在centos 7 的版本中默认有docker，只是版本有点老，但是初学的话，我感觉是可以直接使用的，应为redhat公司默认安装的软件，应该还是比较不错的。当然愿意尝鲜的话，安装也不难！这里
直接使用yum安装：
1. 安装
yum -y install docker
2. 目前centos7 的docker默认版本为
| [root@tomcat_jvm ~]# docker version Server: |
3. 由于网络环境因素，需要设置一下国内的镜像源，不然可能无法pull成功。
[root@tomcat_jvm system]# vim /etc/sysconfig/docker
| # /etc/sysconfig/docker # Modify these options if you want to change the way the docker daemon runs ##################################################重点在这里--registry-mirror=https://registry.docker-cn.com#########
|
4. 至此docker应该可以使用了，我们来启动一下docker。
[root@tomcat_jvm ~]# systemctl start docker.service
没有回显，就表示成功了，我们来看下状态：
| [root@tomcat_jvm ~]# systemctl status docker.service Apr 12 17:57:55 tomcat_jvm dockerd-current[5664]: time="2018-04-12T17:57:55.462419680+08:00" level=info msg="Firewalld running: false" |
启动成功了！
5. 设置socket 监听tcp端口：
由于这个版本的docker推荐将配置文件放到了/etc/docker/daemon.json 。（docker由于势头太猛，好多的配置都不太一样）
编辑配置文件，默认只用一对花括号：
{
"hosts": [
"tcp://0.0.0.0:2375",
"unix:///var/run/docker.sock"
]
}
6. 好的，设置完成，下面我们在重新启动一下docker服务
systemctl restart docker.service
ok，一样没有回显表示没有问题，下面我们来看一下服务器监听的端口：
[root@tomcat_jvm ~]# netstat -ntpl | grep docker
tcp6 0 0 :::2375 :::* LISTEN 5950/dockerd-curren
可以看到服务器已经监听到了tcp的2375号端口上了(端口可以随意设置，只要不和其他服务冲突即可)
7. 测试一下：
[root@tomcat_jvm ~]# curl 127.0.0.1:2375/info # 通过接口查看一下docker服务器的信息，返回的是一个json串
{"ID":"YDGP:5BGX:LNYB:P4LT:6X62:RJJ5:OSXV:XAAV:ZLXW:3KCS:Q7EA:H6FE","Containers":3,"ContainersRunning":0,"ContainersPaused":0,"ContainersStopped":3,"Images":3,"Driver":"overlay2","DriverStatus":[["Backing Filesy
stem","xfs"],["Supports d_type","false"],["Native Overlay Diff","true"]],"SystemStatus":null,"Plugins":{"Volume":["local"],"Network":["bridge","host","macvlan","null","overlay"],"Authorization":null},"MemoryLimit":true,"SwapLimit":true,"KernelMemory":true,"CpuCfsPeriod":true,"CpuCfsQuota":true,"CPUShares":true,"CPUSet":true,"IPv4Forwarding":true,"BridgeNfIptables":true,"BridgeNfIp6tables":true,"Debug":false,"NFd":15,"OomKillDisable":true,"NGoroutines":23,"SystemTime":"2018-04-12T18:10:03.909913989+08:00","LoggingDriver":"journald","CgroupDriver":"systemd","NEventsListener":0,"KernelVersion":"3.10.0-693.17.1.el7.x86_64","PkgVersion":"<unknown>","OperatingSystem":"CentOS Linux 7 (Core)","OSType":"linux","Architecture":"x86_64","IndexServerAddress":"https://index.docker.io/v1/","IndexServerName":"docker.io","RegistryConfig":{"InsecureRegistryCIDRs":["127.0.0.0/8"],"IndexConfigs":{"docker.io":{"Name":"docker.io","Mirrors":["https://registry.docker-cn.com/"],"Secure":true,"Official":true}},"Mirrors":["https://registry.docker-cn.com/"]},"NCPU":1,"MemTotal":1458810880,"DockerRootDir":"/var/lib/docker","HttpProxy":"","HttpsProxy":"","NoProxy":"","Name":"tomcat_jvm","Labels":null,"ExperimentalBuild":false,"ServerVersion":"1.13.1","ClusterStore":"","ClusterAdvertise":"","Runtimes":{"docker-runc":{"path":"/usr/libexec/docker/docker-runc-current"},"runc":{"path":"docker-runc"}},"DefaultRuntime":"docker-runc","Swarm":{"NodeID":"","NodeAddr":"","LocalNodeState":"inactive","ControlAvailable":false,"Error":"","RemoteManagers":null,"Nodes":0,"Managers":0,"Cluster":{"ID":"","Version":{},"CreatedAt":"0001-01-01T00:00:00Z","UpdatedAt":"0001-01-01T00:00:00Z","Spec":{"Orchestration":{},"Raft":{"ElectionTick":0,"HeartbeatTick":0},"Dispatcher":{},"CAConfig":{},"TaskDefaults":{},"EncryptionConfig":{"AutoLockManagers":false}}}},"LiveRestoreEnabled":false,"Isolation":"","InitBinary":"docker-init","ContainerdCommit":{"ID":"","Expected":"aa8187dbd3b7ad67d8e5e3a15115d3eef43a7ed1"},"RuncCommit":{"ID":"N/A","Expected":"9df8b306d01f59d3a8029be411de015b7304dd8f"},"InitCommit":{"ID":"N/A","Expected":"949e6facb77383876aeff8a6944dde66b3089574"},"SecurityOptions":["name=seccomp,profile=/etc/docker/seccomp.json"],"Registries":[{"Name":"docker.io","Secure":true}]}