1.下载jdk8   比如nacos会引用此变量

安装1.8.0的所有文件 yum install java-1.8.0-openjdk* -y 使用命令检查是否安装成功 java -version

  jdk自动安装目录为：/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64

  配置环境变量：

在 /etc/profile 文件中加入如下内容：

export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64

export JRE_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64

export CLASSPATH=.:$JAVA_HOME/jre/lib:$JAVA_HOME/lib

export PATH=$PATH:$JAVA_HOME/bin

执行下面命令使设置生效

source /etc/profile

下载tomcat8  暂不用

wget https://archive.apache.org/dist/tomcat/tomcat-8/v8.0.23/bin/apache-tomcat-8.0.23.tar.gz

2.创建dockerfile文件

FROM centos:latest#使用ADD指令会直接对jdk-8u141-linux-x64.tar.gz进行解压 不用单独的tar解压ADD jdk-8u141-linux-x64.tar.gz /usr/local/ENV JAVA_HOME /usr/local/jdk1.8.0_141ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jarENV PATH $PATH:$JAVA_HOME/bin

3.用dockerfile文件创建jdk镜像

[root@insure jdk8]# docker build -t jdk-8u141:20181222 . -f dockerfileSending build context to Docker daemon  185.5MBStep 1/5 : FROM centos:latest ---> 1e1148e4cc2cStep 2/5 : ADD jdk-8u141-linux-x64.tar.gz /usr/local/ ---> 65475cb92b9eStep 3/5 : ENV JAVA_HOME /usr/local/jdk1.8.0_141 ---> Running in 4537fa128bf8Removing intermediate container 4537fa128bf8 ---> a5ec3ad7eefdStep 4/5 : ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar ---> Running in 170040d357acRemoving intermediate container 170040d357ac ---> 70417d2b9cadStep 5/5 : ENV PATH $PATH:$JAVA_HOME/bin ---> Running in eacfe0487c6aRemoving intermediate container eacfe0487c6a ---> c717428b1276Successfully built c717428b1276Successfully tagged jdk-8u141:20181222[root@insure jdk8]# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED             SIZEjdk-8u141           20181222            c717428b1276        18 seconds ago      578MBcentos              latest              1e1148e4cc2c        2 weeks ago         202MBopenjdk             latest              8e7eacedab93        2 weeks ago         986MB

命令说明:使用-f 指定要使用的dockerfile，如果不指定会寻找当前目录名为dockerfile的文件 

 -t 指定镜像的名称和tag

4.运行创建的镜像

[root@insure jdk8]# docker run -d -it jdk-8u141:20181222 /bin/bash14c0f65b236c89c84723fe9e3f7011e405f388bf443608f054aaf24d5c290882[root@insure jdk8]# docker ps -aCONTAINER ID        IMAGE                COMMAND             CREATED             STATUS              PORTS               NAMES14c0f65b236c        jdk-8u141:20181222   "/bin/bash"         5 seconds ago       Up 4 seconds                            vigorous_yonath