dockerfile里面的内容编写顺序，必须严格按照顺序编写，否则编译不成

完整文档请参照https://www.cnblogs.com/effortsing/p/10480972.html 这里只介绍dockerfile里面的步骤顺序


cat>/home/jenkins-dockerfile/Dockerfile <<EOF
FROM jenkinsci/jenkins
USER root
RUN apt-get update && apt-get install -y libltdl7.*
RUN apt-get install vim* -y
ADD apache-maven-3.5.4-bin.tar.gz /usr/local/
ENV MAVEN_HOME=/usr/local/apache-maven-3.5.4
ENV PATH=$JAVA_HOME/bin:$MAVEN_HOME/bin:$PATH
ARG dockerGid=999
RUN echo "docker:x:${dockerGid}:jenkins" >> /etc/group
RUN echo "jenkins ALL=NOPASSWD: ALL" >> /etc/sudoers
EOF


上面Dockerfile中必须先执行apt-get update && apt-get install -y libltdl7.*，再安装maven，添加环境变量，否则编译会报如下错误：

debconf: delaying package configuration, since apt-utils is not installed
dpkg: warning: 'ldconfig' not found in PATH or not executable
dpkg: warning: 'start-stop-daemon' not found in PATH or not executable
E: Sub-process /usr/bin/dpkg returned an error code (2)
The command '/bin/sh -c apt-get update && apt-get install -y libltdl7.*' returned a non-zero code: 100