GitHub SSH key available on the server so you can git pull (or push) securely via SSH — and keep it working after reboots.

• Copy your private SSH key for github to your server scp ~/.ssh/id_rsa root@164.125.1251:~/.ssh/github_id_rsa
• On the server set strict permissions cmod 600 ~/.ssh/github_id_rsa
• Create or update your SSh config on the server sudo nano ~/.ssh/config
• add this:

Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/github_id_rsa
    IdentitiesOnly yes

• Make sure the SSH agent loads your key on login. Add this to server's ~/.bashrc or ~/.bash_profile

# Start ssh-agent if not running, and add GitHub key
if ! pgrep -u "$USER" ssh-agent > /dev/null; then
    eval "$(ssh-agent -s)"
    ssh-add ~/.ssh/github_id_rsa
fi

• test this setup when logged in to your server run ssh -T git@github.com
• you should see welcome message from GitHub.

Enable a new virtual host site and install Certbot

• make sure that A record for domain and www is pointing to the correct IP
• when the virtual host file is ready yoursite.conf enable it
• a2ensite yoursite.conf
• check the apache syntax apache2ctl configtest and reload apache
• sudo certbot --apache -d yoursite.com -d www.yoursite.com
• if certbot fails run sudo certbot --apache --debug-challenges
• or list all loaded vhosts apache2ctl -S

MySQL settings a new user and new database

• create a new user mysql -uroot -p
• list all users SELECT User, Host FROM mysql.user;

-- Create the user
CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'user_password';

-- Grant all privileges on a specific database
GRANT ALL PRIVILEGES ON database_name.* TO 'newuser'@'localhost';

-- Apply changes
FLUSH PRIVILEGES;

• import db mysql -u username -p database_name < /path/to/your/file.sql

Extend the terminal idle time / disable automatic logout

• change the sshd config sudo nano /etc/ssh/sshd_config
• add or modify the following
• Time (in seconds) between server checks to see if the client is still connected. ClientAliveInterval 0
• Number of server checks before considering the session dead. Setting this to 0 means the server will not check. ClientAliveCountMax 0
• restart the ssh service systemctl restart ssh or systemctl restart sshd

TAR with GZ

• make a tar with gz tar -czvf archive.tar.gz -C /path/to/directory .
• extract the tar.gz to specific location tar -xzvf archive.tar.gz -C /your/target/directory/
• tar with gz and specify multiple directories that you want to skip tar -czf archive.tar.gz --exclude='folder1' --exclude='folder2' --exclude='path/to/folder3' my_project/ path is relative from where you do the tar command, so no need for full path like /var/www/websitename
• to extract tar.gz file tar -xzvf your_file.tar.gz
• to extract to specific location tar -xzvf your_file.tar.gz -C /path/to/destination/

Automated backup with cron

• set up a cron task crontab -e
• example of task at 4am every morning

# m h  dom mon dow   command
# everyday at 4 am and save output in a log file
0 4 * * * /var/www/totwebsite/wp-content/themes/maivdigital/db/db_dump_cron.sh >> /var/www/totwebsite/wp-content/themes/maivdigital/db/dailylogfile.log 2>&1 

Truncate the logfile

#!/bin/bash

LOG_FILE="dailylog.log"
MAX_SIZE=2  # Max file size in MB

# Check if the file exists
if [ -f "$LOG_FILE" ]; then
    # Get the file size in MB
    FILE_SIZE_MB=$(du -m "$LOG_FILE" | cut -f1)

    echo "File '$LOG_FILE' exists. Size: ${FILE_SIZE_MB}MB"

    # Check if the file size is greater than the max size
    if [ "$FILE_SIZE_MB" -gt "$MAX_SIZE" ]; then
        echo "File size exceeds ${MAX_SIZE}MB. Truncating..."
        > "$LOG_FILE"
        echo "File truncated."
    else
        echo "File size is within the limit."
    fi
else
    echo "File '$LOG_FILE' not found."
fi

List files in MB

• ls -lh
• ls -lh | awk '{print $5, $9}'
• du -ah --max-depth=1 | awk '{printf "%.2f MB\t%s\n", $1/1024, $2}'

Change the default Ubuntu file type color display

• check if the default color is set echo $LS_COLORS
• check if any color is assigned for a specific filetype. example .log file type

echo $LS_COLORS | grep -oE '\*\.log=[^:]+' || echo "No color set for .log files"

• create custom .dircolors file

• create a copy of the default color settings dircolors -p > ~/.dircolors

• edit .dircolors with you own colors

• example .log 04;33 - will create bold underlined yellow color for .log file type

• more color codes: - 31 → Red

    - 32 → Green
  
    - 34 → Blue
  
    - 35 → Magenta
  
    - 36 → Cyan
  
    - 90 → Gray (default for backup files)
  

• apply new color eval "$(dircolors -b ~/.dircolors)"

• source ~/.bashrc

Increase the File size upload limit

• run this to locate the loaded php configuration file
• php --ini | grep "Loaded Configuration File"
• this should display this file /etc/php/your-version/php.ini , also check this path /etc/php/your-version/apache2/php.ini
• look for variable upload_max_filesize
• restart apache systemctl restart apache2

Fresh Ubuntu install is missing Imagick or GD PHP extensions

• this needs to be installed in Ubuntu
• apt install php-imagick and apt install php-gd
• installation for a specific PHP version apt install php8.0-imagick php8.0-gd
• systemctl restart apache2

DB Search & Replace WP CLI

• use the WP CLI commands to perform search & replace
• This command performs search and replace with addition flags and stores the results in the separate file
• Instead of applying changes to the live database, it exports the modified SQL to a new path specified below. Live database remains unchanged.
• wp search-replace 'old_string' 'new_string' --precise --all-tables --export=path/to/your/file.sql

Ubuntu server Alias settings

alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'
alias cls='clear'
alias showmb='du -ah --max-depth=1 | awk "{printf "%.2f MB\t%s\n", $1/1024, $2}"'

# Apache
alias atest='apache2ctl configtest'
alias astatus='systemctl status apache2'
alias areload='systemctl reload apache2'
alias arestart='systemctl restart apache2'

# Git 
alias gs='git status'
alias pull='git pull'
alias push='git push origin master'
alias commit='git commit -m "update"'