使用外部etcd集群初始化k8s

Postkarte不想说话
831 阅读4分钟

创建etcd集群

下载用于生成证书的工具

# 下载工具
wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64 
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
# 将工具移动到指定目录
mv cfssl_linux-amd64 /usr/bin/cfssl 
mv cfssljson_linux-amd64 /usr/bin/cfssljson
# 将工具加上可执行权限
chmod +x /usr/bin/cfssl 
chmod +x /usr/bin/cfssljson

生成ca证书

自签证书颁发机构（CA）

ca配置文件
# 创建一个目录
mkdir -p ~/etcd_tls
# 切换到该目录
cd ~/etcd_tls
# 生成ca配置文件
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
ca证书请求文件
cat > ca-csr.json << EOF
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}
EOF
生成 ca 证书 (ca.pem 和 ca-key.pem 文件)
cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

使用上面创建的自签CA签发Etcd HTTPS证书

创建证书申请文件
# 创建证书申请文件：
cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "172.16.16.180",
    "172.16.16.181",
    "172.16.16.182"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF
# 注：上述文件hosts字段中IP为所有etcd节点的集群内部通信IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。
生成证书 (server.pem 和 server-key.pem)
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

创建etcd集群所使用的的目录

mkdir /opt/etcd/{bin,cfg,ssl} -p

将前面生成的证书拷贝到目录

cp ~/etcd_tls/ca*pem ~/etcd_tls/server*pem /opt/etcd/ssl/

开始安装etcd

下载etcd

# 创建一个用于保存下载软件的目录
mkdir ~/software
cd ~/software
# 下载etcd包
wget https://github.com/etcd-io/etcd/releases/download/v3.5.8/etcd-v3.5.8-linux-amd64.tar.gz
# 解压etcd包
tar -xf etcd-v3.5.8-linux-amd64.tar.gz 
# 将etcd相关程序拷贝到前面创建的目录
mv etcd-v3.5.8-linux-amd64/{etcd,etcdctl} /opt/etcd/bin

创建etcd配置文件

cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.16.16.180:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.16.16.180:2379"

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.16.16.180:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.16.16.180:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://172.16.16.180:2380,etcd-2=https://172.16.16.181:2380,etcd-3=https://172.16.16.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster-cvc-cvcv-ty"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

# 参数说明
ETCD_NAME : 节点名称，集群中唯一
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

创建systemd服务文件管理etcd启动停止

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

[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd --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 --logger=zap
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target
EOF

把配置拷贝到其他 etcd 节点

scp -r /opt/etcd/ root@172.16.16.181:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.16.16.181:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@172.16.16.182:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.16.16.182:/usr/lib/systemd/system/

启动etcd

systemctl daemon-reload 
systemctl start etcd 
systemctl enable etcd

其他两个节点参数修改

vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-1" # 修改此处，节点2改为etcd-2，节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.16.16.180:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://172.16.16.180:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.16.16.180:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://172.16.16.180:2379"       # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://172.16.16.180:2380,etcd-2=https://172.16.16.181:2380,etcd-3=https://172.16.16.182:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

# 启动 etcd 
systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

部署etcd时候可能会出现的问题

问题一

# 因为是云服务器环境，所以说如果按着上面的etcd配置文件来配置的话会导致节点不通的情况
[root@master ~]# tcpdump -i eth0 -s0 -nnn port 2379
dropped privs to tcpdump
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
08:51:08.245269 IP 39.86.24.130.42548 > 10.120.98.121.2379: Flags [S], seq 3202545622, win 64240, options [mss 1410,sackOK,TS val 850462034 ecr 0,nop,wscale 8], length 0
08:51:08.245284 IP 10.120.98.121.2379 > 39.86.24.130.42548: Flags [R.], seq 0, ack 3202545623, win 0, length 0

image.png

如上图所述，etcd监听在公网ip上，但是客户端请求时候由于云服务器环境会进行nat转换，导致etcd不会接受数据

解决办法
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://0.0.0.0:2380"  # 将etcd监听的地址改为0.0.0.0即可
ETCD_LISTEN_CLIENT_URLS="https://0.0.0.0:2379" # 将etcd监听的地址改为0.0.0.0即可

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.16.0.3:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.16.0.3:2379" 
ETCD_INITIAL_CLUSTER="etcd-1=https://172.16.0.3:2380,etcd-2=https://172.16.0.4:2380,etcd-3=https://172.16.0.5:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster-yyt78888-rterdg"
ETCD_INITIAL_CLUSTER_STATE="new"

测试etcd集群是否健康

[root@master ~]# ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://172.16.0.3:2379,https://172.16.0.4:2379,https://172.16.0.5:2379" endpoint health --write-out=table
+------------------------------+--------+--------------+-------+
|           ENDPOINT           | HEALTH |     TOOK     | ERROR |
+------------------------------+--------+--------------+-------+
| https://172.16.0.3:2379 |   true |  10.459873ms |       |
| https://172.16.0.4:2379 |   true |  23.587933ms |       |
|  https://172.16.0.5:2379 |   true | 355.103131ms |       |
+------------------------------+--------+--------------+-------+

开始部署k8s

k8s初始化配置文件

apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 172.16.0.3  # 这里需要改为公网ip
  bindPort: 6443
nodeRegistration:
  criSocket: unix:///run/containerd/containerd.sock
  imagePullPolicy: IfNotPresent
  name: master  # master节点的主机名
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  external:
     endpoints:
        - https://172.16.0.3:2379  # 这里需要改为自己部署的etcd集群的地址
        - https://172.16.0.4:2379
        - https://172.16.0.5:2379
     caFile: /opt/etcd/ssl/ca.pem  # 认证密钥文件
     certFile: /opt/etcd/ssl/server.pem
     keyFile: /opt/etcd/ssl/server-key.pem
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: 1.27.0
controlPlaneEndpoint: 172.16.0.3:6443  # 注意这里要加上，要不然后面添加第二个master时候会有报错提示
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
  podSubnet: 10.244.0.0/16 #pod的网段地址配置
scheduler: {}
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs   # 配置使kubeproxy使用ipvs模式转发流量

初始化

[root@master ~]# kubeadm init --config kube-config.yaml

产生如下输出


To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.16.0.3:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:7919df493c3jkk9fe545a70c6e3c1d9iooi

按照上面的提示执行命令

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

# 可以看到控制层面创建成功
[root@master ~]# kubectl  get node
NAME     STATUS   ROLES           AGE    VERSION
master   Ready    control-plane   8m7s   v1.27.1

# 加入工作节点
在工作节点执行命令
kubeadm join 172.16.0.3:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:7919df493c3jkk9fe545a70c6e3c1d9iooi

添加第二个控制层面

# 执行命令
[root@master ~]# kubeadm init phase upload-certs --upload-certs
[upload-certs] Storing the certificates in Secret "kubeadm-certs" in the "kube-system" Namespace
[upload-certs] Using certificate key:
57e92e1c0039191f73898984c78cfe5f6f487bd4d8624454f3a850f4a1sh

# 执行命令
[root@master ~]# kubeadm token create --print-join-command
kubeadm join 172.16.0.3:6443 --token qk5fng.khu1iwra4eccvc62 --discovery-token-ca-cert-hash sha256:7919df493c373bae9e0yuyu70c6e3c1d931dcc2ed756ae 

# 将上面得到的两个拼接
kubeadm join 172.16.0.3:6443 --token qk5fng.khu1iwra4eccvc62 --discovery-token-ca-cert-hash sha256:7919df493c373bae9e0yuyu70c6e3c1d931dcc2ed756ae  --control-plane --certificate-key  57e92e1c0039191f73898984c78cfe5f6f487bd4d8624454f3a850f4a1sh
# 注意：要加上--control-plane --certificate-key ，不然就会添加为node节点而不是master

执行添加命令时候会有如下输出

[root@master2 ~]# kubeadm join 172.16.0.3:6443 --token qk5fng.khu1iwra4eccvc62 --discovery-token-ca-cert-hash sha256:7919df493c373bae9e0yuyu70c6e3c1d931dcc2ed756ae  --control-plane --certificate-key  57e92e1c0039191f73898984c78cfe5f6f487bd4d8624454f3a850f4a1sh
[preflight] Running pre-flight checks
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
error execution phase preflight: 
One or more conditions for hosting a new control plane instance is not satisfied.

unable to add a new control plane instance to a cluster that doesn't have a stable controlPlaneEndpoint address

Please ensure that:
* The cluster has a stable controlPlaneEndpoint address.
* The certificates that must be shared among control plane instances are provided.


To see the stack trace of this error execute with --v=5 or higher
解决办法
修改master的endpoint地址
kubectl edit cm kubeadm-config -n kube-system

修改结果如下

image.png 修改完后再次在第二个master上执行初始化命令

# 显示如下报错，缺少etcd的证书文件
error execution phase control-plane-prepare/download-certs: error downloading certs: the Secret does not include the required certificate or key - name: external-etcd-ca.crt, path: /opt/etcd/ssl/ca.pem
To see the stack trace of this error execute with --v=5 or higher
# 因为是使用的外部etcd所以要使用如下命令生成token
kubeadm init phase upload-certs --upload-certs --config kube-config.yaml

再次执行添加master后成功

* Certificate signing request was sent to apiserver and approval was received.
* The Kubelet was informed of the new secure connection details.
* Control plane label and taint were applied to the new node.
* The Kubernetes control plane instances scaled up.


To start administering your cluster from this node, you need to run the following as a regular user:

        mkdir -p $HOME/.kube
        sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
        sudo chown $(id -u):$(id -g) $HOME/.kube/config

Run 'kubectl get nodes' to see this node join the cluster.

image.png

参考链接

avatar
文章
阅读
粉丝