Kubeadm 初始化Kubernetes手记
安装步骤
0. 安装要求
- CPU 2cores
- Memory 2GB
1. 禁用Swap
sysctl -w vm.swappiness=0
echo "vm.swappiness = 0">> /etc/sysctl.conf
swapoff -a
free -m # 查看内存使用情况
2. 安装kubelet,kubeadmin,kubectl
cat < /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
# Set SELinux in permissive mode (effectively disabling it)
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
systemctl enable --now kubelet
3. 初始化Master节点
[root@localhost ~]# kubeadm init --pod-network-cidr=192.168.0.0/16
如下是输出
W0823 01:26:08.812271 17297 version.go:98] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get https://dl.k8s.io/release/stable-1.txt: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
W0823 01:26:08.812343 17297 version.go:99] falling back to the local client version: v1.15.3
[init] Using Kubernetes version: v1.15.3
[preflight] Running pre-flight checks
[WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.1. Latest validated version: 18.09
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-apiserver:v1.15.3: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-controller-manager:v1.15.3: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-scheduler:v1.15.3: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/kube-proxy:v1.15.3: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/pause:3.1: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/etcd:3.3.10: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[ERROR ImagePull]: failed to pull image k8s.gcr.io/coredns:1.3.1: output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
如上提示，初始化时提示镜像下载失败!
4. 手动下载镜像并打标签
注意版本号
docker pull mirrorgooglecontainers/kube-apiserver-amd64:v1.15.3
docker tag mirrorgooglecontainers/kube-apiserver-amd64:v1.15.3 k8s.gcr.io/kube-apiserver:v1.15.3
docker pull mirrorgooglecontainers/kube-controller-manager-amd64:v1.15.3
docker tag mirrorgooglecontainers/kube-controller-manager-amd64:v1.15.3 k8s.gcr.io/kube-controller-manager:v1.15.3
docker pull mirrorgooglecontainers/kube-scheduler-amd64:v1.15.3
docker tag mirrorgooglecontainers/kube-scheduler-amd64:v1.15.3 k8s.gcr.io/kube-scheduler:v1.15.3
docker pull mirrorgooglecontainers/kube-proxy-amd64:v1.15.3
docker tag mirrorgooglecontainers/kube-proxy-amd64:v1.15.3 k8s.gcr.io/kube-proxy:v1.15.3
docker pull mirrorgooglecontainers/pause-amd64:3.1
docker tag mirrorgooglecontainers/pause-amd64:3.1 k8s.gcr.io/pause:3.1
docker pull mirrorgooglecontainers/etcd-amd64:3.3.10
docker tag mirrorgooglecontainers/etcd-amd64:3.3.10 k8s.gcr.io/etcd:3.3.10
docker pull coredns/coredns:1.3.1
docker tag coredns/coredns:1.3.1 k8s.gcr.io/coredns:1.3.1
5. 再次初始化
kubeadm init --pod-network-cidr=192.168.0.0/16
...
Your Kubernetes control-plane has initialized successfully!
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
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 192.168.10.133:6443 --token imib5y.nl5kp2qyczt2pf0c \
--discovery-token-ca-cert-hash sha256:f4185a63eecf4f290484e1c917af9144eb6bea57f4694ae72b5b5f769e2c5b68
6. 创建配置目录
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
7. 安装网络
kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/calico.yaml
8. 创建token
查看token
kubeadm token list
默认token有效期24小时，添加worker节点时需要使用–discovery-token-ca-cert-hash，通过如下命令生成token
kubeadm token create
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | \
openssl dgst -sha256 -hex | sed 's/^.* //'
9. 开启Schedule
默认情况下Master节点不执行Pods,通过如下命令开启
kubectl taint nodes --all node-role.kubernetes.io/master-