1、環境準備

共需要3臺虛擬機
1臺作為master
2臺作為node節點

2、docker引擎部署

所有node節點部署docker引擎
詳見docker安裝腳本

Docker的（理論+安裝）
Docker鏡像加速

這是在node節點上必須配置的

3、flannel網路配置

Overlay Network:覆寫網路，在基礎網路上疊加的一種虛擬網路技術模式，該網路中的主機通過虛擬鏈路連接起來，
VXLAN:將源資料包封裝到UDP中，并使用基礎網路的IP/MAC作為外層報文頭進行封裝，然后在以太網上傳輸，到達目的地后由隧道端點解封裝并將資料發送給目
標地址，
Flannel:是Overlay網路的一 種， 也是將源資料包封裝在另一種網路 包里面進行路由轉發和通信，目前已經支持UDP、VXLAN、 AWS VPC和GCE路由等資料轉發方
式，

配置的時候要將這幅圖看一下

3.1、寫入分配的子網段到ETCD中，供flannel使用

master操作

[root@localhost etcd-cert]# /opt/etcd/bin/etcdctl --ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem --endpoints="https://192.168.162.10:2379,https://192.168.162.30:2379,https://192.168.162.40:2379" set /coreos.com/network/config '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}

3.2、查看寫入的資訊

[root@localhost etcd-cert]# /opt/etcd/bin/etcdctl --ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem --endpoints="https://192.168.162.10:2379,https://192.168.162.30:2379,https://192.168.162.40:2379" get /coreos.com/network/config
{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}

3.3、拷貝到所有node節點（只需要部署在node節點即可）

[root@localhost k8s]# scp flannel-v0.10.0-linux-amd64.tar.gz root@192.168.162.30:/root
[root@localhost k8s]# scp flannel-v0.10.0-linux-amd64.tar.gz root@192.168.162.40:/root

3.4、所有node節點操作解壓

[root@localhost ~]# tar zxvf flannel-v0.10.0-linux-amd64.tar.gz 
flanneld
mk-docker-opts.sh
README.md
//k8s作業目錄
[root@localhost ~]# mkdir /opt/kubernetes/{cfg,bin,ssl} -p
[root@localhost ~]# mv mk-docker-opts.sh flanneld /opt/kubernetes/bin/




[root@localhost ~]# vim flannel.sh
#!/bin/bash

ETCD_ENDPOINTS=${1:-"http://127.0.0.1:2379"}

cat <<EOF >/opt/kubernetes/cfg/flanneld

FLANNEL_OPTIONS="--etcd-endpoints=${ETCD_ENDPOINTS} \
-etcd-cafile=/opt/etcd/ssl/ca.pem \
-etcd-certfile=/opt/etcd/ssl/server.pem \
-etcd-keyfile=/opt/etcd/ssl/server-key.pem"

EOF

cat <<EOF >/usr/lib/systemd/system/flanneld.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network-online.target network.target
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/opt/kubernetes/cfg/flanneld
ExecStart=/opt/kubernetes/bin/flanneld --ip-masq \$FLANNEL_OPTIONS
ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/subnet.env
Restart=on-failure

[Install]
WantedBy=multi-user.target

EOF

systemctl daemon-reload
systemctl enable flanneld
systemctl restart flanneld

3.5、開啟flannel網路功能

[root@localhost ~]# bash flannel.sh https://192.168.162.10:2379,https://192.168.162.30:2379,https://192.168.162.40:2379

Created symlink from /etc/systemd/system/multi-user.target.wants/flanneld.service to /usr/lib/systemd/system/flanneld.service.

3.6、配置docker連接flannel

看好這個格式，不要自己需改，就按照下面的配置就行
[root@localhost ~]# vim /usr/lib/systemd/system/docker.service

[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/subnet.env
ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always



[root@localhost ~]# cat /run/flannel/subnet.env
DOCKER_OPT_BIP="--bip=172.17.42.1/24"
DOCKER_OPT_IPMASQ="--ip-masq=false"
DOCKER_OPT_MTU="--mtu=1450"
//說明：bip指定啟動時的子網
DOCKER_NETWORK_OPTIONS=" --bip=172.17.42.1/24 --ip-masq=false --mtu=1450" 

3.7、重啟docker服務

[root@localhost ~]# systemctl daemon-reload
[root@localhost ~]# systemctl restart docker

3.8、查看flannel網路

[root@localhost ~]# ifconfig

測驗ping通對方docker0網卡 證明flannel起到路由作用

[root@localhost ~]# docker run -it centos:7 /bin/bash

[root@5f9a65565b53 /]# yum install net-tools -y


[root@3f7ae4f27c85 /]# ifconfig 
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1450
        inet 172.17.84.2  netmask 255.255.255.0  broadcast 172.17.84.255
        ether 02:42:ac:11:54:02  txqueuelen 0  (Ethernet)
        RX packets 20172  bytes 15438714 (14.7 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 9838  bytes 534863 (522.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

再次測驗ping通兩個node中的centos:7容器