---

如果需要一个定时任务的模板系统，可以使用如下的Dockerfile构建镜像

对大小有一些要求，可以试试基于 Alpine 构建的镜像 docker-alpine-cron

# Backup Server 
# Version 1.0
# Explain: crond
# Author: dongdong
# Date: 2017-12-29

FROM centos
USER root

# 使用阿里源替换默认源
RUN mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
RUN yum clean all && yum makecache

# 安装 cronie
RUN yum -y install cronie && yum clean all && rm -rf /var/cache/yum

# 调整时区
RUN cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

# 按照正常方式启动crond时，会报错：docker cron FAILED to open PAM security session
RUN sed -i -e '/pam_loginuid.so/s/^/#/' /etc/pam.d/crond

# 添加定时任务
RUN chmod 0644 /etc/crontab
RUN echo "*/1 * * * * root /bin/echo 'it works' >> /root/test.log" >> /etc/crontab

CMD crond && tail -f /dev/null

在定时任务镜像的基础上，扩充功能，实现使用数据库客户端备份数据的目的

PS：需要先有一个正常工作的备份数据库shell脚本

# Backup Server 
# Version 1.0
# Explain: oracle & mysql backup with crond
# Author: dongdong
# Date: 2017-12-29

FROM centos

USER root

# 使用阿里源替换默认源
RUN mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
RUN curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
RUN yum clean all && yum makecache

# 安装一些常用软件
#RUN yum -y install epel-release && yum makecache
RUN yum -y install vim unzip cronie expect openssh-clients libaio && yum clean all && rm -rf /var/cache/yum

# 调整时区
RUN cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

# 添加本地目录的文件到镜像中
ADD sh /home/sh
ADD downloads /home/downloads
ADD conf /home/conf
RUN mkdir /home/log && mkdir /home/data

# 安装 MySQL
RUN ["rpm", "-ivh", "/home/downloads/mysql-community-common-5.7.19-1.el7.x86_64.rpm"]
RUN ["rpm", "-ivh", "/home/downloads/mysql-community-libs-5.7.19-1.el7.x86_64.rpm"]
RUN ["rpm", "-ivh", "/home/downloads/mysql-community-client-5.7.19-1.el7.x86_64.rpm"]

# 安装 Oracle 客户端
RUN unzip /home/downloads/oracle-instantclient11.2-basic-11.2.0.1.0-1.x86_64.zip -d /home/oracle 
RUN unzip /home/downloads/oracle-instantclient11.2-jdbc-11.2.0.1.0-1.x86_64.zip -d /home/oracle
RUN unzip /home/downloads/oracle-instantclient11.2-sdk-11.2.0.1.0-1.x86_64.zip -d /home/oracle
RUN unzip /home/downloads/oracle-instantclient11.2-sqlplus-11.2.0.1.0-1.x86_64.zip -d /home/oracle
RUN cp -R /home/downloads/instantclient_11_2_exp_imp/* /home/oracle/instantclient_11_2
RUN cp /home/conf/tnsnames.ora /home/oracle/instantclient_11_2
RUN chmod +x /home/oracle/instantclient_11_2/imp /home/oracle/instantclient_11_2/exp

# 安装完成客户端后删除安装包
RUN rm -rf /home/downloads

# 设置 Oracle 的环境变量
RUN echo $'export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK\n\
export ORACLE_IC_HOME=/home/oracle/instantclient_11_2\n\
export ORACLE_HOME=$ORACLE_IC_HOME\n\
export TNS_ADMIN=$ORACLE_IC_HOME\n\
export PATH=$PATH:$HOME/bin:$ORACLE_IC_HOME\n\
export LD_LIBRARY_PATH=$ORACLE_IC_HOME:/usr/lib\n\
export ORACLE_SID=ZFGFH' >> /root/.bash_profile

#RUN ["/bin/bash", "-c", "source /root/.bash_profile"]


# comment out pam
RUN sed -i -e '/pam_loginuid.so/s/^/#/' /etc/pam.d/crond

RUN chmod 0644 /etc/crontab


# 添加定时任务
RUN echo "*/1 * * * * root /bin/echo 'it works' >> /root/test.log" >> /etc/crontab
RUN echo "30 22 * * * root source /root/.bash_profile; /bin/expect /home/sh/backup_zfgfh.sh >> /home/log/zfgfh.log" >> /etc/crontab


CMD crond && tail -f /dev/null