For long testing and building I have acceptable Docker container about PHP 8.0.0 FPM with a lot of modules loaded.
FROM php:8.0.0-fpm-alpine
######## [PHP Modules] Default ########
#### Core
#### ctype
#### curl
#### date
#### dom
#### fileinfo
#### filter
#### ftp
#### hash
#### iconv
#### json
#### libxml
#### mbstring
#### mysqlnd
#### openssl
#### pcre
#### PDO
#### pdo_sqlite
#### Phar
#### posix
#### readline
#### Reflection
#### session
#### SimpleXML
#### sodium
#### SPL
#### sqlite3
#### standard
#### tokenizer
#### xml
#### xmlreader
#### xmlwriter
#### zlib
######## Composer.phar ########
RUN curl -s https://getcomposer.org/installer | php \
# move composer into a bin directory you control:
&& mv composer.phar /usr/local/bin/composer \
# double check composer works
&& composer about
RUN php -m && echo "============================================="
######## Dependencies ########
#### bzip2-dev: bz2
#### enchant2-dev: enchant
#### gd: libpng-dev
#### gmp: gmp-dev
#### imap: imap-dev
#### intl: icu-dev
#### ldap: openldap-dev
#### pdo_dblib: freetds-dev
#### pdo_pgsql: postgresql-dev
#### pgsql: postgresql-dev
#### pspell: aspell-dev
#### snmp: net-snmp-dev
#### soap: libxml2-dev
#### tidy: tidyhtml-dev
#### xsl: libxslt-dev
#### zip: libzip-dev
RUN apk add --no-cache --update \
bzip2-dev \
enchant2-dev \
libpng-dev \
gmp-dev \
imap-dev \
icu-dev \
openldap-dev \
freetds-dev \
postgresql-dev \
aspell-dev \
net-snmp-dev \
libxml2-dev \
tidyhtml-dev \
libxslt-dev \
libzip-dev
RUN docker-php-ext-install \
bcmath \
bz2 \
calendar \
dba \
enchant \
exif \
ffi \
gd \
gettext \
gmp \
imap \
intl \
ldap \
mysqli \
opcache \
pcntl \
pdo_dblib \
pdo_mysql \
pdo_pgsql \
pgsql \
pspell \
shmop \
snmp \
soap \
sockets \
sysvmsg \
sysvsem \
sysvshm \
tidy \
xsl \
zend_test \
zip
######## PHP MODULES not working yet ########
#### oci8
#### odbc
#### pdo_firebird
#### pdo_oci
#### pdo_odbc
RUN rm -rf /tmp/* /var/cache/apk/* \
&& echo "=============================================" \
&& php -m
8.0.0-fpm-ext-alpine.Dockerfile