kubernetes.Etcd集群构建和flannel网络部署

第五节.部署Etcd

二进制包下载地址：https://github.com/coreos/etcd/releases/tag/v3.2.12

以下部署步骤在规划的三个etcd节点操作一样，唯一不同的是etcd配置文件中的服务器IP要写当前的：
解压二进制包：

# mkdir /opt/etcd/{bin,cfg,ssl} -p
# tar zxvf etcd-v3.2.12-linux-amd64.tar.gz
# mv etcd-v3.2.12-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

创建etcd配置文件：

# cat /opt/etcd/cfg/etcd   
#[Member]
ETCD_NAME="etcd01"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.31.63:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.31.63:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.31.63:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.31.63:2379"
ETCD_INITIAL_CLUSTER="etcd01=https://192.168.31.63:2380,etcd02=https://192.168.31.65:2380,etcd03=https://192.168.31.66:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

• ETCD_NAME 节点名称
• ETCD_DATA_DIR 数据目录
• ETCD_LISTEN_PEER_URLS 集群通信监听地址
• ETCD_LISTEN_CLIENT_URLS 客户端访问监听地址
• ETCD_INITIAL_ADVERTISE_PEER_URLS 集群通告地址
• ETCD_ADVERTISE_CLIENT_URLS 客户端通告地址
• ETCD_INITIAL_CLUSTER 集群节点地址
• ETCD_INITIAL_CLUSTER_TOKEN 集群Token
• ETCD_INITIAL_CLUSTER_STATE 加入集群的当前状态，new是新集群，existing表示加入已有集群

systemd管理etcd：

# cat /usr/lib/systemd/system/etcd.service 
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd
ExecStart=/opt/etcd/bin/etcd \
--name=${ETCD_NAME} \
--data-dir=${ETCD_DATA_DIR} \
--listen-peer-urls=${ETCD_LISTEN_PEER_URLS} \
--listen-client-urls=${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 \
--advertise-client-urls=${ETCD_ADVERTISE_CLIENT_URLS} \
--initial-advertise-peer-urls=${ETCD_INITIAL_ADVERTISE_PEER_URLS} \
--initial-cluster=${ETCD_INITIAL_CLUSTER} \
--initial-cluster-token=${ETCD_INITIAL_CLUSTER_TOKEN} \
--initial-cluster-state=new \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

把刚才生成的证书拷贝到配置文件中的位置：

# cp ca*pem server*pem /opt/etcd/ssl

启动并设置开启启动：

# systemctl start etcd
# systemctl enable etcd

都部署完成后，检查etcd集群状态：

# /opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379" \
cluster-health
member 18218cfabd4e0dea is healthy: got healthy result from https://192.168.31.63:2379
member 541c1c40994c939b is healthy: got healthy result from https://192.168.31.65:2379
member a342ea2798d20705 is healthy: got healthy result from https://192.168.31.66:2379
cluster is healthy

如果输出上面信息，就说明集群部署成功。如果有问题第一步先看日志：/var/log/message 或 journalctl -u etcd

部署Flannel网络

工作原理：

图片.png

Falnnel要用etcd存储自身一个子网信息，所以要保证能成功连接Etcd，写入预定义子网段：

# /opt/etcd/bin/etcdctl \
--ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem \
--endpoints="https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379" \
set /coreos.com/network/config  '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

• 网络类型指定vxlan

以下部署步骤在规划的每个node节点都操作。

下载二进制包：

# wget https://github.com/coreos/flannel/releases/download/v0.10.0/flannel-v0.10.0-linux-amd64.tar.gz
# tar zxvf flannel-v0.9.1-linux-amd64.tar.gz
# mv flanneld mk-docker-opts.sh /opt/kubernetes/bin

配置Flannel：

# cat /opt/kubernetes/cfg/flanneld
FLANNEL_OPTIONS="--etcd-endpoints=https://192.168.31.63:2379,https://192.168.31.65:2379,https://192.168.31.66:2379 -etcd-cafile=/opt/etcd/ssl/ca.pem -etcd-certfile=/opt/etcd/ssl/server.pem -etcd-keyfile=/opt/etcd/ssl/server-key.pem"

systemd管理Flannel：

# cat /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

配置Docker启动指定子网段：

# cat /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

重启flannel和docker：

# systemctl daemon-reload
# systemctl start flanneld
# systemctl enable flanneld
# systemctl restart docker

检查flannel网络是否生效：

# ps -ef |grep docker
root     20941     1  1 Jun28 ?        09:15:34 /usr/bin/dockerd --bip=172.17.34.1/24 --ip-masq=false --mtu=1450
# ip addr
3607: flannel.1:  mtu 1450 qdisc noqueue state UNKNOWN 
    link/ether 8a:2e:3d:09:dd:82 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
3608: docker0:  mtu 1450 qdisc noqueue state UP 
    link/ether 02:42:31:8f:d3:02 brd ff:ff:ff:ff:ff:ff
    inet 172.17.34.1/24 brd 172.17.34.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:31ff:fe8f:d302/64 scope link 
       valid_lft forever preferred_lft forever

确保docker0与flannel.1在同一网段。
测试不同节点互通，在当前节点访问另一个Node节点docker0 IP：

# ping 172.17.58.1
PING 172.17.58.1 (172.17.58.1) 56(84) bytes of data.
64 bytes from 172.17.58.1: icmp_seq=1 ttl=64 time=0.263 ms
64 bytes from 172.17.58.1: icmp_seq=2 ttl=64 time=0.204 ms
如果能通说明Flannel部署成功。如果不通检查下日志：journalctl -u flannel