1.为Flannel生成证书:
[root@k8s-master ~]# cd /usr/local/src/ssl/ [root@k8s-master ssl]# cat > flanneld-csr.json <<EOF { "CN": "flanneld", "hosts": [], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "ST": "BeiJing", "L": "BeiJing", "O": "k8s", "OU": "System" } ] } EOF
2.生成证书
[root@k8s-master ssl]# cfssl gencert -ca=/opt/kubernetes/ssl/ca.pem \ -ca-key=/opt/kubernetes/ssl/ca-key.pem \ -config=/opt/kubernetes/ssl/ca-config.json \ -profile=kubernetes flanneld-csr.json | cfssljson -bare flanneld
3.分发证书文件
[root@k8s-master ssl]# cp flanneld*.pem /opt/kubernetes/ssl/ [root@k8s-master ssl]# scp flanneld*.pem 10.200.3.106:/opt/kubernetes/ssl/ [root@k8s-master ssl]# scp flanneld*.pem 10.200.3.107:/opt/kubernetes/ssl/
4.下载Flannel软件包
[root@k8s-master ssl]# cd /usr/local/src [root@k8s-master src]# wget \ https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz [root@k8s-master src]# tar zxf flannel-v0.10.0-linux-amd64.tar.gz [root@k8s-master src]# cp flanneld mk-docker-opts.sh /opt/kubernetes/bin/
分发文件到node节点
[root@k8s-master src]# scp flanneld mk-docker-opts.sh 10.200.3.106:/opt/kubernetes/bin/ [root@k8s-master src]# scp flanneld mk-docker-opts.sh 10.200.3.107:/opt/kubernetes/bin/
分发对应脚本到/opt/kubernetes/bin目录下
[root@k8s-master src]# cd /usr/local/src/kubernetes/cluster/centos/node/bin/ [root@k8s-master bin]# cp remove-docker0.sh /opt/kubernetes/bin/ [root@k8s-master bin]# scp remove-docker0.sh 10.200.3.106:/opt/kubernetes/bin/ remove-docker0.sh 100% 850 0.8KB/s 00:00 [root@k8s-master bin]# scp remove-docker0.sh 10.200.3.107:/opt/kubernetes/bin/ remove-docker0.sh 100% 850 0.8KB/s 00:00 [root@k8s-master bin]#
5.配置Flannel
[root@k8s-master ~]# cat > /opt/kubernetes/cfg/flannel <<EOF FLANNEL_ETCD="-etcd-endpoints=https://10.200.3.105:2379,https://10.200.3.106:2379,https://10.200.3.107:2379" FLANNEL_ETCD_KEY="-etcd-prefix=/kubernetes/network" FLANNEL_ETCD_CAFILE="--etcd-cafile=/opt/kubernetes/ssl/ca.pem" FLANNEL_ETCD_CERTFILE="--etcd-certfile=/opt/kubernetes/ssl/flanneld.pem" FLANNEL_ETCD_KEYFILE="--etcd-keyfile=/opt/kubernetes/ssl/flanneld-key.pem" EOF
分发配置到其它节点上
[root@k8s-master ~]# scp /opt/kubernetes/cfg/flannel 10.200.3.106:/opt/kubernetes/cfg/ [root@k8s-master ~]# scp /opt/kubernetes/cfg/flannel 10.200.3.107:/opt/kubernetes/cfg/
6.设置Flannel系统服务
[root@k8s-master ~]#vim /usr/lib/systemd/system/flannel.service [Unit] Description=Flanneld overlay address etcd agent After=network.target Before=docker.service [Service] EnvironmentFile=-/opt/kubernetes/cfg/flannel ExecStartPre=/opt/kubernetes/bin/remove-docker0.sh ExecStart=/opt/kubernetes/bin/flanneld ${FLANNEL_ETCD} ${FLANNEL_ETCD_KEY} ${FLANNEL_ETCD_CAFILE} ${FLANNEL_ETCD_CERTFILE} ${FLANNEL_ETCD_KEYFILE} ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -d /run/flannel/docker Type=notify [Install] WantedBy=multi-user.target RequiredBy=docker.service
复制系统服务脚本到其它节点上
[root@k8s-master ~]# scp /usr/lib/systemd/system/flannel.service 10.200.3.106:/usr/lib/systemd/system/ [root@k8s-master ~]# scp /usr/lib/systemd/system/flannel.service 10.200.3.107:/usr/lib/systemd/system/
7.Flannel CNI集成软件
下载CNI插件
git地址：https://github.com/containernetworking/plugins/releases
[root@k8s-master ~]# cd /usr/local/src/ [root@k8s-master src]# wget \ https://github.com/containernetworking/plugins/releases/download/v0.7.1/cni-plugins-amd64-v0.7.1.tgz
在所有节点创建该目录,存放CNI插件文件.
[root@k8s-master src]# mkdir /opt/kubernetes/bin/cni [root@k8s-master src]#tar zxf cni-plugins-amd64-v0.7.1.tgz -C /opt/kubernetes/bin/cni [root@k8s-master src]# scp -r /opt/kubernetes/bin/cni/* 10.200.3.106:/opt/kubernetes/bin/cni/ [root@k8s-master src]# scp -r /opt/kubernetes/bin/cni/* 10.200.3.107:/opt/kubernetes/bin/cni/
8.在master节点创建Etcd的key
/opt/kubernetes/bin/etcdctl --ca-file /opt/kubernetes/ssl/ca.pem --cert-file /opt/kubernetes/ssl/flanneld.pem --key-file /opt/kubernetes/ssl/flanneld-key.pem \ --no-sync -C https://10.200.3.105:2379,https://10.200.3.106:2379,https://10.200.3.107:2379 \ mk /kubernetes/network/config '{ "Network": "10.2.0.0/16", "Backend": { "Type": "vxlan", "VNI": 1 }}'
9.启动flannel
# systemctl daemon-reload # systemctl enable flannel # chmod +x /opt/kubernetes/bin/* # systemctl start flannel 查看服务状态 # systemctl status flannel
10.配置Docker使用Flannel
1.在Unit段中的After后面添加flannel.service参数，在Wants下面添加Requires=flannel.service.
2.[Service]段中Type后面添加EnvironmentFile=-/run/flannel/docker段，在ExecStart后面添加$DOCKER_OPTS参数.
配置如下：
[root@k8s-master ~]# vim /usr/lib/systemd/system/docker.service [Unit] Description=Docker Application Container Engine Documentation=https://docs.docker.com After=network-online.target firewalld.service flannel.service Wants=network-online.target Requires=flannel.service [Service] Type=notify EnvironmentFile=-/run/flannel/docker ExecStart=/usr/bin/dockerd $DOCKER_OPTS ...
将配置分发到另外两个节点中
[root@k8s-master ~]# rsync -av /usr/lib/systemd/system/docker.service 10.200.3.106:/usr/lib/systemd/system/docker.service [root@k8s-master ~]# rsync -av /usr/lib/systemd/system/docker.service 10.200.3.107:/usr/lib/systemd/system/docker.service
重启Docker服务
# systemctl daemon-reload
# systemctl restart docker
如果docker0和flannel在一个网段，则表示正常.
docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 10.2.1.1 netmask 255.255.255.0 broadcast 10.2.1.255 ether 02:42:47:f1:94:9e txqueuelen 0 (Ethernet) 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 flannel.1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1450 inet 10.2.1.0 netmask 255.255.255.255 broadcast 0.0.0.0 ether a2:5d:b6:0a:89:88 txqueuelen 0 (Ethernet) 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 1 overruns 0 carrier 0 collisions 0
至此flannel网络配置完成,k8s的集群也部署完成，下面我们来建立pod测试集群之间网络的连通性.
创建第一个K8S应用,测试集群节点是否通信
1.创建一个测试用的nginx pod.
[root@k8s-master ~]# kubectl run my-nginx --image=nginx --replicas=3 --port=80
2.查看获取IP情况
[root@k8s-master ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE nginx-service-75ccfbd5c9-f7ghk 1/1 Running 0 1d 10.2.58.179 10.20.9.222 nginx-service-75ccfbd5c9-mhw5m 1/1 Running 0 1d 10.2.49.2 10.20.9.221 nginx-service-75ccfbd5c9-sdl6q 1/1 Running 0 1d 10.2.49.3 10.20.9.221
3.测试联通性
[root@k8s-master ~]# ping 10.2.58.179 PING 10.2.58.179 (10.2.58.179) 56(84) bytes of data. 64 bytes from 10.2.58.179: icmp_seq=1 ttl=63 time=0.206 ms 64 bytes from 10.2.58.179: icmp_seq=2 ttl=63 time=0.162 ms 64 bytes from 10.2.58.179: icmp_seq=3 ttl=63 time=0.131 ms ^C --- 10.2.58.179 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.131/0.166/0.206/0.032 ms [root@k8s-master ~]# ping 10.2.49.2 PING 10.2.49.2 (10.2.49.2) 56(84) bytes of data. 64 bytes from 10.2.49.2: icmp_seq=1 ttl=63 time=0.200 ms 64 bytes from 10.2.49.2: icmp_seq=2 ttl=63 time=0.138 ms 64 bytes from 10.2.49.2: icmp_seq=3 ttl=63 time=0.145 ms ^C --- 10.2.49.2 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.138/0.161/0.200/0.027 ms [root@k8s-master ~]# ping 10.2.49.3 PING 10.2.49.3 (10.2.49.3) 56(84) bytes of data. 64 bytes from 10.2.49.3: icmp_seq=1 ttl=63 time=0.176 ms 64 bytes from 10.2.49.3: icmp_seq=2 ttl=63 time=0.125 ms 64 bytes from 10.2.49.3: icmp_seq=3 ttl=63 time=0.123 ms ^C --- 10.2.49.3 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.123/0.141/0.176/0.026 ms [root@k8s-master ~]#
4.暴露服务，创建service.
kubectl expose deployment my-nginx --port=8080 --target-port=80 --external-ip=10.20.9.221 service "my-nginx" exposed
5.查看service明细。
[root@v0-k8s-master ~]# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE my-nginx ClusterIP 10.1.159.6 10.20.9.221 8080/TCP 9s
6.测试svc访问
[root@v0-k8s-master ~]# curl -I 10.20.9.221:8080 HTTP/1.1 200 OK Server: nginx/1.15.2 Date: Tue, 31 Jul 2018 16:29:53 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Tue, 24 Jul 2018 13:02:29 GMT Connection: keep-alive ETag: "5b572365-264" Accept-Ranges: bytes
这样我们的k8s集群的部署和联通性都没问题，也算大功告成.哦也！！