total: "$2" MB, Used: "$3" MB"}' # Use custom field separator cat /etc/passwd | awk -F: '{print $1}' # Print usernames (field 1, : separator) # Filter lines matching a pattern df -h | awk '!/tmpfs/ {print $0}' # Exclude lines containing tmpfs # awk processes text line by line, splitting into fields # Default field separator is whitespace # Print second column of output df -h | awk '{print $2}' # Print specific fields with custom format free -m | awk '/Mem:/ {print "Total: "$2" MB, Used: "$3" MB"}' # Use custom field separator cat /etc/passwd | awk -F: '{print $1}' # Print usernames (field 1, : separator) # Filter lines matching a pattern df -h | awk '!/tmpfs/ {print $0}' # Exclude lines containing tmpfs #!/bin/bash # Heredoc writes multi-line content to a file cat << EOF > /var/www/html/index.html <!DOCTYPE html> <html> <head><title>System Report</title></head> <body> <h1>Server: $(hostname)</h1> <p>Date: $(date)</p> </body> </html> EOF # Variables inside heredoc get expanded! # Use << 'EOF' (with quotes) to PREVENT variable expansion #!/bin/bash # Heredoc writes multi-line content to a file cat << EOF > /var/www/html/index.html <!DOCTYPE html> <html> <head><title>System Report</title></head> <body> <h1>Server: $(hostname)</h1> <p>Date: $(date)</p> </body> </html> EOF # Variables inside heredoc get expanded! # Use << 'EOF' (with quotes) to PREVENT variable expansion #!/bin/bash # Heredoc writes multi-line content to a file cat << EOF > /var/www/html/index.html <!DOCTYPE html> <html> <head><title>System Report</title></head> <body> <h1>Server: $(hostname)</h1> <p>Date: $(date)</p> </body> </html> EOF # Variables inside heredoc get expanded! # Use << 'EOF' (with quotes) to PREVENT variable expansion #!/bin/bash # Redirect command output to log file -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 # > nginx.log = redirect stdout to file # 2>&1 = redirect stderr (2) to same place as stdout (1) # Combined: ALL output (normal + errors) goes to nginx.log # Append to log echo "$(date) - Installation complete" >> nginx.log #!/bin/bash # Redirect command output to log file -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 # > nginx.log = redirect stdout to file # 2>&1 = redirect stderr (2) to same place as stdout (1) # Combined: ALL output (normal + errors) goes to nginx.log # Append to log echo "$(date) - Installation complete" >> nginx.log #!/bin/bash # Redirect command output to log file -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 # > nginx.log = redirect stdout to file # 2>&1 = redirect stderr (2) to same place as stdout (1) # Combined: ALL output (normal + errors) goes to nginx.log # Append to log echo "$(date) - Installation complete" >> nginx.log #!/bin/bash echo "Enter directory path to backup:" read DIR_PATH if [ ! -d "$DIR_PATH" ]; then echo "ERROR: Directory $DIR_PATH does not exist!" exit 1 fi TIMESTAMP=$(date +%Y%m%d_%H%M%S) BACKUP_FILE="backup_${TIMESTAMP}.tar.gz" tar -czf "$BACKUP_FILE" "$DIR_PATH" if [ $? -eq 0 ]; then echo "SUCCESS: Backup created: $BACKUP_FILE" echo "$(date) - SUCCESS - $BACKUP_FILE" >> backup.log else echo "FAILED: Backup failed!" echo "$(date) - FAILED" >> backup.log exit 1 fi #!/bin/bash echo "Enter directory path to backup:" read DIR_PATH if [ ! -d "$DIR_PATH" ]; then echo "ERROR: Directory $DIR_PATH does not exist!" exit 1 fi TIMESTAMP=$(date +%Y%m%d_%H%M%S) BACKUP_FILE="backup_${TIMESTAMP}.tar.gz" tar -czf "$BACKUP_FILE" "$DIR_PATH" if [ $? -eq 0 ]; then echo "SUCCESS: Backup created: $BACKUP_FILE" echo "$(date) - SUCCESS - $BACKUP_FILE" >> backup.log else echo "FAILED: Backup failed!" echo "$(date) - FAILED" >> backup.log exit 1 fi #!/bin/bash echo "Enter directory path to backup:" read DIR_PATH if [ ! -d "$DIR_PATH" ]; then echo "ERROR: Directory $DIR_PATH does not exist!" exit 1 fi TIMESTAMP=$(date +%Y%m%d_%H%M%S) BACKUP_FILE="backup_${TIMESTAMP}.tar.gz" tar -czf "$BACKUP_FILE" "$DIR_PATH" if [ $? -eq 0 ]; then echo "SUCCESS: Backup created: $BACKUP_FILE" echo "$(date) - SUCCESS - $BACKUP_FILE" >> backup.log else echo "FAILED: Backup failed!" echo "$(date) - FAILED" >> backup.log exit 1 fi #!/bin/bash echo "Enter domain/directory name:" read DOMAIN -weight: 600;">sudo mkdir -p /var/www/$DOMAIN -weight: 600;">sudo cat << EOF > /var/www/$DOMAIN/index.html <html><body><h1>Welcome to $DOMAIN</h1></body></html> EOF -weight: 600;">sudo cat << EOF > /etc/apache2/sites-available/$DOMAIN.conf <VirtualHost *:80> ServerName $DOMAIN DocumentRoot /var/www/$DOMAIN ErrorLog /var/log/apache2/${DOMAIN}-error.log CustomLog /var/log/apache2/${DOMAIN}-access.log combined </VirtualHost> EOF -weight: 600;">sudo chown -R www-data:www-data /var/www/$DOMAIN -weight: 600;">sudo chmod -R 755 /var/www/$DOMAIN -weight: 600;">sudo a2ensite $DOMAIN.conf -weight: 600;">sudo -weight: 500;">systemctl reload apache2 echo "Website $DOMAIN deployed successfully!" #!/bin/bash echo "Enter domain/directory name:" read DOMAIN -weight: 600;">sudo mkdir -p /var/www/$DOMAIN -weight: 600;">sudo cat << EOF > /var/www/$DOMAIN/index.html <html><body><h1>Welcome to $DOMAIN</h1></body></html> EOF -weight: 600;">sudo cat << EOF > /etc/apache2/sites-available/$DOMAIN.conf <VirtualHost *:80> ServerName $DOMAIN DocumentRoot /var/www/$DOMAIN ErrorLog /var/log/apache2/${DOMAIN}-error.log CustomLog /var/log/apache2/${DOMAIN}-access.log combined </VirtualHost> EOF -weight: 600;">sudo chown -R www-data:www-data /var/www/$DOMAIN -weight: 600;">sudo chmod -R 755 /var/www/$DOMAIN -weight: 600;">sudo a2ensite $DOMAIN.conf -weight: 600;">sudo -weight: 500;">systemctl reload apache2 echo "Website $DOMAIN deployed successfully!" #!/bin/bash echo "Enter domain/directory name:" read DOMAIN -weight: 600;">sudo mkdir -p /var/www/$DOMAIN -weight: 600;">sudo cat << EOF > /var/www/$DOMAIN/index.html <html><body><h1>Welcome to $DOMAIN</h1></body></html> EOF -weight: 600;">sudo cat << EOF > /etc/apache2/sites-available/$DOMAIN.conf <VirtualHost *:80> ServerName $DOMAIN DocumentRoot /var/www/$DOMAIN ErrorLog /var/log/apache2/${DOMAIN}-error.log CustomLog /var/log/apache2/${DOMAIN}-access.log combined </VirtualHost> EOF -weight: 600;">sudo chown -R www-data:www-data /var/www/$DOMAIN -weight: 600;">sudo chmod -R 755 /var/www/$DOMAIN -weight: 600;">sudo a2ensite $DOMAIN.conf -weight: 600;">sudo -weight: 500;">systemctl reload apache2 echo "Website $DOMAIN deployed successfully!" #!/bin/bash case "$1" in -i) if dpkg -l | grep -q nginx; then echo "Nginx is already installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx installed successfully." else echo "ERROR: Installation failed. Check nginx.log" exit 1 fi ;; -r) if ! dpkg -l | grep -q nginx; then echo "Nginx is not installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">remove nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx removed successfully." else echo "ERROR: Removal failed. Check nginx.log" exit 1 fi ;; *) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove]" exit 1 ;; esac #!/bin/bash case "$1" in -i) if dpkg -l | grep -q nginx; then echo "Nginx is already installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx installed successfully." else echo "ERROR: Installation failed. Check nginx.log" exit 1 fi ;; -r) if ! dpkg -l | grep -q nginx; then echo "Nginx is not installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">remove nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx removed successfully." else echo "ERROR: Removal failed. Check nginx.log" exit 1 fi ;; *) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove]" exit 1 ;; esac #!/bin/bash case "$1" in -i) if dpkg -l | grep -q nginx; then echo "Nginx is already installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">install nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx installed successfully." else echo "ERROR: Installation failed. Check nginx.log" exit 1 fi ;; -r) if ! dpkg -l | grep -q nginx; then echo "Nginx is not installed." exit 0 fi -weight: 600;">sudo -weight: 500;">apt -weight: 500;">remove nginx -y > nginx.log 2>&1 if [ $? -eq 0 ]; then echo "Nginx removed successfully." else echo "ERROR: Removal failed. Check nginx.log" exit 1 fi ;; *) echo "Usage: $0 [-i -weight: 500;">install] [-r -weight: 500;">remove]" exit 1 ;; esac #!/bin/bash TOTAL_MEM=$(free -m | awk '/Mem:/ {print $2}') USED_MEM=$(free -m | awk '/Mem:/ {print $3}') AVAIL_MEM=$(free -m | awk '/Mem:/ {print $7}') TOTAL_SWAP=$(free -m | awk '/Swap:/ {print $2}') USED_SWAP=$(free -m | awk '/Swap:/ {print $3}') DISK_TOTAL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $2}') DISK_USED=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $3}') DISK_AVAIL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $4}') cat << EOF > system_health.html <!DOCTYPE html> <html> <head><title>System Health Report</title></head> <body> <h1>System Health Report</h1> <p>Date: $(date)</p> <h2>Memory Usage</h2> <p>Total: ${TOTAL_MEM}MB | Used: ${USED_MEM}MB | Available: ${AVAIL_MEM}MB</p> <h2>Disk Usage</h2> <p>Total: $DISK_TOTAL | Used: $DISK_USED | Available: $DISK_AVAIL</p> </body> </html> EOF -weight: 600;">sudo cp system_health.html /var/www/html/index.html if [ $? -eq 0 ]; then echo "SUCCESS: Report hosted at http://localhost" else echo "ERROR: Failed to deploy report" exit 1 fi #!/bin/bash TOTAL_MEM=$(free -m | awk '/Mem:/ {print $2}') USED_MEM=$(free -m | awk '/Mem:/ {print $3}') AVAIL_MEM=$(free -m | awk '/Mem:/ {print $7}') TOTAL_SWAP=$(free -m | awk '/Swap:/ {print $2}') USED_SWAP=$(free -m | awk '/Swap:/ {print $3}') DISK_TOTAL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $2}') DISK_USED=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $3}') DISK_AVAIL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $4}') cat << EOF > system_health.html <!DOCTYPE html> <html> <head><title>System Health Report</title></head> <body> <h1>System Health Report</h1> <p>Date: $(date)</p> <h2>Memory Usage</h2> <p>Total: ${TOTAL_MEM}MB | Used: ${USED_MEM}MB | Available: ${AVAIL_MEM}MB</p> <h2>Disk Usage</h2> <p>Total: $DISK_TOTAL | Used: $DISK_USED | Available: $DISK_AVAIL</p> </body> </html> EOF -weight: 600;">sudo cp system_health.html /var/www/html/index.html if [ $? -eq 0 ]; then echo "SUCCESS: Report hosted at http://localhost" else echo "ERROR: Failed to deploy report" exit 1 fi #!/bin/bash TOTAL_MEM=$(free -m | awk '/Mem:/ {print $2}') USED_MEM=$(free -m | awk '/Mem:/ {print $3}') AVAIL_MEM=$(free -m | awk '/Mem:/ {print $7}') TOTAL_SWAP=$(free -m | awk '/Swap:/ {print $2}') USED_SWAP=$(free -m | awk '/Swap:/ {print $3}') DISK_TOTAL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $2}') DISK_USED=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $3}') DISK_AVAIL=$(df -h --total --exclude-type=tmpfs | awk '/total/ {print $4}') cat << EOF > system_health.html <!DOCTYPE html> <html> <head><title>System Health Report</title></head> <body> <h1>System Health Report</h1> <p>Date: $(date)</p> <h2>Memory Usage</h2> <p>Total: ${TOTAL_MEM}MB | Used: ${USED_MEM}MB | Available: ${AVAIL_MEM}MB</p> <h2>Disk Usage</h2> <p>Total: $DISK_TOTAL | Used: $DISK_USED | Available: $DISK_AVAIL</p> </body> </html> EOF -weight: 600;">sudo cp system_health.html /var/www/html/index.html if [ $? -eq 0 ]; then echo "SUCCESS: Report hosted at http://localhost" else echo "ERROR: Failed to deploy report" exit 1 fi #!/bin/bash echo "Kernel Name: $(uname -s)" echo "Kernel Release: $(uname -r)" echo "Processor: $(uname -p)" echo "OS: $(cat /etc/os-release | grep PRETTY_NAME | cut -d= -f2)" EDITOR="nano" echo "Favorite Editor: $EDITOR" echo "Editor Location: $(which $EDITOR)" echo "Documentation: $(whereis $EDITOR)" #!/bin/bash echo "Kernel Name: $(uname -s)" echo "Kernel Release: $(uname -r)" echo "Processor: $(uname -p)" echo "OS: $(cat /etc/os-release | grep PRETTY_NAME | cut -d= -f2)" EDITOR="nano" echo "Favorite Editor: $EDITOR" echo "Editor Location: $(which $EDITOR)" echo "Documentation: $(whereis $EDITOR)" #!/bin/bash echo "Kernel Name: $(uname -s)" echo "Kernel Release: $(uname -r)" echo "Processor: $(uname -p)" echo "OS: $(cat /etc/os-release | grep PRETTY_NAME | cut -d= -f2)" EDITOR="nano" echo "Favorite Editor: $EDITOR" echo "Editor Location: $(which $EDITOR)" echo "Documentation: $(whereis $EDITOR)" -weight: 500;">docker --version # Check Docker version -weight: 500;">docker version # Detailed client + server version -weight: 500;">docker run hello-world # Test Docker works -weight: 500;">docker --version # Check Docker version -weight: 500;">docker version # Detailed client + server version -weight: 500;">docker run hello-world # Test Docker works -weight: 500;">docker --version # Check Docker version -weight: 500;">docker version # Detailed client + server version -weight: 500;">docker run hello-world # Test Docker works # PULL an image from Docker Hub -weight: 500;">docker pull ubuntu # Download ubuntu image (latest) -weight: 500;">docker pull ubuntu:22.04 # Download specific version -weight: 500;">docker pull nginx # Download nginx image # RUN a container from an image -weight: 500;">docker run ubuntu # Runs and exits immediately (no process) -weight: 500;">docker run ubuntu sleep 5 # Runs, sleeps 5 seconds, then exits # RUN in interactive mode (get a shell inside container) -weight: 500;">docker run -it ubuntu bash # -i=interactive, -t=terminal # You are now INSIDE the container! echo "Hello Docker" ls exit # Exit container (container stops) # RUN with a custom name -weight: 500;">docker run --name myubuntu ubuntu sleep 30 # RUN in detached mode (background) -weight: 500;">docker run -d ubuntu sleep 300 # -d = detached (runs in background) -weight: 500;">docker run -dit --name test ubuntu bash # Detached + interactive # PULL an image from Docker Hub -weight: 500;">docker pull ubuntu # Download ubuntu image (latest) -weight: 500;">docker pull ubuntu:22.04 # Download specific version -weight: 500;">docker pull nginx # Download nginx image # RUN a container from an image -weight: 500;">docker run ubuntu # Runs and exits immediately (no process) -weight: 500;">docker run ubuntu sleep 5 # Runs, sleeps 5 seconds, then exits # RUN in interactive mode (get a shell inside container) -weight: 500;">docker run -it ubuntu bash # -i=interactive, -t=terminal # You are now INSIDE the container! echo "Hello Docker" ls exit # Exit container (container stops) # RUN with a custom name -weight: 500;">docker run --name myubuntu ubuntu sleep 30 # RUN in detached mode (background) -weight: 500;">docker run -d ubuntu sleep 300 # -d = detached (runs in background) -weight: 500;">docker run -dit --name test ubuntu bash # Detached + interactive # PULL an image from Docker Hub -weight: 500;">docker pull ubuntu # Download ubuntu image (latest) -weight: 500;">docker pull ubuntu:22.04 # Download specific version -weight: 500;">docker pull nginx # Download nginx image # RUN a container from an image -weight: 500;">docker run ubuntu # Runs and exits immediately (no process) -weight: 500;">docker run ubuntu sleep 5 # Runs, sleeps 5 seconds, then exits # RUN in interactive mode (get a shell inside container) -weight: 500;">docker run -it ubuntu bash # -i=interactive, -t=terminal # You are now INSIDE the container! echo "Hello Docker" ls exit # Exit container (container stops) # RUN with a custom name -weight: 500;">docker run --name myubuntu ubuntu sleep 30 # RUN in detached mode (background) -weight: 500;">docker run -d ubuntu sleep 300 # -d = detached (runs in background) -weight: 500;">docker run -dit --name test ubuntu bash # Detached + interactive # LIST containers -weight: 500;">docker ps # Show RUNNING containers only -weight: 500;">docker ps -a # Show ALL containers (running + stopped) # STOP a container -weight: 500;">docker -weight: 500;">stop <container_id> # Graceful -weight: 500;">stop -weight: 500;">docker -weight: 500;">stop myubuntu # Stop by name # REMOVE a container -weight: 500;">docker rm <container_id> # Remove stopped container -weight: 500;">docker rm myubuntu # Remove by name # STOP ALL containers at once -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # -q = quiet (only IDs) # REMOVE ALL containers -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all (running + stopped) # LIST containers -weight: 500;">docker ps # Show RUNNING containers only -weight: 500;">docker ps -a # Show ALL containers (running + stopped) # STOP a container -weight: 500;">docker -weight: 500;">stop <container_id> # Graceful -weight: 500;">stop -weight: 500;">docker -weight: 500;">stop myubuntu # Stop by name # REMOVE a container -weight: 500;">docker rm <container_id> # Remove stopped container -weight: 500;">docker rm myubuntu # Remove by name # STOP ALL containers at once -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # -q = quiet (only IDs) # REMOVE ALL containers -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all (running + stopped) # LIST containers -weight: 500;">docker ps # Show RUNNING containers only -weight: 500;">docker ps -a # Show ALL containers (running + stopped) # STOP a container -weight: 500;">docker -weight: 500;">stop <container_id> # Graceful -weight: 500;">stop -weight: 500;">docker -weight: 500;">stop myubuntu # Stop by name # REMOVE a container -weight: 500;">docker rm <container_id> # Remove stopped container -weight: 500;">docker rm myubuntu # Remove by name # STOP ALL containers at once -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # -q = quiet (only IDs) # REMOVE ALL containers -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all (running + stopped) # LIST downloaded images -weight: 500;">docker images # REMOVE an image -weight: 500;">docker rmi ubuntu # Remove ubuntu image -weight: 500;">docker rmi <image_id> # Remove by ID # Note: Must -weight: 500;">remove all containers using that image first! # LIST downloaded images -weight: 500;">docker images # REMOVE an image -weight: 500;">docker rmi ubuntu # Remove ubuntu image -weight: 500;">docker rmi <image_id> # Remove by ID # Note: Must -weight: 500;">remove all containers using that image first! # LIST downloaded images -weight: 500;">docker images # REMOVE an image -weight: 500;">docker rmi ubuntu # Remove ubuntu image -weight: 500;">docker rmi <image_id> # Remove by ID # Note: Must -weight: 500;">remove all containers using that image first! # ATTACH to a running container (connects to main process) -weight: 500;">docker attach test # CTRL+P then CTRL+Q = detach WITHOUT stopping container # If you type 'exit', container STOPS # EXEC runs a NEW process inside a running container -weight: 500;">docker exec -it test bash # If you type 'exit', only the exec process ends # The container keeps running! # ATTACH to a running container (connects to main process) -weight: 500;">docker attach test # CTRL+P then CTRL+Q = detach WITHOUT stopping container # If you type 'exit', container STOPS # EXEC runs a NEW process inside a running container -weight: 500;">docker exec -it test bash # If you type 'exit', only the exec process ends # The container keeps running! # ATTACH to a running container (connects to main process) -weight: 500;">docker attach test # CTRL+P then CTRL+Q = detach WITHOUT stopping container # If you type 'exit', container STOPS # EXEC runs a NEW process inside a running container -weight: 500;">docker exec -it test bash # If you type 'exit', only the exec process ends # The container keeps running! -weight: 500;">docker logs <container_id> # View container logs -weight: 500;">docker logs myubuntu -weight: 500;">docker inspect test # Full container details (JSON) -weight: 500;">docker inspect --format='{{.State.Status}}' test # Get specific info -weight: 500;">docker logs <container_id> # View container logs -weight: 500;">docker logs myubuntu -weight: 500;">docker inspect test # Full container details (JSON) -weight: 500;">docker inspect --format='{{.State.Status}}' test # Get specific info -weight: 500;">docker logs <container_id> # View container logs -weight: 500;">docker logs myubuntu -weight: 500;">docker inspect test # Full container details (JSON) -weight: 500;">docker inspect --format='{{.State.Status}}' test # Get specific info # Map host port 8081 to container port 80 -weight: 500;">docker run -d -p 8081:80 nginx # ^ ^ # | +-- container port (nginx listens on 80) # +-------- host port (access via localhost:8081) # Run multiple web servers on different ports -weight: 500;">docker run -d --name web1 -p 8081:80 ubuntu/apache2 -weight: 500;">docker run -d --name web2 -p 8082:80 ubuntu/apache2 # Access in browser: # http://localhost:8081 --> web1 # http://localhost:8082 --> web2 # Map host port 8081 to container port 80 -weight: 500;">docker run -d -p 8081:80 nginx # ^ ^ # | +-- container port (nginx listens on 80) # +-------- host port (access via localhost:8081) # Run multiple web servers on different ports -weight: 500;">docker run -d --name web1 -p 8081:80 ubuntu/apache2 -weight: 500;">docker run -d --name web2 -p 8082:80 ubuntu/apache2 # Access in browser: # http://localhost:8081 --> web1 # http://localhost:8082 --> web2 # Map host port 8081 to container port 80 -weight: 500;">docker run -d -p 8081:80 nginx # ^ ^ # | +-- container port (nginx listens on 80) # +-------- host port (access via localhost:8081) # Run multiple web servers on different ports -weight: 500;">docker run -d --name web1 -p 8081:80 ubuntu/apache2 -weight: 500;">docker run -d --name web2 -p 8082:80 ubuntu/apache2 # Access in browser: # http://localhost:8081 --> web1 # http://localhost:8082 --> web2 # Mount current directory into container -weight: 500;">docker run -it -v $(pwd):/scripts ubuntu bash # $(pwd) = your current directory on host # /scripts = path inside the container # Mount a specific file into nginx echo '<h1>Hello Docker!</h1>' > index.html -weight: 500;">docker run -d -p 8081:80 -v $(pwd)/index.html:/usr/share/nginx/html/index.html nginx # You have just hosted a simple web app! # Mount a Python script echo 'print("Hello, world!")' > hello.py -weight: 500;">docker run -it --rm -v $(pwd)/hello.py:/hello.py python:3.10-slim bash # Then inside: python hello.py # Mount current directory into container -weight: 500;">docker run -it -v $(pwd):/scripts ubuntu bash # $(pwd) = your current directory on host # /scripts = path inside the container # Mount a specific file into nginx echo '<h1>Hello Docker!</h1>' > index.html -weight: 500;">docker run -d -p 8081:80 -v $(pwd)/index.html:/usr/share/nginx/html/index.html nginx # You have just hosted a simple web app! # Mount a Python script echo 'print("Hello, world!")' > hello.py -weight: 500;">docker run -it --rm -v $(pwd)/hello.py:/hello.py python:3.10-slim bash # Then inside: python hello.py # Mount current directory into container -weight: 500;">docker run -it -v $(pwd):/scripts ubuntu bash # $(pwd) = your current directory on host # /scripts = path inside the container # Mount a specific file into nginx echo '<h1>Hello Docker!</h1>' > index.html -weight: 500;">docker run -d -p 8081:80 -v $(pwd)/index.html:/usr/share/nginx/html/index.html nginx # You have just hosted a simple web app! # Mount a Python script echo 'print("Hello, world!")' > hello.py -weight: 500;">docker run -it --rm -v $(pwd)/hello.py:/hello.py python:3.10-slim bash # Then inside: python hello.py -weight: 500;">systemctl -weight: 500;">start <-weight: 500;">service> # Start a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">stop <-weight: 500;">service> # Stop a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">restart <-weight: 500;">service> # Restart a -weight: 500;">service -weight: 500;">systemctl reload <-weight: 500;">service> # Reload config without stopping -weight: 500;">systemctl -weight: 500;">status <-weight: 500;">service> # Check if -weight: 500;">service is running -weight: 500;">systemctl -weight: 500;">enable <-weight: 500;">service> # Start on boot -weight: 500;">systemctl -weight: 500;">disable <-weight: 500;">service> # Don't -weight: 500;">start on boot -weight: 500;">systemctl -weight: 500;">start <-weight: 500;">service> # Start a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">stop <-weight: 500;">service> # Stop a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">restart <-weight: 500;">service> # Restart a -weight: 500;">service -weight: 500;">systemctl reload <-weight: 500;">service> # Reload config without stopping -weight: 500;">systemctl -weight: 500;">status <-weight: 500;">service> # Check if -weight: 500;">service is running -weight: 500;">systemctl -weight: 500;">enable <-weight: 500;">service> # Start on boot -weight: 500;">systemctl -weight: 500;">disable <-weight: 500;">service> # Don't -weight: 500;">start on boot -weight: 500;">systemctl -weight: 500;">start <-weight: 500;">service> # Start a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">stop <-weight: 500;">service> # Stop a -weight: 500;">service NOW -weight: 500;">systemctl -weight: 500;">restart <-weight: 500;">service> # Restart a -weight: 500;">service -weight: 500;">systemctl reload <-weight: 500;">service> # Reload config without stopping -weight: 500;">systemctl -weight: 500;">status <-weight: 500;">service> # Check if -weight: 500;">service is running -weight: 500;">systemctl -weight: 500;">enable <-weight: 500;">service> # Start on boot -weight: 500;">systemctl -weight: 500;">disable <-weight: 500;">service> # Don't -weight: 500;">start on boot 644 = rw-r--r-- # Standard file permission 755 = rwxr-xr-x # Standard directory / script permission 700 = rwx------ # Private (owner only) 600 = rw------- # SSH keys 777 = rwxrwxrwx # NEVER USE (security risk) 644 = rw-r--r-- # Standard file permission 755 = rwxr-xr-x # Standard directory / script permission 700 = rwx------ # Private (owner only) 600 = rw------- # SSH keys 777 = rwxrwxrwx # NEVER USE (security risk) 644 = rw-r--r-- # Standard file permission 755 = rwxr-xr-x # Standard directory / script permission 700 = rwx------ # Private (owner only) 600 = rw------- # SSH keys 777 = rwxrwxrwx # NEVER USE (security risk) -weight: 500;">docker run -it ubuntu bash # Interactive shell -weight: 500;">docker run -d -p 8080:80 nginx # Background + port map -weight: 500;">docker run -v $(pwd):/app ubuntu # Volume mount -weight: 500;">docker ps -a # List all containers -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # Stop all running -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all containers -weight: 500;">docker exec -it <id> bash # Shell into running container CTRL+P then CTRL+Q # Detach without stopping -weight: 500;">docker run -it ubuntu bash # Interactive shell -weight: 500;">docker run -d -p 8080:80 nginx # Background + port map -weight: 500;">docker run -v $(pwd):/app ubuntu # Volume mount -weight: 500;">docker ps -a # List all containers -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # Stop all running -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all containers -weight: 500;">docker exec -it <id> bash # Shell into running container CTRL+P then CTRL+Q # Detach without stopping -weight: 500;">docker run -it ubuntu bash # Interactive shell -weight: 500;">docker run -d -p 8080:80 nginx # Background + port map -weight: 500;">docker run -v $(pwd):/app ubuntu # Volume mount -weight: 500;">docker ps -a # List all containers -weight: 500;">docker -weight: 500;">stop $(-weight: 500;">docker ps -q) # Stop all running -weight: 500;">docker rm $(-weight: 500;">docker ps -aq) # Remove all containers -weight: 500;">docker exec -it <id> bash # Shell into running container CTRL+P then CTRL+Q # Detach without stopping #!/bin/bash # Shebang (always first line) $1 $2 $# $@ $? # Args, count, all, exit code read VAR # Read user input if [ condition ]; then ... fi # Conditional case "$1" in pattern) ... ;; esac # Flag handling for item in list; do ... done # Loop tar -czf name.tar.gz dir/ # Create archive awk '{print $1}' file # Text processing cat << EOF > file ... EOF # Heredoc command > file 2>&1 # Redirect all output #!/bin/bash # Shebang (always first line) $1 $2 $# $@ $? # Args, count, all, exit code read VAR # Read user input if [ condition ]; then ... fi # Conditional case "$1" in pattern) ... ;; esac # Flag handling for item in list; do ... done # Loop tar -czf name.tar.gz dir/ # Create archive awk '{print $1}' file # Text processing cat << EOF > file ... EOF # Heredoc command > file 2>&1 # Redirect all output #!/bin/bash # Shebang (always first line) $1 $2 $# $@ $? # Args, count, all, exit code read VAR # Read user input if [ condition ]; then ... fi # Conditional case "$1" in pattern) ... ;; esac # Flag handling for item in list; do ... done # Loop tar -czf name.tar.gz dir/ # Create archive awk '{print $1}' file # Text processing cat << EOF > file ... EOF # Heredoc command > file 2>&1 # Redirect all output - Linux Basics & File System - Linux Commands & Navigation - File Permissions & Ownership - Users & Groups Management - SSH (Secure Shell) - Apache Web Server - Nginx Web Server - Port Debugging & Troubleshooting - Bash Scripting - Docker Containers - Lab Exercises Summary - Quick Reference Cheat Sheet - Debian-based: Ubuntu, Debian — use .deb packages and -weight: 500;">apt package manager - Red Hat-based: CentOS, Fedora, RHEL — use .rpm packages and -weight: 500;">yum/-weight: 500;">dnf package manager - Technical differences are mainly about package management, software versions, and file locations - Once you grasp those differences, switching between distros becomes painless - What is the main function? (Server or Desktop?) - What packages are important? (web server, database, etc.) - How much disk space is available? - How often are packages updated? - How long is the support cycle? (LTS = Long Term Support) - Do you need long-term stability or cutting-edge software? - Absolute path: Starts from root /. Example: /usr/bin/python3 - Relative path: Starts from current directory. Example: ../usr/bin - User (u): The owner of the file. When you create a file, you become the owner. - Group (g): A collection of users. Useful in multi-user environments. - Other (o): Everyone else on the system. - /etc/passwd — Contains user account info (username:x:UID:GID:info:home:shell) - /etc/shadow — Contains encrypted passwords (only root can read) - /etc/group — Contains group definitions - Private key (~/.ssh/id_rsa): Stays on YOUR machine. NEVER share this! - Public key (~/.ssh/id_rsa.pub): Goes to the REMOTE server. - Default web root: /var/www/html/ (same as Apache) - Config files: /etc/nginx/sites-available/ and /etc/nginx/sites-enabled/ - Main config: /etc/nginx/nginx.conf - Default site config: /etc/nginx/sites-available/default - Image: A blueprint/template for a container (like a class in OOP). Downloaded from Docker Hub. - Container: A running instance of an image (like an object). You can run multiple from one image. - Docker Hub: Online registry of Docker images (like GitHub for images). - Tag: Version of an image. Example: ubuntu:22.04 vs ubuntu:latest