master 192.168.2.18node1 192.168.2.19，今天小编就来聊一聊关于kubernetes 最低配置?接下来我们就一起去研究一下吧!
kubernetes 最低配置
环境介绍：master 192.168.2.18
node1 192.168.2.19
node2 192.168.2.20
CentOS 7.5
Docker 19.03.13
2核 CPU，2GB 内存
报错信息：初始化Kubernetes时出现下面报错
[root@k8s-master ~]# kubeadm init --kubernetes-version=v1.22.1 --apiserver-advertise-address=192.168.1.18 --image-repository registry.aliyuncs.com/google_containers=10.1.0.0/16 --pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.22.1
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[WARNING Hostname]: hostname "k8s-master" could not be reached
[WARNING Hostname]: hostname "k8s-master": lookup k8s-master on 192.168.1.1:53: no such host
[preflight] Pulling images required for setting up a Kubernetes cluster
...
...
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthzefused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthzefused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthzefused.
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz
[kubelet-check] It seems like the kubelet isn't running or healthy.
[kubelet-check] The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get "http://localhost:10248/healthz
...
在/etc/docker/daemon.json文件中加入“"exec-opts": ["native.cgroupdriver=systemd"]一行配置，重启docker跟清除一下kubeadm信息即可重新初始化。”
[root@k8s-node2 ~]# vim /etc/docker/daemon.json
...
"exec-opts": ["native.cgroupdriver=systemd"],
...
[root@k8s-node2 ~]# systemctl restart docker
[root@k8s-master ~]# kubeadm reset -f
注意：
当出现同样这个报错，如果使用以上这个方法无法解决时，也可以试试另外一种方法，也是我其中一次遇到并且使用该方法解决过的。
初始化Kubenetes报错1：https://blog.csdn.net/qq_44895681/article/details/10741…
可能出现的报错：
在安装部署Kubenetes的过程中出现的任何报错，尝试解决报错问题后，最好是先执行一次kubeadm reset -f来清除一下kubeadm的信息，再进行验证错误是否得到解决，不然可能上个报错没有解决又出现以下或者新的报错。
[root@k8s-master ~]# kubeadm init --kubernetes-version=v1.22.1 --apiserver-advertise-address=192.168.1.18 --image-repository registry.aliyuncs.com/google0.0/16
[init] Using Kubernetes version: v1.22.1
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[WARNING Hostname]: hostname "k8s-master" could not be reached
[WARNING Hostname]: hostname "k8s-master": lookup k8s-master on 192.168.1.1:53: no such host
error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR Port-6443]: Port 6443 is in use
[ERROR Port-10259]: Port 10259 is in use
[ERROR Port-10257]: Port 10257 is in use
[ERROR FileAvailable--etc-kubernetes-manifests-kube-apiserver.yaml]: /etc/kubernetes/manifests/kube-apiserver.yaml already exis
[ERROR FileAvailable--etc-kubernetes-manifests-kube-controller-manager.yaml]: /etc/kubernetes/manifests/kube-controller-manager
[ERROR FileAvailable--etc-kubernetes-manifests-kube-scheduler.yaml]: /etc/kubernetes/manifests/kube-scheduler.yaml already exis
[ERROR FileAvailable--etc-kubernetes-manifests-etcd.yaml]: /etc/kubernetes/manifests/etcd.yaml already exists
[ERROR Port-10250]: Port 10250 is in use
[ERROR Port-2379]: Port 2379 is in use
[ERROR Port-2380]: Port 2380 is in use
[ERROR DirAvailable--var-lib-etcd]: /var/lib/etcd is not empty
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`
To see the stack trace of this error execute with --v=5 or higher
[root@k8s-master ~]# kubeadm reset -f --- 清除/重置kubeadm
在执行完kubeadm reset -f后验证，发现不会再出现上面的报错。（继续进行下面的验证，看看问题是否得到解决）
验证：重新初始化Kubernetes
[root@k8s-master ~]# kubeadm init --kubernetes-version=v1.22.1 --apiserver-advertise-address=192.168.1.18 --image-repository registry.aliyuncs.com/google0.0/16
[init] Using Kubernetes version: v1.22.1
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[WARNING Hostname]: hostname "k8s-master" could not be reached
[WARNING Hostname]: hostname "k8s-master": lookup k8s-master on 192.168.1.1:53: no such host
[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'
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.defa
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.1.18 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.1.18 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". Th
[apiclient] All control plane components are healthy after 6.002108 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.22" 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 k8s-master as control-plane by adding the labels: [node-role.kubernetes.io/master(deprecated) nod
[mark-control-plane] Marking the node k8s-master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: 9t2nu9.00ieyfqmc50dgub6
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate cre
[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
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[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
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 192.168.1.18:6443 --token 9t2nu9.00ieyfqmc50dgub6 \
--discovery-token-ca-cert-hash sha256:183b6c95b4e49f0bd4074c61aeefc56d70215240fbeb7a633afe3526006c4dc9
初始化成功，问题解决！
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