Docker部署Laravel项目时安装PHP8.1出现依赖错误求助

问题场景 #

使用Docker部署Laravel项目时，执行apt-get install安装PHP8.1相关扩展失败，此前相同配置可正常运行，已执行docker system prune -a和重装Docker，问题仍存在。

错误信息 #

=> ERROR [14/26] RUN apt-get install -y     php8.1-fpm     php8.1-common     php8.1-curl     php8.1-mysql     php8.1-mbstring     php8.1-xml     php8.1-bcmath     php8.1-gd     php8.1-xdebug     php8.1-soap     php8  2.3s 
------
 > [14/26] RUN apt-get install -y     php8.1-fpm     php8.1-common     php8.1-curl     php8.1-mysql     php8.1-mbstring     php8.1-xml     php8.1-bcmath     php8.1-gd     php8.1-xdebug     php8.1-soap     php8.1-zip:       
#18 0.621 Reading package lists...
#18 1.822 Building dependency tree...
#18 2.008 Reading state information...
#18 2.106 Some packages could not be installed. This may mean that you have
#18 2.106 requested an impossible situation or if you are using the unstable
#18 2.106 distribution that some required packages have not yet been created
#18 2.106 or been moved out of Incoming.
#18 2.106 The following information may help to resolve the situation:
#18 2.106
#18 2.106 The following packages have unmet dependencies:
#18 2.255  php8.1-fpm : Depends: systemd but it is not going to be installed or
#18 2.255                        systemd-tmpfiles but it is not installable
#18 2.275 E: Unable to correct problems, you have held broken packages.
------
executor failed running [/bin/sh -c apt-get install -y     php8.1-fpm     php8.1-common     php8.1-curl     php8.1-mysql     php8.1-mbstring     php8.1-xml     php8.1-bcmath     php8.1-gd     php8.1-xdebug     php8.1-soap  
   php8.1-zip]: exit code: 100

关联Dockerfile内容 #

#------------- Setup Environment -------------------------------------------------------------

# Pull base image
FROM ubuntu:18.04
ENV TZ=America/Sao_Paulo
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

# Install common tools 
RUN apt-get update
RUN apt-get install -y wget curl nano htop git unzip bzip2 software-properties-common locales

# Set evn var to enable xterm terminal
ENV TERM=xterm

# Set working directory
WORKDIR /var/www/html

COPY . ./

# Add repositories
RUN LC_ALL=C.UTF-8 apt-add-repository ppa:ondrej/php
RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys ABF5BD827BD9BF62
RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4F4EA0AAE5267A6C
RUN echo "deb http://nginx.org/packages/ubuntu/ trusty nginx" >> /etc/apt/sources.list
RUN echo "deb-src http://nginx.org/packages/ubuntu/ trusty nginx" >> /etc/apt/sources.list

RUN apt-get update

#------------- Application Specific Stuff ----------------------------------------------------

# Install PHP
RUN apt-get update
RUN apt-get install -y \
    php8.1-fpm \
    php8.1-common \
    php8.1-curl \
    php8.1-mysql \
    php8.1-mbstring \
    php8.1-xml \
    php8.1-bcmath \
    php8.1-gd \
    php8.1-xdebug \
    php8.1-soap \
    php8.1-zip   

RUN echo "xdebug.mode=develop" >> /etc/php/8.1/mods-available/xdebug.ini

#------------- FPM & Nginx configuration ----------------------------------------------------

# Config fpm to use TCP instead of unix socket
ADD docker/www.conf /etc/php/8.1/fpm/pool.d/www.conf
RUN mkdir -p /var/run/php

# Install Nginx
RUN apt-get install -y nginx

ADD docker/game /etc/nginx/sites-enabled/

ADD docker/nginx.conf /etc/nginx/

#------------- Composer & laravel configuration ----------------------------------------------------

# Install composer
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer

#------------- Supervisor Process Manager ----------------------------------------------------

# Install supervisor
RUN apt-get install -y supervisor
RUN mkdir -p /var/log/supervisor
ADD docker/supervisord.conf /etc/supervisor/conf.d/supervisord.conf

#------------- Container Config ---------------------------------------------------------------
ARG ENV_KEY=dev

COPY ./.${ENV_KEY}.env ./.env

RUN chown -R www-data:www-data ./

# Expose port 80
EXPOSE 80

# Set supervisor to manage container processes
ENTRYPOINT ["/usr/bin/supervisord"]

解决建议 #

• 替换基础镜像为支持PHP8.1的Ubuntu版本：Ubuntu 18.04已终止标准支持，ondrej/php PPA对其的PHP8.1支持可能已移除，建议替换为Ubuntu 20.04或更高版本：

  FROM ubuntu:20.04
  

• 修复Nginx仓库配置：当前使用的trusty版本仓库与Ubuntu 18.04/20.04不兼容，需修改为对应版本的仓库（以Ubuntu20.04为例）：

  RUN echo "deb http://nginx.org/packages/ubuntu/ focal nginx" >> /etc/apt/sources.list
  RUN echo "deb-src http://nginx.org/packages/ubuntu/ focal nginx" >> /etc/apt/sources.list
  

• 手动安装缺失依赖（仅适用于坚持用Ubuntu18.04的场景）：强制安装systemd和systemd-tmpfiles后再安装PHP扩展：

  RUN apt-get install -y systemd systemd-tmpfiles
  

• 使用官方PHP-FPM镜像：直接基于php:8.1-fpm镜像构建，避免手动处理依赖问题，简化Dockerfile配置。
• 清理缓存后重新构建：执行以下命令彻底清理镜像缓存并重新构建：

  docker build --no-cache .
  

内容的提问来源于stack exchange，提问作者JohnSan