Improve generation of required php extensions

[hostep]

Bug report

Description

The list of required php extensions in https://devdocs.magento.com/guides/v2.4/install-gde/system-requirements-tech.html#required-php-extensions is not accurate.

Currently it's generated from the composer.json file of the latest Magento version, but that's not accurate enough since all its dependency packages are not taken into account.

I suggested a possible solution in #7398 (comment) (also #7398 (comment)) to get a more accurate list, maybe someone can try that and see if that works and then somehow try to automate this.

Steps to reproduce

1. Look at list of php extensions on https://devdocs.magento.com/guides/v2.4/install-gde/system-requirements-tech.html#required-php-extensions

Expected result

1. Finding ext-sockets which became required in Magento 2.4.0

Possible solutions

1. Not finding ext-sockets which became required in Magento 2.4.0

Additional information

This issue was opened at the request of @dshevtsov

[m2-assistant]

Hi @hostep. Thank you for your report.
To help us process this issue please make sure that you provided sufficient information.

Please, add a comment to assign the issue: @magento I am working on this

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[dshevtsov]

Related PR with a workaround: #7953

[dshevtsov]

The input I've got from the packaging team:

the best and the only correct way is rely on the composer.json. Dependency on ext-sockets came from another dependency of Magento php-amqplib/php-amqplib. We should not document dynamic dependencies.
If we have real dependency on ext-sockets in the code and don’t have it in the composer.json - this needs to be fixed

[hostep]

Sorry, but that's just incorrect, Magento code strongly relies on code in the dependent packages, so their dependencies are implicitly also dependencies Magento needs.

Just try executing composer install with Magento 2.4.0 on a system where only the php extensions listed in the composer.json file are installed, it's not going to work.

[hostep]

Code of Magento and code called in its dependencies might not need ext-sockets, but composer will not allow you to install Magento if the required dependencies (including php extensions) aren't installed. Therefore we should document all php extensions required to be able to install Magento.

[dshevtsov]

cc @fascinosum

[dshevtsov]

Just try executing composer install with Magento 2.4.0 on a system where only the php extensions listed in the composer.json file are installed, it's not going to work.

In DevDocs, we use a Docker project that reproduces Magento installation using Composer on an environment with listed prerequisites to test the documentation. Here is the script for an environment setup for 2.4.0.

#!/bin/bash
set -x
apt-get update
export DEBIAN_FRONTEND=noninteractive


# INSTALL MAIN TOOLS
# https://help.ubuntu.com/community/ApacheMySQLPHP
apt-get install -y  curl \
                    git \
                    mysql-server \
                    php \
                    software-properties-common \
                    unzip \
                    vim \
                    wget

# INSTALL PHP EXTENSIONS
# Required: https://devdocs.magento.com/guides/v2.4/install-gde/system-requirements-tech.html#required-php-extensions
# Available: 'apt-cache search php7.4'
# Installation details:
#   ctype: selecting 'php7.4-common' instead of 'php7.4-ctype'
#   dom: selecting 'php7.4-xml' instead of 'php7.4-dom'
#   hash: As of PHP 5.1.2, the Hash extension is bundled and compiled into PHP by default.
#   iconv: System: Note, selecting 'php7.4-common' instead of 'php7.4-iconv'
#   openssl: Already present and enabled in the system: 'php --ri openssl'
#   pdo_mysql: https://www.php.net/manual/en/ref.pdo-mysql.php
#   simplexml: selecting 'php7.4-xml' instead of 'php7.4-simplexml'
#   xsl: installed with 'php7.4-xml'

apt-get install -y  php-bcmath \
                    php-curl \
                    php-xml \
                    php-gd \
                    php-intl \
                    php-mbstring \
                    php-mysql \
                    php-soap \
                    php-zip

# INSTALL ELASTICSEARCH
# https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | apt-key add -
apt-get install apt-transport-https
echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | tee -a /etc/apt/sources.list.d/elastic-7.x.list
apt-get update
apt-get install elasticsearch

# INSTALL COMPOSER GLOBALLY
# https://getcomposer.org/doc/faqs/how-to-install-composer-programmatically.md
EXPECTED_CHECKSUM="$(wget -q -O - https://composer.github.io/installer.sig)"
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
ACTUAL_CHECKSUM="$(php -r "echo hash_file('sha384', 'composer-setup.php');")"

if [ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]
then
    >&2 echo 'ERROR: Invalid installer checksum'
    rm composer-setup.php
    exit 1
fi

php composer-setup.php --quiet
RESULT=$?
rm composer-setup.php
mv composer.phar /usr/local/bin/composer

exit $RESULT

[dshevtsov]

It's for ubuntu 20.04