本章将介绍在阿里云的 Centos6.5 模板上安装 Docker 以及在 Ubuntu 14.04 模板上安装 Docker 的过程

Centos 6.5 模板上使用Docker

首先，通过 ssh 登陆阿里云的服务器，查看系统版本号以及内核版本。Welcome to aliyun Elastic Compute Service! # lsb_release -a LSB Version: :base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch Distributor ID: CentOS Description: CentOS release 6.5 (Final) Release: 6.5 Codename: Final # uname -a Linux xxxxxxx 2.6.32-431.23.3.el6.x86_64 #1 SMP Thu Jul 31 17:20:51 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

升级内核

因为 Docker 推荐使用 3.8 以上内核，所以我们选择使用 YUM 方式来升级内核。导入 KEY ,安装软件源。在 YUM 的 ELRepo 源中，有 mainline（3.13.1）、long-term（3.10.28）这 2 个内核版本，考虑到 long-term 更稳定，会长期更新，所以选择这个版本。# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org # yum --enablerepo=elrepo-kernel install kernel-lt -y Loaded plugins: security base | 3.7 kB 00:00 base/primary_db | 4.6 MB 00:00 elrepo | 2.9 kB 00:00 elrepo/primary_db | 709 kB 00:46 elrepo-kernel | 2.9 kB 00:00 elrepo-kernel/primary_db | 20 kB 00:01 epel | 4.4 kB 00:00 epel/primary_db | 6.3 MB 00:01 extras | 3.4 kB 00:00 extras/primary_db | 29 kB 00:00 updates | 3.4 kB 00:00 updates/primary_db | 181 kB 00:00 Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package kernel-lt.x86_64 0:3.10.59-1.el6.elrepo will be installed --> Finished Dependency Resolution Dependencies Resolved ===================================================================================================================================================== Package Arch Version Repository Size ===================================================================================================================================================== Installing: kernel-lt x86_64 3.10.59-1.el6.elrepo elrepo-kernel 33 M Transaction Summary ===================================================================================================================================================== Install 1 Package(s) Total download size: 33 M Installed size: 153 M Downloading Packages: kernel-lt-3.10.59-1.el6.elrepo.x86_64.rpm | 33 MB 28:58 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Warning: RPMDB altered outside of yum. Installing : kernel-lt-3.10.59-1.el6.elrepo.x86_64 1/1 Verifying : kernel-lt-3.10.59-1.el6.elrepo.x86_64 1/1 Installed: kernel-lt.x86_64 0:3.10.59-1.el6.elrepo Complete! vi /etc/grub.conf 修改默认的启动内核，新安装的内核一般在第一个，这里把default = 1 改为 default = 0 就好了。default=1 timeout=5 splashimage=(hd0,0)/boot/grub/splash.xpm.gz hiddenmenu title CentOS (3.10.59-1.el6.elrepo.x86_64) root (hd0,0) kernel /boot/vmlinuz-3.10.59-1.el6.elrepo.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet initrd /boot/initramfs-3.10.59-1.el6.elrepo.x86_64.img title CentOS (2.6.32-431.23.3.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-431.23.3.el6.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet initrd /boot/initramfs-2.6.32-431.23.3.el6.x86_64.img ~ 重启云主机，查看内核是否升级成功。# uname -a Linux xxxxxxx 3.10.59-1.el6.elrepo.x86_64 #1 SMP Thu Oct 30 23:46:31 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux

安装 Docker

安装软件源，安装 Docker 软件。# yum install http://mirrors.yun-idc.com/epel/6/i386/epel-release-6-8.noarch.rpm # yum install docker-io

启动 Docker

安装平常的方法启动 Docker 之后，发现仍然提示有问题。# service docker start Starting cgconfig service: [ OK ] Starting docker: [ OK ] # docker version Client version: 1.2.0 Client API version: 1.14 Go version (client): go1.3.3 Git commit (client): fa7b24f/1.2.0 OS/Arch (client): linux/amd64 2014/11/05 21:03:08 Cannot connect to the Docker daemon. Is 'docker -d' running on this host? 使用 docker -d 来查看详细的启动过程。# docker -d 2014/11/05 21:10:56 docker daemon: 1.2.0 fa7b24f/1.2.0; execdriver: native; graphdriver: [40a2dcc2] +job serveapi(unix:///var/run/docker.sock) [info] Listening for HTTP on unix (/var/run/docker.sock) [40a2dcc2] +job init_networkdriver() [40a2dcc2.init_networkdriver()] creating new bridge for docker0 Could not find a free IP address range for interface 'docker0'. Please configure its address manually and run 'docker -b docker0' [40a2dcc2] -job init_networkdriver() = ERR (1) 2014/11/05 21:10:56 Could not find a free IP address range for interface 'docker0'. Please configure its address manually and run 'docker -b docker0' 提示我们没有空余 ip 分配给 docker0 了。那我们就使用 --bip 参数来手工分配给 ip 地址。比如：# docker --bip=192.168.100.1/24 -d & [2] 2388 [root@iZ23pznlje4Z ~]# 2014/11/05 21:16:55 docker daemon: 1.2.0 fa7b24f/1.2.0; execdriver: native; graphdriver: [dc6906e7] +job serveapi(unix:///var/run/docker.sock) [info] Listening for HTTP on unix (/var/run/docker.sock) [dc6906e7] +job init_networkdriver() [dc6906e7] -job init_networkdriver() = OK (0) 2014/11/05 21:16:55 WARNING: Your kernel does not support cgroup swap limit. [info] Loading containers: [info] : done. [dc6906e7] +job acceptconnections() [dc6906e7] -job acceptconnections() = OK (0) 这里提示警告 Your kernel does not support cgroup swap limit.，我们可以使用 lxc-checkconfig 来检查。# lxc-checkconfig Kernel configuration not found at /proc/config.gz; searching... Kernel configuration found at /boot/config-3.10.59-1.el6.elrepo.x86_64 --- Namespaces --- Namespaces: enabled Utsname namespace: enabled Ipc namespace: enabled Pid namespace: enabled User namespace: missing Network namespace: enabled Multiple /dev/pts instances: enabled --- Control groups --- Cgroup: enabled Cgroup clone_children flag: enabled Cgroup device: enabled Cgroup sched: enabled Cgroup cpu account: enabled Cgroup memory controller: enabled Cgroup cpuset: enabled --- Misc --- Veth pair device: enabled Macvlan: enabled Vlan: enabled File capabilities: enabled Note : Before booting a new kernel, you can check its configuration usage : CONFIG=/path/to/config /usr/bin/lxc-checkconfig 可以看到 Control groups 项目都是支持的，所以我们暂时忽略这个告警。

测试使用

由于 Aliyun 的网络直接 pull 官方镜像也不是很稳定，这里推荐使用Dockerpool 官方网站的标准ubuntu镜像来测试。下载镜像，重新标记镜像。# docker pull dl.dockerpool.com:5000/ubuntu:14.04 # docker images REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE dl.dockerpool.com:5000/ubuntu latest 5506de2b643b 12 days ago 197.8 MB # docker tag 550 ubuntu # docker rmi dl.dockerpool.com:5000/ubuntu [dc6906e7] +job image_delete(dl.dockerpool.com:5000/ubuntu) [dc6906e7] +job log(untag, 5506de2b643be1e6febbf3b8a240760c6843244c41e12aa2f60ccbb7153d17f5, ) [dc6906e7] -job log(untag, 5506de2b643be1e6febbf3b8a240760c6843244c41e12aa2f60ccbb7153d17f5, ) = OK (0) [dc6906e7] -job image_delete(dl.dockerpool.com:5000/ubuntu) = OK (0) Untagged: dl.dockerpool.com:5000/ubuntu:latest 启动容器，并测试网络。# docker run -ti ubuntu root@66ff9a55a4f5:/# ping www.dockerpool.com PING www.dockerpool.com (xxx.xxx.xxx.xxx) 56(84) bytes of data. ^C64 bytes from 203.195.193.251: icmp_seq=1 ttl=47 time=31.4 ms