Dockerfile

ARG PHP_VERSION=7.4
FROM php:${PHP_VERSION}-cli-alpine as php_build

ADD https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions /usr/local/bin/

RUN chmod +x /usr/local/bin/install-php-extensions; \
    apk add --update binutils; \
    install-php-extensions \
        ast \
        xdebug \
        zip \
        pcntl \
        grpc \
        protobuf \
        sockets \
        intl \
        @composer \
    ; \
    # strip debug symbols from extensions to reduce size
    find /usr/local/lib/php/extensions -name "*.so" -exec strip --strip-debug {} \;;

FROM php_build

WORKDIR /usr/src/myapp

RUN   apk add --no-cache bash git; \
      find /usr/local/lib/php/extensions -type d -exec chmod +x -R {} \;; \
      addgroup -g "1000" -S php; \
      adduser --system \
        --gecos "" \
        --ingroup "php" \
        --uid "1000" \
        "php";

USER php