Centos7环境用kubeadm搭建多节点k8s集群

1. 在每个节点上都要安装kubeadm, kubelet and kubectl, 并且docker已经运行了
2. 我这边采用的是vagrant，然后起了三台机器：

boxes = [
    {
        :name => "k8s-master",
        :eth1 => "192.168.205.120",
        :mem => "2048",
        :cpu => "2"
    },
    {
        :name => "k8s-node1",
        :eth1 => "192.168.205.121",
        :mem => "2048",
        :cpu => "1"
    },
    {
        :name => "k8s-node2",
        :eth1 => "192.168.205.122",
        :mem => "2048",
        :cpu => "1"
    }

]

3.开始安装docker环境:

yum install -y yum-utils device-mapper-persistent-data lvm2

yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

yum install -y docker

systemctl enable docker && sudo systemctl start docker

4.安装阿里云的k8s-yum源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
       http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

5.安装Kubernetes packages

setenforce 0

yum install -y kubelet kubeadm kubectl

sudo bash -c 'cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
EOF'

sudo sysctl --system
sudo systemctl stop firewalld
sudo systemctl disable firewalld
sudo swapoff -a
systemctl enable docker.service
systemctl enable kubelet.service

6.检查master节点和worker节点是否已经安装上述的程序

[[email protected] ~]# which kubeadm
/usr/bin/kubeadm
[[email protected] ~]# which kubelet
/usr/bin/kubelet
[[email protected] ~]# which kubectl
/usr/bin/kubectl
[[email protected] ~]# docker version
Client: Docker Engine - Community
 Version:           19.03.7
 API version:       1.40
 Go version:        go1.12.17
 Git commit:        7141c199a2
 Built:             Wed Mar  4 01:24:10 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.7
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.17
  Git commit:       7141c199a2
  Built:            Wed Mar  4 01:22:45 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.2.13
  GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

7.从阿里云拉取镜像

cat ./pull.sh
for i in `kubeadm config images list`; do 
  imageName=${i#k8s.gcr.io/}
  docker pull registry.aliyuncs.com/google_containers/$imageName
  docker tag registry.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
  docker rmi registry.aliyuncs.com/google_containers/$imageName
done;

8.配置Kubernetes Master node

 kubeadm init --pod-network-cidr 10.244.0.0/16 --apiserver-advertise-address 192.168.205.120

其中:–pod-network-cidr可以指定自己写的网段,apiserver-advertise-address:必须指向master节点的ip.
执行上面的命令后出现：

kubeadm join 192.168.205.120:6443 --token snipoh.vxfykjsi7e7rbtna \
    --discovery-token-ca-cert-hash sha256:e202fbfa3eed1e1d6c646dd568285947d67e99b51e824c99aeb6f45080d284c1

说明已经安装成功
9.进行一些配置

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

10.在其他节点上执行

kubeadm join 192.168.205.120:6443 --token 8b372w.suq116thqsby42a4 
    --discovery-token-ca-cert-hash sha256:3b0f82aadfdb4a3929dbd838153e38f9054f3084721a34953ec9e4069e045016

检查pod情况

kubectl get pod --all-namespaces

出现下面的情况说明基本按照成功

NAMESPACE     NAME                                 READY   STATUS    RESTARTS   AGE
kube-system   coredns-5c98db65d4-f4kjf             0/1     Pending   0          58m
kube-system   coredns-5c98db65d4-xqpwd             0/1     Pending   0          58m
kube-system   etcd-k8s-master                      1/1     Running   0          57m
kube-system   kube-apiserver-k8s-master            1/1     Running   0          57m
kube-system   kube-controller-manager-k8s-master   1/1     Running   0          57m
kube-system   kube-proxy-9l9vr                     1/1     Running   0          58m
kube-system   kube-scheduler-k8s-master            1/1     Running   0          57m

11.安装网络插件

kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

出现下面就安装成功啦

[[email protected] ~]# kubectl get pod --all-namespaces
NAMESPACE     NAME                                        READY   STATUS    RESTARTS   AGE
kube-system   coredns-6955765f44-5jclw                    1/1     Running   0          9h
kube-system   coredns-6955765f44-wlr88                    1/1     Running   0          9h
kube-system   etcd-k8s-master                             1/1     Running   0          9h
kube-system   kube-apiserver-k8s-master                   1/1     Running   0          9h
kube-system   kube-controller-manager-k8s-master          1/1     Running   0          9h
kube-system   kube-proxy-vdxpv                            1/1     Running   0          9h
kube-system   kube-scheduler-k8s-master                   1/1     Running   0          9h
kube-system   weave-net-n2wkx                             2/2     Running   0          8h
weave         weave-scope-agent-4l6dl                     1/1     Running   0          9h