RHEL7系统使用cpanm安装Perl模块报错找不到模块求助

问题概述 #

• 需将原Docker容器化部署的Perl项目改造为物理机/虚拟机直接运行模式，原容器基于Ubuntu 20.04(focal)构建，当前部署环境为RHEL7
• 已尝试按原Dockerfile中Ubuntu的包名安装基础依赖，执行cpanm安装Perl模块时失败，典型报错如下：

[root@npcrver01 home]# cpanm Log::Log4perl
! Finding Log::Log4perl on cpanmetadb failed.
! cannot open file '/root/.cpanm/sources/http%www.cpan.org/02packages.details.txt.gz': No such file or directory opening compressed index
! Couldn't find module or a distribution Log::Log4perl ()

• 原项目Dockerfile逻辑如下：

FROM ubuntu:focal-20200703 as ubuntu
FROM ubuntu as mytool

ARG DEBIAN_FRONTEND=noninteractive
RUN apt-get update && apt-get install -y -qq build-essential libssl-dev tzdata bash curl wget perl cpanminus libcrypt-ssleay-perl libnet-ssleay-perl
RUN cpanm -n Data::Printer \
             Log::Log4perl \
             List::Util \
             Test::More \
             JSON \
             JSON::XS \
             YAML \
             YAML::XS \
             GitLab::API::v4 \
             IO::Socket::SSL \
             HTML::HashTable \
             REST::Client \
             MIME::Base64 \
             File::Spec \
             File::Basename \
             File::Path \
             List::MoreUtils \
             DateTime::Format::ISO8601 \
             Digest::MD5

ENV TZ=Pacific/Auckland
RUN echo $TZ > /etc/timezone && ln -snf /usr/share/zoneinfo/$TZ /etc/localtime

COPY docker/context/usr/local/bin/entrypoint.sh /usr/local/bin/entrypoint.sh
COPY docker/context/usr/local/etc/mytool/mytool.env.ctmpl /usr/local/etc/mytool/mytool.env.ctmpl

RUN mkdir -p /usr/local/bin /usr/local/bin/cache.d
WORKDIR /usr/local/bin

COPY mytool /usr/local/bin/
COPY lib/ /usr/local/bin/lib

# Container pilot obligatory parameters START
ENV SERVICE_NAME=mytool
ENV SERVICE_PRE_EXEC=/bin/true
ENV SERVICE_HEALTHCHECK_EXEC="test -f /usr/local/etc/mytool/mytool.env"
ENV SERVICE_TEMPLATE_CONFIG_PAIRS=/usr/local/etc/mytool/mytool.env.ctmpl:/usr/local/etc/mytool/mytool.env
EXPOSE 8080

ENTRYPOINT [""]
CMD ["/usr/local/bin/entrypoint.sh"]
# Container pilot obligatory parameters END

故障根因 #

• 两个发行版包命名规则完全不同，直接照搬Ubuntu的apt包名安装，会缺失大量编译Perl模块必需的系统依赖
• 默认cpanm配置使用海外CPAN源，受网络策略、防火墙限制无法拉取索引文件，且本地已生成损坏的缓存文件
• RHEL7默认源不带cpanminus包，手动安装的cpanm版本可能存在兼容问题

修复步骤 #

• 安装RHEL7适配的系统依赖
  不要使用Ubuntu的包名，执行以下命令安装所有系统级依赖：

  # 安装编译工具链（对应Ubuntu的build-essential）
  yum groupinstall -y "Development Tools"
  # 安装EPEL扩展源获取cpanminus包
  yum install -y epel-release
  # 安装所有编译、运行必需的系统包
  yum install -y openssl-devel perl-devel perl-CPAN zlib-devel wget curl tzdata bash perl-App-cpanminus
  

• 清理损坏缓存，重新安装Perl模块
  先删除旧的损坏cpanm缓存，指定可正常访问的CPAN镜像安装模块：

  # 清理旧缓存
  rm -rf /root/.cpanm
  # 批量安装所有需要的Perl模块
  cpanm --mirror https://mirrors.aliyun.com/CPAN/ -n Data::Printer \
               Log::Log4perl \
               List::Util \
               Test::More \
               JSON \
               JSON::XS \
               YAML \
               YAML::XS \
               GitLab::API::v4 \
               IO::Socket::SSL \
               HTML::HashTable \
               REST::Client \
               MIME::Base64 \
               File::Spec \
               File::Basename \
               File::Path \
               List::MoreUtils \
               DateTime::Format::ISO8601 \
               Digest::MD5
  

• 对齐容器内的目录与配置
  按照Dockerfile的路径映射规则，在服务器上创建对应目录、放置项目文件：

  # 创建所需目录
  mkdir -p /usr/local/bin/cache.d /usr/local/etc/mytool
  # 按原Dockerfile的COPY路径放置对应文件
  # 把entrypoint.sh放到/usr/local/bin/，加执行权限
  chmod +x /usr/local/bin/entrypoint.sh
  # 把mytool.env.ctmpl放到/usr/local/etc/mytool/
  # 把主程序mytool放到/usr/local/bin/
  # 把项目lib目录放到/usr/local/bin/下
  # 配置时区
  timedatectl set-timezone Pacific/Auckland
  

• 运行验证
  直接执行/usr/local/bin/entrypoint.sh启动脚本，无模块缺失、路径报错即为正常。原Dockerfile里的Container pilot相关配置是容器环境专用，物理机运行不需要部署，只要保证脚本运行时能正常生成/usr/local/etc/mytool/mytool.env配置文件即可，后续可自行配置systemd服务实现开机自启。

内容的提问来源于stack exchange，提问作者usert4jju7