目的
由开发环境交测的时候，通过docker镜像简化环境搭建及项目部署的过程。
环境描述
项目开发环境: windowns7
在windowns7中通过VMware Workstation安装CentOS 7
在CentOS 7中安装docker
docker配置
1.docker正常安装。通过yum安装后最终信息如下：
[samhxm@localhost app]$ sudo docker version
Client:
Version: 1.12.3
API version: 1.24
Go version: go1.6.3
Git commit: 6b644ec
Built:
OS/Arch: linux/amd64
Server:
Version: 1.12.3
API version: 1.24
Go version: go1.6.3
Git commit: 6b644ec
Built:
OS/Arch: linux/amd64
2.docker开启远程API。
通过yum安装的docker配置文件是/lib/systemd/system/docker.service
修改该文件的ExecStart参数为加入/usr/bin/dockerd -H TCP://0.0.0.0:2375 -H UNIX:///VAR/RUN/DOCKER.SOCK 最终配置如下：
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network.target
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H TCP://0.0.0.0:2375 -H UNIX:///VAR/RUN/DOCKER.SOCK
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
[Install]
WantedBy=multi-user.target
3.重启docker
[samhxm@localhost ~]$ sudo systemctl daemon-reload
[samhxm@localhost ~]$ sudo systemctl restart docker
4.获取包含jre的基础镜像。如果仅仅是运行java程序，镜像中包含jre即可。我使用的是daocloud的java镜像。如果项目中需要其他环境依赖(数据库，MQ，Redis等)可以事先自行构建一个包含所需环境的镜像。
[root@localhost ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
daocloud.io/library/java latest 861e95c114d6 4 weeks ago 643.1 MB
daocloud.io/library/mysql latest cf725f136fd2 7 weeks ago 383.4 MB
maven项目pom.xml配置
在项目的pom.xml中加入docker-maven-plugin插件,根据项目实际情况进行设置。
com.spotify
docker-maven-plugin
0.4.13
http://192.168.1.107:2375
sam/spring-boot-dockerimage
daocloud.io/library/java:latest
["java", "-jar", "/${project.build.finalName}.jar"]
/
${project.build.directory}
${project.build.finalName}.jar
配置项说明：
dockerHost: docker宿主机地址，其中端口号为docker远程API访问端口。
imageName: 构建镜像的repository,该值勿包含英文大写字母。
baseImage: 基础镜像。基于该镜像构建项目的运行环境。
entryPoint: 同dockerfile中的命令，还可以写其他在dockerfile中运行的命令。
resources: 项目的资源配置
运行maven命令构建项目，并生成docker镜像
E:\workspace2\dockerImage>mvn clean package docker:build
其中关键信息如下：
[INFO] Copying E:\workspace2\dockerImage\target\dockerimage.jar -> E:\workspace2\dockerImage\target\docker\dockerimage.jar
[INFO] Building image sam/spring-boot-dockerimage
Step 1 : FROM daocloud.io/library/java:latest
---> 861e95c114d6
Step 2 : ADD /dockerimage.jar //
---> d401cb3c9dfd
Removing intermediate container 49fcdc6cb81e
Step 3 : ENTRYPOINT java -jar /dockerimage.jar
---> Running in dd5ed0604906
---> a295878e59f6
Removing intermediate container dd5ed0604906
Successfully built a295878e59f6
[INFO] Built sam/spring-boot-dockerimage
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 24.871 s
[INFO] Finished at: 2016-12-10T17:18:55+08:00
[INFO] Final Memory: 29M/466M
[INFO] ------------------------------------------------------------------------
检查docker宿主机是否已产生镜像
[root@localhost ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
sam/spring-boot-dockerimage latest 804270c5ba56 7 seconds ago 658.9 MB
daocloud.io/library/java latest 861e95c114d6 4 weeks ago 643.1 MB
daocloud.io/library/mysql latest cf725f136fd2 7 weeks ago 383.4 MB
启动镜像
[samhxm@localhost ~]$ sudo docker run -it -p 8080:8080 sam/spring-boot-dockerimage:latest /bin/bash
通过docker宿主机ip和8080端口即可访问项目。