docker是POD基本运行环境，kubernetes默认以dockerd作为runtime运行引擎，在安装docker-ce前必须先升级内核到最新lts版，这是因为为了让docker-ce支持数据存储类型overlay2，这里将会以二进制文件方式部署在所有的worker节点上部署docker-ce。

1. 准备工作

#################### Variable parameter setting ######################
DOCKER_INSTALL_PATH=/data/apps/k8s/docker
SOFTWARE=/root/software
VERSION=18.09.6
PACKAGE=docker-${VERSION}.tgz
DOWNLOAD_URL=https://download.docker.com/linux/static/stable/x86_64/$PACKAGE
MIRRORS1=https://docker.mirrors.ustc.edu.cn
MIRRORS2=https://registry-mirrors.mo9.com
USER=docker

2. 安装docker

准备docker-ce安装环境

# 1.Uninstall the original docker installation package
sudo yum -y remove docker docker-client \
  docker-client-latest  docker-common docker-latest \
  docker-latest-logrotate docker-selinux docker-engine-selinux docker-engine 
### 2 Setting firewall rules for docker
/sbin/iptables -P FORWARD ACCEPT
sudo sed -i '/iptables -P FORWARD ACCEPT/d' /etc/rc.local
echo -e "/sbin/iptables -P FORWARD ACCEPT"  >> /etc/rc.local

### 3.Install docker-ce package with yum.
sudo yum install -y yum-utils device-mapper-persistent-data lvm2 bridge-utils 
sudo yum-config-manager \
  --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

创建docker安装相关安装目录以及dockers用户组

### 4.Install docker-ce package with source.
# Check if the install directory exists and Check if the docker group exists .
if [ ! -d $DOCKER_INSTALL_PATH/bin ]; then
     mkdir -p $DOCKER_INSTALL_PATH/bin
fi

egrep "^$USER" /etc/group-
if [ $? -ne 0 ]; then
     groupadd $USER
fi

### 5.Download source package of docker-ce
if [ ! -f "$SOFTWARE/docker-${VERSION}.tgz" ]; then
     wget $DOWNLOAD_URL -P $SOFTWARE >>/dev/null 2>&1
fi
cd $SOFTWARE && tar -zxf $SOFTWARE/docker-${VERSION}.tgz -C ./
sudo cp -fp $SOFTWARE/docker/* $DOCKER_INSTALL_PATH/bin
cd $DOCKER_INSTALL_PATH/bin/
ln -sf docker,dockerd,containerd,containerd-shim,runc,ctr /usr/local/bin

### 6.Create daemon.json file for docker
# Create daemon.json file  path
if [ ! -d "/etc/docker" ]; then
     mkdir /etc/docker/
fi

• docker默认以root用户运行，为了安全起见，方便其他用户调用docker api，需要创建一个docker组用户

创建docker配置文件

cat >/etc/docker/daemon.json <

cat >/usr/lib/systemd/system/docker.service <<"EOF"
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
EnvironmentFile=-/run/flannel/docker
ExecStart=/usr/local/bin/dockerd  $DOCKER_NETWORK_OPTIONS
ExecReload=/bin/kill -s HUP $MAINPID
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
# Uncomment TasksMax if your systemd version supports it.
# Only systemd 226 and above support this version.
#TasksMax=infinity
TimeoutStartSec=0
# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes
# kill only the docker process, not all processes in the cgroup
KillMode=process
# restart the docker process if it exits prematurely
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
[Install]
WantedBy=multi-user.target
EOF

service dokcker start

sudo journal -u docker