docker结合flannel网络

Etcd安装

生产环境建议使用集群方式

wget https://github.com/etcd-io/etcd/releases/download/v3.3.15/etcd-v3.3.15-linux-amd64.tar.gz
tar -zxvf etcd-v3.3.15-linux-amd64.tar.gz && cd etcd-v3.3.15-linux-amd64
mv etcd* /usr/local/bin/
mkdir /var/lib/etcd/

cat /usr/lib/systemd/system/etcd.service 
[Unit]
Description=Etcd Server
After=netNork.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
ExecStart=/usr/local/bin/etcd \
--name=etcd \
--data-dir=/var/lib/etcd/default.etcd \
--listen-peer-urls=http://192.168.3.155:2380 \
--listen-client-urls=http://192.168.3.155:2379,http://127.0.0.1:2379 \
--advertise-client-urls=http://192.168.3.155:2379 \
--initial-advertise-peer-urls=http://192.168.3.155:2380 \
--initial-cluster=etcd=http://192.168.3.155:2380 \
--initial-cluster-token=etcd-cluster \
--initial-cluster-state=new
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target

systemctl start etcd

安装flannel

yum -y install flannel

cat /etc/sysconfig/flanneld

FLANNEL_ETCD_ENDPOINTS="http://192.168.3.155:2379"

FLANNEL_ETCD_PREFIX="/atomic.io/network"

注册flannel的网络配置到etcd

3.3.15版本默认api为V3，flannel支持V2版本

ETCDCTL_API=2 etcdctl --endpoint=http://192.168.3.155:2379 set /atomic.io/network/config '{"Network":"172.17.0.0/16", "SubnetMin": "172.17.1.0", "SubnetMax": "172.17.254.0", "Backend": {"Type": "vxlan"}}'

systemctl start flannel

Flannel启动后，将从etcd获取网络配置信息

划分子网并在etcd中注册

将网络配置写入/run/flannel/subnet.env，并通过脚本生成/run/flannel/docker文件

查看etcd注册信息

修改docker启动参数

cat /usr/lib/systemd/system/docker.service

EnvironmentFile=/var/run/flannel/docker

ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS

systemctl daemon-reload && systemctl restart docker

查看IP

参考：

https://coreos.com/flannel/docs/latest/running.html#docker-integration

https://coreos.com/flannel/docs/latest/flannel-config.html

https://github.com/etcd-io/etcd