标签：kubernetes CentOS kubelet ecs 版本 kubeadm kube root
我们知道kubernetes.io有文档指导我们如何安装kubernetes，例如kubeadm，按照此方法默认安装最新版本的kubernetes，例如当前（2021-05-11）为v1.21.0
如果是学生党搞搞学习或者研究党搞搞研究，那自然是最新的稳定版本最好了，但是作为参加工作的研发人员，事情往往就没那么简单了，产品使用的版本一般都落后于开源版本，半年甚至更久，所以产品研发人员一般需要部署指定版本的kubernetes用于验证某些功能，这就是本文要讲述的内容
安装kubeadm、kubelet和kubectl
参照kubeadm，当执行到“安装kubeadm、kubelet和kubectl”这一步时，会创建一个repo文件：/etc/yum.repos.d/kubernetes.repo，然后执行：yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes安装最新的稳定版本，我们应该在这里区分开来，具体操作如下：
- 从进入到“安装kubeadm、kubelet和kubectl”这一步开始
- 从repo文件内容中可以找到baseurl=xxx，我们打开repos，ctrl+F搜索kubernetes，找到对应的架构，例如我是aarch64，就选择kubernetes-el7-aarch64
- 点击进入后有两个链接，点击repodata，然后点击primary.xml
- 从primary.xml中找到需要的版本，例如我需要的是1.16.0：
- kubectl：http://yum.kubernetes.io/pool/b89f9c89cf0163bfd4f3d1e3a747856fa77b0c8b0bdec747acab95789103560a-kubectl-1.16.0-0.aarch64.rpm
- kubelet：http://yum.kubernetes.io/pool/392b7313850b2cf63cd68d7a5ee6505d9d9e05c7e398d41c93b1e60bc9214310-kubelet-1.16.0-0.aarch64.rpm
- kubeadm：http://yum.kubernetes.io/pool/227fa407cae2ba5e79b3643f007bce0f7982a5c02a22ab2480e921304c85b355-kubeadm-1.16.0-0.aarch64.rpm
- yum安装找到的rpm
yum install -y http://yum.kubernetes.io/pool/b89f9c89cf0163bfd4f3d1e3a747856fa77b0c8b0bdec747acab95789103560a-kubectl-1.16.0-0.aarch64.rpm yum install -y http://yum.kubernetes.io/pool/392b7313850b2cf63cd68d7a5ee6505d9d9e05c7e398d41c93b1e60bc9214310-kubelet-1.16.0-0.aarch64.rpm yum install -y http://yum.kubernetes.io/pool/227fa407cae2ba5e79b3643f007bce0f7982a5c02a22ab2480e921304c85b355-kubeadm-1.16.0-0.aarch64.rpm - kubeadm version确认安装情况
[root@ecs-57f4 ~]# kubeadm version kubeadm version: &version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:34:01Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/arm64"}
注意：除了安装kubeadm、kubectl、kubelet外，其他步骤按照指导文档执行
使用kubeadm安装kubernetes集群
需要注意的是，通过--kubernetes-version指定kubernetes的版本，具体命令如下
kubeadm init --kubernetes-version 1.16.0 --pod-network-cidr 10.0.0.0/16我使用的是crio v1.21.0作为容器运行时，遇到了kubelet跟crio的cgroup driver不匹配的问题，具体解决的办法是：systemctl status kubelet 可以看到Drop-In: /usr/lib/systemd/system/kubelet.service.d 下面kubeadm添加了一个配置文件：10-kubeadm.conf，修改改文件，增加KUBELET_CGROUP_ARGS（注意：需要改两行，一是新增Environment，二是ExecStart后面添加该参数）：
# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=systemd"
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS $KUBELET_CGROUP_ARGS等待kubeadm安装完成即可
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[kubelet-check] Initial timeout of 40s passed.
[apiclient] All control plane components are healthy after 213.501765 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.16" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Skipping phase. Please see --upload-certs
[mark-control-plane] Marking the node ecs-57f4 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node ecs-57f4 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 7524n3.ctfh768j7xi6d4qy
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
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 192.168.0.45:6443 --token 7524n3.ctfh768j7xi6d4qy \
--discovery-token-ca-cert-hash sha256:8c244d0a30da0d0d950609ee8fddff5f28b1bd76de21ecfe682923830450655d
[root@ecs-57f4 ~]#此时我们执行：kubectl get node会发现node状态为NotReady，不要慌，安装一下网络插件即可
安装网络插件
我选择的是flannel，按照指定kubernetes 1.17+可以一条命令搞定，但我安装的是1.16.0，所以点击链接继续研究，发现：
For Kubernetes v1.16
kube-flannel.yamlusesClusterRole&ClusterRoleBindingofrbac.authorization.k8s.io/v1. When you use Kubernetes v1.16, you should replacerbac.authorization.k8s.io/v1torbac.authorization.k8s.io/v1beta1becauserbac.authorization.k8s.io/v1had become GA from Kubernetes v1.17.
所以安装脚本修改为：
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i 's#rbac.authorization.k8s.io/v1#rbac.authorization.k8s.io/v1beta1#g' kube-flannel.yml
kubectl apply -f kube-flannel.yml然后执行命令：kubectl get po -A 等待所以pod编程Running即可
验证
[root@ecs-57f4 ~]# kubectl get node -owide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
ecs-57f4 Ready master 62m v1.16.0 192.168.0.45 <none> CentOS Linux 7 (AltArch) 4.18.0-80.7.2.el7.aarch64 cri-o://1.21.0
[root@ecs-57f4 ~]#
[root@ecs-57f4 ~]#
[root@ecs-57f4 ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:36:53Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/arm64"}
Server Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:27:17Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/arm64"}
[root@ecs-57f4 ~]# kubectl get node -owide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
ecs-57f4 Ready master 62m v1.16.0 192.168.0.45 <none> CentOS Linux 7 (AltArch) 4.18.0-80.7.2.el7.aarch64 cri-o://1.21.0
[root@ecs-57f4 ~]# kubectl get po -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-5644d7b6d9-5jqvz 1/1 Running 0 66m
kube-system coredns-5644d7b6d9-zzn9c 1/1 Running 0 66m
kube-system etcd-ecs-57f4 1/1 Running 0 65m
kube-system kube-apiserver-ecs-57f4 1/1 Running 0 65m
kube-system kube-controller-manager-ecs-57f4 1/1 Running 0 65m
kube-system kube-flannel-ds-7vk9n 1/1 Running 0 62m
kube-system kube-proxy-c5m8c 1/1 Running 0 66m
kube-system kube-scheduler-ecs-57f4 1/1 Running 0 65m我们再部署一个应用做简单的测试
[root@ecs-57f4 ~]# cat nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
selector:
matchLabels:
app: nginx
replicas: 1 # tells deployment to run 2 pods matching the template
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: docker.io/library/nginx:1.14.2
ports:
- containerPort: 80
[root@ecs-57f4 ~]# kubectl apply -f nginx-deployment.yaml
deployment.apps/nginx created
[root@ecs-57f4 ~]# kubectl get po
NAME READY STATUS RESTARTS AGE
nginx-685d968c9-xzl6f 1/1 Running 0 5s
[root@ecs-57f4 ~]# kubectl exec -it nginx-685d968c9-xzl6f -- ls -lh
total 64K
drwxr-xr-x 1 root root 4.0K Mar 27 2019 bin
drwxr-xr-x 2 root root 4.0K Feb 3 2019 boot
drwxr-xr-x 5 root root 360 May 11 09:13 dev
drwxr-xr-x 1 root root 4.0K May 11 09:13 etc
drwxr-xr-x 2 root root 4.0K Feb 3 2019 home
drwxr-xr-x 1 root root 4.0K Mar 27 2019 lib
drwxr-xr-x 2 root root 4.0K Mar 26 2019 media
drwxr-xr-x 2 root root 4.0K Mar 26 2019 mnt
drwxr-xr-x 2 root root 4.0K Mar 26 2019 opt
dr-xr-xr-x 185 root root 0 May 11 09:13 proc
drwx------ 2 root root 4.0K Mar 26 2019 root
drwxr-xr-x 1 root root 4.0K May 11 09:13 run
drwxr-xr-x 2 root root 4.0K Mar 26 2019 sbin
drwxr-xr-x 2 root root 4.0K Mar 26 2019 srv
dr-xr-xr-x 12 root root 0 May 11 09:13 sys
drwxrwxrwt 1 root root 4.0K Mar 27 2019 tmp
drwxr-xr-x 1 root root 4.0K Mar 26 2019 usr
drwxr-xr-x 1 root root 4.0K Mar 26 2019 var
[root@ecs-57f4 ~]#参考链接
标签：kubernetes,CentOS,kubelet,ecs,版本,kubeadm,kube,root 来源： https://blog.csdn.net/CuriousAn/article/details/116660410
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