第四篇 K8S集群部署之Flannel网络插件安装

一 版本说明

• flannel : v0.11.0
• etcd集群: 沿用上一章节的集群 v3.4.3

二 在node安装docker

先在node上安装docker
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo
yum install docker-ce -y
curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s http://bc437cce.m.daocloud.io
systemctl start docker
systemctl enable docker

二 etcd设置子网网段

# 设置环境变量 从etcd3.4之后 默认etcdctl的api版本是3 所以需要通过环境变量改变
export ETCDCTL_API=2

/opt/etcd/bin/etcdctl \
--ca-file=/opt/etcd/ssl/ca.pem \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--endpoints="https://192.168.0.201:2379,https://192.168.0.211:2379,https://192.168.0.212:2379" \
set /k8s/network/config '{"Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

三 下载并安装flannel

wget https://github.com/coreos/flannel/releases/download/v0.11.0/flannel-v0.11.0-linux-amd64.tar.gz
tar -zxvf flannel-v0.11.0-linux-amd64.tar.gz

mkdir -p /opt/kubernetes/bin
mv flanneld mk-docker-opts.sh /opt/kubernetes/bin
mkdir -p /opt/kubernetes/cfg

cat << EOF | tee /opt/kubernetes/cfg/flanneld
# etcd url location. Point this to the server where etcd runs
FLANNELD_ETCD_ENDPOINTS="https://192.168.0.201:2379,https://192.168.0.211:2379,https://192.168.0.212:2379"

# etcd config key. This is the configuration key that flannel queries
# For address range assignment
FLANNELD_ETCD_PREFIX="/k8s/network"

# Any additional options that you want to pass
FLANNELD_ETCD_CAFILE="/opt/etcd/ssl/ca.pem"
FLANNELD_ETCD_CERTFILE="/opt/etcd/ssl/server.pem"
FLANNELD_ETCD_KEYFILE="/opt/etcd/ssl/server-key.pem"
FLANNEL_OPTIONS=""
EOF

# systemd管理Flannel：
# cat << EOF | tee /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 
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

# 配置Docker启动指定子网段：
cat << EOF | tee /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/run/flannel/subnet.env
ExecStart=/usr/bin/dockerd \$DOCKER_NETWORK_OPTIONS
ExecReload=/bin/kill -s HUP \$MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target
EOF

# 重启flannel和docker：
systemctl daemon-reload
systemctl start flanneld
systemctl enable flanneld
systemctl restart docker

四 检查是否生效

确保flannel.1与docker0在同一网段，在另一台机器ping 172.17.97.1能ping通

ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:cd:68:2a brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.211/24 brd 192.168.0.255 scope global noprefixroute ens3
       valid_lft forever preferred_lft forever
    inet6 fe80::f62:962d:1386:352/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default 
    link/ether 42:1b:0c:33:56:de brd ff:ff:ff:ff:ff:ff
    inet 172.17.97.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
    inet6 fe80::401b:cff:fe33:56de/64 scope link 
       valid_lft forever preferred_lft forever
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:4a:1f:8a:bb brd ff:ff:ff:ff:ff:ff
    inet 172.17.97.1/24 brd 172.17.97.255 scope global docker0
       valid_lft forever preferred_lft forever