CentOS Installation Docker Basics Tutorial

Upgrading CentOS

Preparatory work:

1: Install the Development Platform tool

　　　　　　yum groupinstall "Development tools"

2: Install the dependent components required for kernel upgrade

　　　　　　yum install ncurses-develqt-develhmaccalc zlib-devel binutils-devel elfutils-libelf-devel

3:因为selinux和LXC有冲突，所以需要禁用

　　　　　　# vi /etc/selinux/config SELINUX=disabled

4: 配置Fedora EPEL 源 for Yum Docker-io

# yum Install Epel-release.noarch

5: Download upgrade Linux kernel source, you can go to the official Download kernel version ( need to take Aufs module ), build it yourself. The other is to download the RPM package (http://down.51cto.com/data/1903250) with the Aufs module for direct installation ( recommended )

Upgrading the kernel (direct download RPM):

GZIP-DV kernel-ml-aufs-3.10.5-3.el6.x86_64.rpm.gz

RPM-IVH kernel-ml-aufs-3.10.5-3.el6.x86_64.rpm

　　　　

Set the new kernel as the default startup item, the newly installed kernel will be the first bit in the file list, set to 0

Vi/etc/grub.cong

Default=0

Reboot//restart

UNAME-R//detects current kernel version, 3.10.5-3.el6.x86_64, indicates upgrade kernel success

　　

Docker Installation Ideas

1: Install Docker

Yum Install Docker-io

2:要想docker正常运行还需要在/etc/fstab里增加cgroup文件系统

　　　　echo "none /sys/fs/cgroup cgroup defaults 0 0" >> /etc/fstab

　　　　mount /sys/fs/cgroup

　　　　只有重新启动才能挂载/sys/fs/cgroup（因为当前运行的内核不支持cgroup），所以上面挂载的命令也可以不执行，但系统需要重新启动

3: Detects if the Aufs module is loaded

　　　　grep aufs /proc/filesystems

4:以守护模式运行docker.io（在一个新的终端里）

Docker-d

If an exception occurs:dns/networking Errors inside the Docker,重置docker的运行环境，尝试解决问题

　　　　# pkill docker

　　　　# iptables -t nat -F

　　　　# ifconfig docker0 down

　　　　# brctl delbr docker0

　　　　# docker -d

5: Detect if Docker is working properly

Docker run Hello-world//default does not exist for this image, wait for Docker to download automatically Hello-world

A message appears indicating that the Docker installation was successful

　　　　

Hello from Docker.This message shows the your installation appears to be working correctly.To generate the This message,Docker took the following steps:1. The Docker client contacted the Docker daemon.    2. The Docker daemon pulled the "Hello-world" image from the Docker Hub. (Assuming it was notAlready locally available.) 3.The Docker Daemon created a new container from this image which runs the executable that produces the output of you a Re currently reading. 4. The Docker daemon streamed that output to the Docker client,which sent it to your terminal.To try something more ambitious, you canRunAn Ubuntu container with:$ dockerRun-it Ubuntu Bash forMore examples and ideas,visit:http:docs.docker.com/userguide/

Exception error:

1:docker when the error is started

Starting Cgconfig Service:Error:cannot Mount Cpuset to/cgroupuset:device or resource Busy, (Cgcon Fig starts by reading the configuration in/etc/cgconfig.config to create the Cgroups hierarchy, binds the desired file system and associates the subsystem, creates the Cgroups group and sets the subsystem parameters for each group)
Workaround: br>

Service Cgconfig status//check for normal operation

Vi/etc/cgconfig.conf

Mount {
Cpuset =/cgroup/cpuset;
CPU =/CGROUP/CPU;
Cpuacct =/cgroup/cpuacct;
memory =/cgroup/memory; //Comment out this paragraph, namely: #memory =/cgroup/memory;
devices =/cgroup/devices;
Freezer =/cgroup/freezer;
Net_cls =/cgroup/net_cls;
Blkio =/cgroup/blkio;
}

Service Cgconfig start//Restart Start services

2:error response from Daemon:cannot start container {ID}: [8] System ERROR:WRITE/SYS/FS/CGROUP/DOCKER/{ID}2A7CE2F9BC/CG Roup.procs:no space left on device

Processing method (refer to Address: Http://stackoverflow.com/questions/29961584/docker-cgroup-procs-no-space-left-on-device):

A Simple command should does the trick.

　　　　　　　　sudo echo 1 > /sys/fs/cgroup/docker/cgroup.clone_children

If It still does not work, run below commands and restart Docker service:

　　　　　　　　sudo echo 0 > /sys/fs/cgroup/docker/cpuset.mems　　　　　　　　sudo echo 0 > /sys/fs/cgroup/docker/cpuset.cpus

CentOS Installation Docker Basics Tutorial