Docker jdk拆分部署tomcat/jenkins

Docker jdk拆分部署tomcat/jenkins

试想下，如果可以让多个java应用共享相同的jdk，那对于空间和管理上都是极大的方便的，实际上docker本身就有这种功能

环境:

CentOS 7

jdk1.8

tomcat9

jenkins-2.7.1

docker-engine-1.11.2

1.jdk镜像

mkdir /docker_tmp

curl http://download.oracle.com/otn-pub/java/jdk/8u92-b14/jdk-8u92-linux-x64.tar.gz |tar -zxvf - -C /docker_tmp

mv /docker_tmp/jdk1.8.0_92/ /docker_tmp/jdk

cd /docker_tmp

cat >Dockerfile <<HERE

FROM busybox

MAINTAINER Jlive Liu "iliujun_live@163.com"

LABEL Description="jdk volume" Vendor="Jlive" Version="1.8"

VOLUME ["/opt/jdk"]

ADD . /opt

HERE

docker build -t jdk1.8 .

提示:VOLUME一定要标明，否则tomcat等应用无法挂载，当然也可以直接通过映射本地的jdk给到java容器

root@router:docker#docker build -t jdk1.8 .

Sending build context to Docker daemon 366.3 MB

Step 1 : FROM busybox

 ---> 2b8fd9751c4c

Step 2 : MAINTAINER Jlive Liu "iliujun_live@163.com"

 ---> Running in 119edb8e2e06

 ---> cf23614e0267

Removing intermediate container 119edb8e2e06

Step 3 : LABEL Description "jdk volume" Vendor "Jlive" Version "1.8"

 ---> Running in deb99e7bd0bf

 ---> 95a32896c940

Removing intermediate container deb99e7bd0bf

Step 4 : ADD . /opt

 ---> bf8026d1f466

Removing intermediate container 0192f52ac659

Successfully built bf8026d1f466

root@router:docker#docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

jdk1.8              latest              bf8026d1f466        3 seconds ago       366.1 MB

2.tomcat镜像

rm -rf /docker_tmp/*

curl http://apache.fayea.com/tomcat/tomcat-9/v9.0.0.M8/bin/apache-tomcat-9.0.0.M8.tar.gz |tar -zxvf - -C /docker_tmp

mv /docker_tmp/apache-tomcat-9.0.0.M8/ /docker_tmp /tomcat

cd /docker_tmp

cat >Dockerfile <<HERE

FROM ubuntu:14.04

MAINTAINER "Jlive Liu"

LABEL Description="Apache tomcat" Vendor="Jlive" Version="9"

ADD . /opt

# Define ENV

ENV LANG=C.UTF-8

ENV CATALINA_HOME=/opt/tomcat

ENV PATH=$CATALINA_HOME/bin:$PATH

# Exporse ports

EXPOSE 8080 

# Volume

VOLUME ["$CATALINA_HOME/conf","$CATALINA_HOME/logs","$CATALINA_HOME/webapps","$CATALINA_HOME/work"]

# Define entrypoint

ENTRYPOINT ["catalina.sh", "run"]

HERE

docker build -t tomcat9 .

root@router:hello#ls

Dockerfile  tomcat/

root@router:hello#docker build -t tomcat9 .

Sending build context to Docker daemon 13.54 MB

Step 1 : FROM busybox

 ---> 2b8fd9751c4c

Step 2 : MAINTAINER Jlive Liu "iliujun_live@163.com"

 ---> Using cache

 ---> cf23614e0267

Step 3 : LABEL Description "tomcat image" Vendor "Jlive" Version "9"

 ---> Running in ba6062d0c446

 ---> c48539035ef3

Removing intermediate container ba6062d0c446

Step 4 : ADD ./tomcat /opt

 ---> 00c17f172892

Removing intermediate container 57df6d279975

Step 5 : ENV CATALINA_HOME /opt/tomcat

 ---> Running in 6a7b7a72ae8c

 ---> 5a7985a3d994

Removing intermediate container 6a7b7a72ae8c

Step 6 : ENV PATH $CATALINA_HOME/bin:$PATH

 ---> Running in 378a772abd7c

 ---> e2c75bbc7079

Removing intermediate container 378a772abd7c

Step 7 : EXPOSE 8080

 ---> Running in 209a3dfcd502

 ---> cd643ba3f4ed

Removing intermediate container 209a3dfcd502

Step 8 : VOLUME $CATALINA_HOME/conf $CATALINA_HOME/logs $CATALINA_HOME/webapps $CATALINA_HOME/work

 ---> Running in ca0c8314da0f

 ---> fea57546a257

Removing intermediate container ca0c8314da0f

Step 9 : ENTRYPOINT catalina.sh start

 ---> Running in 3f5bf58e7a57

 ---> 60da4a5c7203

Removing intermediate container 3f5bf58e7a57

Successfully built 60da4a5c7203

root@router:hello#docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

tomcat9             latest              fa1a3de66f7c        About a minute ago   228.4 MB

jdk1.8              latest              bf8026d1f466        47 minutes ago      366.1 MB

busybox             latest              2b8fd9751c4c        2 weeks ago         1.093 MB

3.运行tomcat

docker run -tid --restart=always --name jdk1.8 jdk1.8

docker run -tid --restart=always

    -e JAVA_HOME=/opt/jdk

    --volumes-from jdk1.8

    --name mytomcat

    tomcat9 

mkdir -p /opt/tomcat

docker cp mytomcat:/opt/tomcat/conf /opt/tomcat/

docker rm -f mytomcat

为了最大程度的可定制性，可以将配置文件，log等目录映射到本地，当然如果应用比较固定统一则可以直接固化到image里

docker run -tid --restart=always

    -e JAVA_HOME=/opt/jdk

    -e JAVA_OPTS="-Xms1536m -Xmx1536m -XX:MaxPermSize=512m"

    -p 8080:8080

    --memory-swappiness=1

    --ulimit nofile=20480:40960

    --volumes-from jdk1.8

    -v /opt/tomcat/conf:/opt/tomcat/conf

    -v /opt/tomcat/logs:/opt/tomcat/logs

    --name mytomcat

    tomcat9

提示:还可以加上shell

docker run -tid --restart=always --name shell busybox

    --volumes-from shell

4.部署应用

以war包应用为例，测试这里用jenkins

i.代码打包为docker volume

rm -rf /docker_tmp/*

cd /docker_tmp

curl http://ftp.tsukuba.wide.ad.jp/software/jenkins/war-stable/2.7.1/jenkins.war -o /tmp/jenkins.war

mkdir jenkins

unzip /tmp/jenkins.war -d jenkins

cat >Dockerfile <<HERE

FROM busybox

MAINTAINER "Jlive Liu"

LABEL Description="jenkins" Vendor="Jlive" Version="2.7.1"

VOLUME ["/opt/tomcat/webapps/jenkins"]

RUN mkdir -p /opt/tomcat/webapps

ADD . /opt/tomcat/webapps

HERE

docker build -t jenkins .

注意:jenkins只是tomcat中的一个应用，打包时是精细打包，所以挂载卷的时只会把/opt/tomcat/webapps/jenkins挂到/opt/tomcat/webapps下，tomcat默认的demo是不会覆盖的

正常环境下，应该是通过ant脚本等自动编译打包工具将代码自动打成war包，再将war包打成docker volume发布

root@router:webapps#docker build -t jenkins .

Sending build context to Docker daemon 81.66 MB

Step 1 : FROM busybox

 ---> 2b8fd9751c4c

Step 2 : MAINTAINER "Jlive Liu"

 ---> Using cache

 ---> b967b67fc736

Step 3 : LABEL Description "jenkins" Vendor "Jlive" Version "2.7.1"

 ---> Using cache

 ---> 1bae96ee2100

Step 4 : VOLUME /opt/tomcat/webapps/jenkins

 ---> Using cache

 ---> 8dd4d9ab79d2

Step 5 : RUN mkdir -p /opt/tomcat/webapps

 ---> Using cache

 ---> d06a04c638c2

Step 6 : ADD . /opt/tomcat/webapps

 ---> 573ad293c3d5

Removing intermediate container 4dd659de46c6

 

Successfully built 573ad293c3d5

提示:便于批量部署，建议将打包好的代码上传到docker-distribution

ii.发布代码

docker run -tid --restart=always --name app jenkins

docker rm -f mytomcat

docker run -tid --restart=always

    -e JAVA_HOME=/opt/jdk

    -e JAVA_OPTS="-Xms1536m -Xmx1536m -XX:MaxPermSize=512m"

    -p 8080:8080

    --memory-swappiness=1

    --ulimit nofile=20480:40960

    --volumes-from jdk1.8

    --volumes-from app 

    -v /opt/tomcat/conf:/opt/tomcat/conf

    -v /opt/tomcat/logs:/opt/tomcat/logs

    --name mytomcat

    tomcat9

root@router:webapps#docker cp mytomcat:/root/.jenkins/secrets/initialAdminPassword .

root@router:webapps#cat initialAdminPassword 

895fff6eed77400fb5ba1aa45bc22dca

jenkins-2.7.1更新比较大，UI方面更加清爽，和最新的zabbix3.x的感觉类似,初始化时是随机密码，并且生成在docker里，所以需要进入docker或cp出来查看

国内安装jenkins插件不容易，可以将容器commit为image

root@router:webapps#docker commit -m "init ok" app app_init

sha256:3460468153aa55c93fba8cefe318bedd08fd8b1a52e7738ee3b6680aed74a5ac

root@router:webapps#docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

app_init            latest              3460468153aa        4 seconds ago       69.94 MB

jenkins             latest              573ad293c3d5        46 minutes ago      81.77 MB