Centos7安装Docker 基于Dockerfile 搭建httpd运行环境
Centos7安装Docker 基于Dockerfile 搭建httpd运行环境docker
docker搭建
docker build本文档完成目标内容如下
使用Docker搭建http服务器一台。
要求搭建完成后映射docker80端口。httpd页面显示自己的名字和IP地址
CentOS 7 下Docker的安装
[*] Docker简介
Docker 是一个开源的应用容器引擎，让开发者可以打包他们的应用以及依赖包到一个可移植的容器中，然后发布到任何流行的 Linux 机器上，也可以实现虚拟化。容器是完全使用沙箱机制，相互之间不会有任何接口。Docker 使用客户端-服务器 (C/S) 架构模式，使用远程API来管理和创建Docker容器。Docker 容器通过 Docker 镜像来创建。容器与镜像的关系类似于面向对象编程中的对象与类。官网地址：http://www.docker.com/
[*] docker所需环境准备
系统要求CentOS 7.X 以上版本，内核至少3.10，64-bit
[*]uname -r //查看内核
[*]3.10.0-327.el7.x86_64
[*]yum update //升级本地yum包
创建docker的yum库
[*]# cd /etc/yum.repos.d/ && vi docker.repo
[*]
[*]
[*]name=DockerRepository
[*]baseurl=https://yum.dockerproject.org/repo/main/centos/7
[*]enabled=1
[*]gpgcheck=1
[*]gpgkey=https://yum.dockerproject.org/gpg
安装docker
[*]yum install docker-io
启动docker服务并设置开机自动启动
[*]systemctl start docker.service
[*]systemctl enable docker.service
[*]Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
验证docker是否安装成功
[*]docker info
[*]Containers: 0
[*] Running: 0
[*] Paused: 0
[*] Stopped: 0
[*]Images: 0
[*]Server Version: 1.10.3
[*]Storage Driver: devicemapper
[*] Pool Name: docker-253:0-34868263-pool
[*] Pool Blocksize: 65.54 kB
[*] Base Device Size: 10.74 GB
[*] Backing Filesystem: xfs
[*] Data file: /dev/loop0
[*] Metadata file: /dev/loop1
[*] Data Space Used: 11.8 MB
[*] Data Space Total: 107.4 GB
[*] Data Space Available: 26.96 GB
[*] Metadata Space Used: 581.6 kB
[*] Metadata Space Total: 2.147 GB
[*] Metadata Space Available: 2.147 GB
[*] Udev Sync Supported: true
[*] Deferred Removal Enabled: false
[*] Deferred Deletion Enabled: false
[*] Deferred Deleted Device Count: 0
[*] Data loop file: /var/lib/docker/devicemapper/devicemapper/data
[*] WARNING: Usage of loopback devices is strongly discouraged for production use. Either use `--storage-opt dm.thinpooldev` or use `--storage-opt dm.no_warn_on_loop_devices=true` to suppress this warning.
[*] Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
[*] Library Version: 1.02.135-RHEL7 (2016-09-28)
[*]Execution Driver: native-0.2
[*]Logging Driver: journald
[*]Plugins:
[*] Volume: local
[*] Network: host bridge null
[*]Kernel Version: 3.10.0-327.el7.x86_64
[*]Operating System: CentOS Linux 7 (Core)
[*]OSType: linux
[*]Architecture: x86_64
[*]Number of Docker Hooks: 2
[*]CPUs: 2
[*]Total Memory: 3.86 GiB
[*]Name: localhost.localdomain
[*]ID: WZJQ:VTFD:LVRA:SSU3:MFNC:75V3:JEZT:KTVR:HF2G:WXR5:34AR:N2N5
[*]WARNING: bridge-nf-call-iptables is disabled
[*]WARNING: bridge-nf-call-ip6tables is disabled
[*]Registries: docker.io (secure)
查看安装后的docker版本
[*]docker version
[*]Client:
[*] Version: 1.10.3
[*] API version: 1.22
[*] Package version: docker-common-1.10.3-59.el7.centos.x86_64
[*] Go version: go1.6.3
[*] Git commit: 3999ccb-unsupported
[*] Built: Thu Dec 15 17:24:43 2016
[*] OS/Arch: linux/amd64
[*]
[*]Server:
[*] Version: 1.10.3
[*] API version: 1.22
[*] Package version: docker-common-1.10.3-59.el7.centos.x86_64
[*] Go version: go1.6.3
[*] Git commit: 3999ccb-unsupported
[*] Built: Thu Dec 15 17:24:43 2016
[*] OS/Arch: linux/amd64
3.编写Dockerfile
Dockfile是一种被Docker程序解释的脚本，Dockerfile由一条一条的指令组成，每条指令对应Linux下面的一条命令。Docker程序将这些Dockerfile指令翻译真正的Linux命令。Dockerfile有自己书写格式和支持的命令，Docker程序解决这些命令间的依赖关系，类似于Makefile。Docker程序将读取Dockerfile，根据指令生成定制的image。相比image这种黑盒子，Dockerfile这种显而易见的脚本更容易被使用者接受，它明确的表明image是怎么产生的。有了Dockerfile，当我们需要定制自己额外的需求时，只需在Dockerfile上添加或者修改指令，重新生成image即可，省去了敲命令的麻烦。
3.1 Docker加速器
之所以提到这个是因为，在build镜像的过程中需要从服务器pull images,但是不幸的的Docker官网已经被墙，所以需要借助国内第三方,我使用的阿里云的。
安装或升级Docker
您可以通过阿里云的镜像仓库下载： mirrors.aliyun.com/help/docker-engine
curl -sSL http://acs-public-mirror.oss-cn-hangzhou.aliyuncs.com/docker-engine/internet | sh -
配置Docker加速器
您可以使用如下的脚本将mirror的配置添加到docker daemon的启动参数中。
系统要求 CentOS 7 以上，Docker 1.9 以上。
[*]sudo sed -i "s|ExecStart=/usr/bin/docker daemon|ExecStart=/usr/bin/docker daemon --registry-mirror=https://g9d5s6dr.mirror.aliyuncs.com|g"
[*]sudo systemctl daemon-reload
[*]sudo service docker restart
Dockerfile文件内容如下：
[*]FROM centos:centos6
[*]MAINTAINER liuqiang <402588603@qq.com>
[*]RUN yum -y update; yum clean all
[*]RUN yum -y install httpd && yum clean all
[*]RUN touch/var/www/html/index.html
[*]RUN echo "I have finished, pls give me five!!!! --liuqiang " >>
[*]/var/www/html/index.html
[*]EXPOSE 80
[*]#Simple startup script to avoid some issues observed with container restart
[*]ADD run-httpd.sh /run-httpd.sh//注意脚本目录
[*]RUN chmod -v +x /run-httpd.sh//赋予脚本执行权限
[*]CMD ["/run-httpd.sh"]
run-httpd.sh脚本内容如下
[*]cat >> run-httpd.sh << EOF
[*]#!/bin/bash
[*]# Make sure we're not confused by old, incompletely-shutdown httpd
[*]# context after restarting the container.httpd won't start correctly
[*]# if it thinks it is already running.
[*]rm -rf /run/httpd/*
[*]exec /usr/sbin/apachectl -D FOREGROUND
[*]EOF
注意：Dockerfile需借助脚本来重启httpd服务，并且最好放置于同一目录
[*]docker build-t liuqiang/httpd:centos6 .
[*]flag provided but not defined: -it
[*]See '/usr/bin/docker-current --help'.
[*]dockerbuild -t liuqiang/httpd .
[*]Sending build context to Docker daemon5.12 kB
[*]Step 1 : FROM centos:centos6
[*] ---> 8315978ceaaa
[*]Step 2 : MAINTAINER liuqiang <402588603@qq.com>
[*] ---> Using cache
[*] ---> 658aeb6d114a
[*]Step 3 : RUN yum -y update; yum clean all
[*] ---> Using cache
[*] ---> 8f1c933b2c3c
[*]Step 4 : RUN yum -y install httpd && yum clean all
[*] ---> Using cache
[*] ---> 98ee768720c7
[*]Step 5 : RUN touch/var/www/html/index.html
[*] ---> Using cache
[*] ---> b69a69656752
[*]Step 6 : RUN echo "I have finished, pls give me five!!!! --liuqiang" >> /var/www/html/index.html
[*] ---> Using cache
[*] ---> b4c9fd4843fb
[*]Step 7 : EXPOSE 80
[*] ---> Using cache
[*] ---> e4b5491564c2
[*]Step 8 : ADD run-httpd.sh /run-httpd.sh
[*] ---> Using cache
[*] ---> ed7ec84907d1
[*]Step 9 : RUN chmod -v +x /run-httpd.sh
[*] ---> Using cache
[*] ---> 081c6a101c16
[*]Step 10 : CMD /run-httpd.sh
[*] ---> Using cache
[*] ---> 15eaa6d6d407
[*]Successfully built 15eaa6d6d407
此时通过Dockerfile创建的镜像已经创建成功，并无报错
接下来运行容器
docker run -it -p 80:80 liuqiang/httpd:centos6
docker: Error response from daemon: failed to create endpoint clever_keller on network bridge: Error starting userland proxy: listen tcp 0.0.0.0:80: bind: address already in use.
启动
[*]docker run -d -p 80:80 liuqiang/httpd:centos6
[*]0582508431eb5713c1401843e68cb36b51de3bdd23dfa468cbe7496d71091e25
[*]curl http://localhost
[*]I have finished, pls give me five!!!! --liuqiang//curl测试成功
浏览器测试确认下
页:
[1]