Docker构建Jenkins镜像时npm安装失败求助

我尝试编写Dockerfile，在容器中安装Jenkins、Chrome、Node.js和npm，基于Jenkins官方基础镜像构建，添加了Chrome和Node.js的安装步骤，Dockerfile内容如下：

FROM jenkins/jenkins:2.440.1-jdk17
USER root

# Update and install necessary packages
RUN apt-get update && \
    apt-get install -y lsb-release wget gnupg2 apt-transport-https curl

# Add Docker official GPG key
RUN curl -fsSLo /usr/share/keyrings/docker-archive-keyring.asc \
    https://download.docker.com/linux/debian/gpg

# Set up Docker repository
RUN echo "deb [arch=$(dpkg --print-architecture) \
    signed-by=/usr/share/keyrings/docker-archive-keyring.asc] \
    https://download.docker.com/linux/debian \
    $(lsb_release -cs) stable" > /etc/apt/sources.list.d/docker.list

# Install Docker CLI
RUN apt-get update && apt-get install -y docker-ce-cli

# Add Google Chrome repository and install Chrome
RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
    echo "deb [arch=$(dpkg --print-architecture)] http://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list && \
    apt-get update && apt-get install -y google-chrome-stable

# Install Node.js and npm
RUN curl -fsSL https://deb.nodesource.com/setup_14.x | bash - && \
    apt-get update && apt-get install -y nodejs && \
    npm install -g npm@latest

# Verify Node.js and npm installation
RUN node --version && npm --version

# Clean up
RUN apt-get clean && rm -rf /var/lib/apt/lists/*

USER jenkins

# Install Jenkins plugins
RUN jenkins-plugin-cli --plugins "blueocean docker-workflow"

执行构建命令 docker build -t my-jenkins . 时出现错误：

91.92 /bin/sh: 1: npm: not found
------
Dockerfile:27
--------------------
  26 |     # Install Node.js and npm
  27 | >>> RUN curl -fsSL https://deb.nodesource.com/setup_14.x | bash - && \
  28 | >>>     apt-get update && apt-get install -y nodejs && \
  29 | >>>     npm install -g npm@latest
  30 |
--------------------
ERROR: failed to solve: process "/bin/sh -c curl -fsSL https://deb.nodesource.com/setup_14.x | bash - &&     apt-get update && apt-get install -y nodejs &&     npm install -g npm@latest" did not complete successfully: exit code: 127

原因 #

同一个RUN指令中的所有命令在同一个shell进程中执行。通过apt-get install -y nodejs安装npm后，当前shell的PATH环境变量并未刷新，无法识别新安装的npm可执行文件路径，因此执行npm命令时提示"not found"。

另外，Node.js 14已处于生命周期结束（End-of-Life）状态，存在安全隐患，建议升级至长期支持（LTS）版本（如20.x）。

修复步骤 #

1. 拆分npm升级命令到单独的RUN指令
   将安装Node.js和升级npm的操作拆分为两个独立的RUN，新的shell进程会重新读取系统环境变量，从而识别npm的路径：

   # Install Node.js and npm（升级到20.x LTS版本）
   RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
       apt-get update && apt-get install -y nodejs
   
   # Upgrade npm to latest version
   RUN npm install -g npm@latest
   

2. 可选：使用npm绝对路径
   如果不想拆分RUN指令，可以直接使用npm的绝对路径（通常为/usr/bin/npm或/usr/local/bin/npm）：

   RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
       apt-get update && apt-get install -y nodejs && \
       /usr/bin/npm install -g npm@latest
   

3. 验证安装
   原有的验证命令RUN node --version && npm --version可以保留，用于确认Node.js和npm安装成功。

修改后的完整Dockerfile #

FROM jenkins/jenkins:2.440.1-jdk17
USER root

# Update and install necessary packages
RUN apt-get update && \
    apt-get install -y lsb-release wget gnupg2 apt-transport-https curl

# Add Docker official GPG key
RUN curl -fsSLo /usr/share/keyrings/docker-archive-keyring.asc \
    https://download.docker.com/linux/debian/gpg

# Set up Docker repository
RUN echo "deb [arch=$(dpkg --print-architecture) \
    signed-by=/usr/share/keyrings/docker-archive-keyring.asc] \
    https://download.docker.com/linux/debian \
    $(lsb_release -cs) stable" > /etc/apt/sources.list.d/docker.list

# Install Docker CLI
RUN apt-get update && apt-get install -y docker-ce-cli

# Add Google Chrome repository and install Chrome
RUN wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
    echo "deb [arch=$(dpkg --print-architecture)] http://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list && \
    apt-get update && apt-get install -y google-chrome-stable

# Install Node.js and npm（使用20.x LTS版本）
RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
    apt-get update && apt-get install -y nodejs

# Upgrade npm to latest version
RUN npm install -g npm@latest

# Verify Node.js and npm installation
RUN node --version && npm --version

# Clean up
RUN apt-get clean && rm -rf /var/lib/apt/lists/*

USER jenkins

# Install Jenkins plugins
RUN jenkins-plugin-cli --plugins "blueocean docker-workflow"

内容的提问来源于stack exchange，提问作者Jeff