一、背景

Docker启动Tomcat默认是CMD ["catalina.sh", "run"]，日志将会托管给Docker容器，没有生成日志文件，只能使用命令docker logs -f <CONTAINER_ID>查看。

在Rancher平台部署服务，我们只能看到一部分日志，即使执行命令行进入tomcat的logs目录，也不到想要的日志，只能进入服务器查看容器日志。

只有使用startup.sh启动才会输出catalina.out。但是Docker如果以startup.sh启动，启动后会立即退出，这时Docker需要一个后台执行程序才会保持容器不退出。

二、开始制作Tomcat镜像

2.1 新建run.sh文件

使用startup.sh启动并一直tail -f catalina.out就不会退出容器，run.sh文件内容如下:

#! /bin/bash
bash /usr/local/tomcat/bin/startup.sh
tail -f /usr/local/tomcat/logs/catalina.out

2.2 新建Dockerfile文件

FROM lucksoft/tomcat:9-jdk8
ENV TZ Asia/Shanghai

WORKDIR /usr/local/tomcat

RUN apt-get install -y wget
RUN cp /etc/apt/sources.list /etc/apt/sources.list.bak

RUN echo "deb http://mirrors.aliyun.com/ubuntu/ xenial main >> /etc/apt/sources.list \
	echo "deb-src http://mirrors.aliyun.com/ubuntu/ xenial main >> /etc/apt/sources.list \
	echo "deb-src http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse >> /etc/apt/sources.list \
	echo "deb-src http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse >> /etc/apt/sources.list \
	echo "deb-src http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse >> /etc/apt/sources.list \
	echo "deb-src http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse12345678910 >> /etc/apt/sources.list \

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

RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    cron && \
    rm -rf /var/lib/apt/lists/* && \
    apt-get clean

COPY cut_log.sh /usr/local/tomcat/bin/

# 复制文件到容器内部的指定目录
COPY run.sh /usr/local/tomcat/bin/

# 赋予权限
RUN chmod 755 /usr/local/tomcat/bin/run.sh
RUN chmod 755 /usr/local/tomcat/bin/cut_log.sh

# 运行一次，设置定时任务
RUN echo "59 23 * * *  /usr/local/tomcat/bin/cut_log.sh" | crontab -

# run.sh启动
CMD ["/usr/local/tomcat/bin/run.sh"]

2.3 准备cut_log.sh文件

将日志文件进行归档整理。

#!/bin/bash

cd `dirname $0`

DATE=`date +%Y-%m-%d`

DATE30=`date -d '30 days ago' +%Y-%m-%d`

cd /usr/local/tomcat/logs

ls others >/dev/null  2>&1 

if [ $? != 0 ];then

  mkdir others

fi

# 前一天的日志移动到归档目录
find . -type f -mtime +1 -exec mv {} /usr/local/tomcat/logs/others/ \;
# 删除30天前的日志
find /usr/local/tomcat/logs/others -type f -mtime +30 -exec rm -f {} \;
cp /usr/local/tomcat/logs/catalina.out /usr/local/tomcat/logs/catalina.out.${DATE}

#清空
truncate -s 0 /usr/local/tomcat/logs/catalina.out

将上面的文件都放到同一个目录下，然后使用docker builder 命令构建镜像即可。