简单介绍一下Dockerfile：
FROM centos:7 表示依赖centos:7版本的镜像，如果没有对应的镜像，会自动拉去最新的cenos:7镜像
RUN yum -y install libxml2 表示执行某一条命令
ENV 表示构建镜像过程中的环境变量，执行的时候可用
ENTRYPOINT 表示类似CMD命令，执行某条指令，比如执行nginx：ENTRYPOINT [ "nginx", "-g", "daemon off;" ]
好了解释完了基本命令，现在来构建一个php环境的镜像。
创建Dockerfile文件，输入以下内容：
FROM centos:7 ENV PHP_INI_DIR /usr/local/php/etc RUN yum -y install libxml2 libxml2-devel openssl openssl-devel curl-devel libjpeg-devel libpng-devel freetype-devel libmcrypt-devel libzip-devel pcre-devel RUN yum install -y https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/o/oniguruma-6.8.2-1.el7.x86_64.rpm RUN yum install -y https://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/o/oniguruma-devel-6.8.2-1.el7.x86_64.rpm RUN cd /tmp RUN wget wget https://www.php.net/distributions/php-7.4.7.tar.xz && xz -d php-7.4.7.tar.xz && tar -xvf php-7.4.7.tar RUN ./configure --with-config-file-path="$PHP_INI_DIR" --with-pear --enable-bcmath --with-curl --enable-gd --with-libdir=lib64 --with-bz2 --with-zlib --enable-soap --enable-sockets --with-mysqli --with-pdo-mysql --with-curl --enable-fpm --enable-mbstring --enable-sockets --enable-gd --with-openssl RUN make && make install RUN cp /tmp/php-7.4.7/php.ini-production /usr/local/php/etc/php.ini # 如有需要可以打开 # RUN cp /usr/local/php/etc/php-fpm.conf.default /usr/local/php/etc/php-fpm.conf # RUN cp /usr/local/php/etc/php-fpm.d/www.conf.default /usr/local/php/etc/php-fpm.d/www.conf RUN sed -i "s/memory_limit = 128M/memory_limit = 1024M/g" /usr/local/php/etc/php.ini
RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" &&
php composer-setup.php &&
php -r "unlink('composer-setup.php');" &&
mv composer.phar /usr/local/bin/composer &&
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer
RUN pecl channel-update pecl.php.net
RUN pecl install -o -f redis && echo extension=redis.so >> /usr/local/php/etc/php.ini
ENTRYPOINT []
WORKDIR /workdir
进入Dockerfile目录，执行docker build .
等待镜像构建，至此，php环境的镜像就完成了