Docker安装初试&&制作centos6.5基础镜像

https://blog.tankywoo.com/docker/2014/05/08/docker-4-summary.html
https://yeasy.gitbooks.io/docker_practice/content/basic_concept/container.html
centos7.x系列的yum源中自带了docker的rpm包，安装比较简单
# yum install docker -y
安装过程中可能会遇到lvm2包依赖冲突，如不使用，卸载即可
# yum remove lvm2
启动服务
# service docker start
查看版本
# docker -v
Docker version 1.10.3, build d381c64-unsupported
获取BusyBox镜像
# docker pull busybox
创建容器并echo一句话
# docker run busybox /bin/echo Starting docker trip?
Starting docker trip?
centos6.x系列需要安装epel源，并且升级内核到3.10版本否则docker不能正常运行
基于git克隆安装https://github.com/llitfkitfk/docker-tutorial-cn

# git clone git://github.com/llitfkitfk/docker-tutorial-cn.git
# cd docker-tutorial-cn/
# ./docker_install.sh 
##执行此步骤如果报下文错误需要修改/etc/yum.repos.d/epel.repo文件，取消baseurl的注释，注释掉mirrorlist
Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again
# ./docker_config.sh  ##可根据实际情况修改docker image的储存路径，此处配置到/mnt/docker，默认路径是/var/lib/docker 
# mkdir /mnt/docker
# ./start_docker.sh   ##开启docker服务
docker: relocation error: docker: symbol dm_task_get_info_with_deferred_remove, version Base not defined in file libdevmapper.so.1.02 with link time reference
# yum upgrade device-mapper-libs   ##启动报错，需要安装依赖
# docker info         ##检查Docker是否正确安装
Containers: 0
Images: 0
Storage Driver: devicemapper
 Pool Name: docker-253:0-1182180-pool
 Pool Blocksize: 65.54 kB
 Backing Filesystem: extfs
 Data file: /dev/loop0
 Metadata file: /dev/loop1
 Data Space Used: 305.7 MB
 Data Space Total: 107.4 GB
 Data Space Available: 28.35 GB
 Metadata Space Used: 733.2 kB
 Metadata Space Total: 2.147 GB
 Metadata Space Available: 2.147 GB
 Udev Sync Supported: true
 Deferred Removal Enabled: false
 Data loop file: /var/lib/docker/devicemapper/devicemapper/data
 Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
 Library Version: 1.02.117-RHEL6 (2016-04-01)
Execution Driver: native-0.2
Logging Driver: json-file
Kernel Version: 2.6.32-358.6.2.el6.x86_64
Operating System: 
CPUs: 12
Total Memory: 3.662 GiB
Name: localhost
ID: SAJR:3GXN:LA3H:XV3F:4WUS:PJNS:N7YI:IXS2:LCO2:J6WL:AMCV:AEBW

在docker index中搜索centos相关的image
# docker search centos
从docker registry server拉取centos镜像
# docker pull centos
创建一个运行bash应用的容器，一直报错，使用-d命令查看进行运行信息，发现内核版本过低

# docker run -i -t centos /bin/bash
Error response from daemon: Cannot start container 317bcef4837ad90112a9021012f243bdf92e594h file or directory
# docker -d
WARN[0000] You are running linux kernel version 2.6.32-358.6.2.el6.x86_64, which might be pgrade your kernel to 3.10.0.

于是升级内核到3.10
http://my.oschina.net/denglz/blog/487332
安装kernel-lt（long-term）

# yum install http://www.elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm
# yum --enablerepo=elrepo-kernel install kernel-lt -y

新安装的内核已经自动写入了grub.conf文件，只需修改Grub引导顺序，重启即可
# sed -i 's/default=1/default=0/' /etc/grub.conf

内核已经更新

# uname -a
Linux localhost.localdomain 3.10.102-1.el6.elrepo.x86_64 #1 SMP Tue Jun 14 11:40:50 EDT 20

列出images

# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
centos              latest              d83a55af4e75        2 weeks ago         196.7 MB

使用centos这个镜像创建container进入交互模式，login shell是/bin/bash

Docker制作centos6.5基础镜像
http://blog.chinaunix.net/uid-20788636-id-4909654.html

# yum install febootstrap
# mkdir /dockerimg/centos6.5  创建镜像文件保存目录
# febootstrap -i bash -i wget -i yum -i iputils -i iproute -i man -i vim -i openssh-server -i openssh-clients -i tar -i p7zip -i net-tools  centos6.5 /dockerimg/centos6.5 http://vault.centos.org/6.5/os/x86_64/
-i指定安装的包     centos6.5标识OS版本
# cp /etc/skel/.bash* /dockerimg/centos6.5/root/
# cd /dockerimg/centos6.5
# tar -c .|docker import - centos6.5   导入镜像文件
63a8a89d802130fa35f0661402bf776069dcfd2cf83da553d4874c6a6c7ad056
# docker images   已经成功导入，使用docker run命令就可以基于centos6.5创建容器使用了
REPOSITORY          TAG                 IMAGE ID            CREATED              VIRTUAL SIZE
centos6.5           latest              63a8a89d8021        About a minute ago   372 MB