The ppa:ondrej/php repository is maintained by Ondřej Surý, a Debian developer and PHP package maintainer. This PPA provides:

• Latest PHP versions not yet in official Ubuntu repositories
• Multiple PHP versions side-by-side installations
• Common extensions and dependencies

While the PPA is widely used, you should verify its components:

# List installed packages from the PPA
apt list --installed | grep ondrej

# Sample output:
# php8.1/now 8.1.2-1+ubuntu20.04.1+deb.sury.org+1 amd64 [installed,local]
# php8.1-cli/now 8.1.2-1+ubuntu20.04.1+deb.sury.org+1 amd64 [installed,local]

The repository does include numerous dependencies because PHP has many optional extensions. Common packages you might see include:

• libapache2-mod-php* - Apache integration
• php*-* - Various extensions (curl, gd, mysql, etc.)
• *-dev packages - Development headers

To safely use this PPA:

# 1. Verify package signatures
apt-key list | grep Ondřej

# 2. Pin specific versions if needed
echo "Package: php*
Pin: release o=LP-PPA-ondrej-php
Pin-Priority: 1001" | sudo tee /etc/apt/preferences.d/ondrej-php

For critical systems, consider:

• Using Docker containers with specific PHP images
• Setting up a private package mirror with only needed packages
• Regularly auditing installed packages with:

apt-get changelog php8.1 | head -n 20

If you need minimal installation:

# Install only specific PHP version and extensions
sudo apt install php8.1 php8.1-cli php8.1-common \
    php8.1-mysql php8.1-curl --no-install-recommends

The repository is generally safe when used properly, but always evaluate your specific security requirements.

The ppa:ondrej/php repository is maintained by Ondřej Surý, a Debian developer who provides up-to-date PHP packages for Ubuntu systems. This PPA is widely used in the PHP community because it offers:

• Newer PHP versions than official Ubuntu repositories
• Multiple PHP versions side-by-side
• Extensions not available in standard repos

When you run apt-get upgrade after adding this PPA, you might see many additional packages being installed. Let's examine some common ones:

# Typical additional packages you might see:
libapache2-mod-php8.1 
php8.1-cli 
php8.1-common 
php8.1-curl 
php8.1-gd 
php8.1-mysql 
php8.1-opcache 
php8.1-readline 
php8.1-xml

Before trusting any third-party repository, consider these security aspects:

# Verify the package signatures
apt-key list | grep -A1 "Ondřej Surý"

# Sample output should show:
# pub   rsa4096 2015-09-16 [SC]
#       14AA 40EC 0831 7567 56D7  F66C 4F4E A0AA E526 7A6C
# uid           [ unknown] Ondřej Surý <ondrej@debian.org>

For critical production systems, I recommend these precautions:

# 1. Pin specific PHP versions
sudo nano /etc/apt/preferences.d/php-pinning
# Add:
Package: php*
Pin: release o=LP-PPA-ondrej-php
Pin-Priority: 1001

# 2. Use Docker containers for isolation
docker run -it --rm ubuntu:20.04 bash -c \
"apt update && apt install -y software-properties-common && \
add-apt-repository ppa:ondrej/php -y && \
apt install -y php8.1"

To check what exactly changed in your system:

# List all PHP-related packages
dpkg -l | grep php | awk '{print $2}'

# Check modified configuration files
sudo find /etc -name "*.php" -type f -exec ls -la {} \;

# Verify package sources
apt-cache policy php8.1

If you're uncomfortable with the PPA, consider:

• Compiling PHP from source with only needed extensions
• Using official Docker PHP images (php:8.1-apache)
• Deploying via cloud provider's managed PHP services