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Install and configure master, the master node running Kubernetes, which includes the database of etcd, that is, etcd is not separate from the master node and is used for odd-numbered master node installations.

1. Generate the warehouse configuration file # cat kubeadm-init-config.yaml for kubernets

Modify the configuration file (check the following section)

... apiVersion: kubeadm.k8s.io/v1beta2certificatesDir: / etc/kubernetes/pkiclusterName: kubernetes...dns: type: CoreDNSetcd: local: dataDir: / var/lib/etcd...kind: ClusterConfigurationkubernetesVersion: v1.16.2networking: dnsDomain: cluster.test serviceSubnet: 10.96.0.0/16 podSubnet: 10.244.0.0/16...

Initialize using the command

Kubeadm init- f kubeadm-init-config.yaml

The configuration file for the offline environment initializes the root online environment, but the image file needs to be imported first.

4) initialize subsequent operations

Next, according to the above initialization results, you need to prepare the kubectl environment and install the network for the users of the current master node.

Create the folder $mkdir-p ~ / .kube$ cp / etc/kubernetes/admin.conf ~ / .kube / config install the network plug-in syntax: "kubectl apply-f [podnetwork] .yaml"

The flannel we use here (developed by coreos). There are specific installation instructions on the github page, address https://github.com/coreos/flannel.

# kubectl apply-f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

If it is an offline installation, you can download the packaged flannel image and kube-flannel.yml file first, and then install it using kubectl. The details are as follows:

Download flannel

Docker pull query.io/coreos/flannel

Package flannel and save it locally

Docker save query.io/coreos/flannel-o / flannel-0.11.0.tar

Mount flannel Mirror

Docker load-I / flannel-0.11.0.tar

Download the kube-flannel.yml file

Wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

Install flannel

Kubectl apply-f kube-flannel.yml

You can then use the command "kubectl get pods-n kube-system" to view it.

Reference:

Kubeadm-config.yaml configuration syntax reference: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2kubeadm-config.yaml configuration master node: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/control-plane-flags/kube-proxy enable ipvs: https://github.com/kubernetes/kubernetes/blob/master/pkg/proxy/ipvs/README.mdkubelet configuration example reference: https://kubernetes.io / docs/setup/production-environment/tools/kubeadm/kubelet-integration/#configure-kubelets-using-kubeadm5) additional note: kubeadm-config.yaml composition deployment description: InitConfiguration: used to define some initialization configurations ClusterConfiguration, such as token used for initialization and apiserver address: used to define configuration items related to master components such as apiserver, etcd, network, scheduler, controller-manager, etc. KubeletConfiguration: used to define configuration items related to kubelet components KubeProxyConfiguration: used to define configuration items related to kube-proxy components

As you can see, there are only InitConfiguration and ClusterConfiguration parts in the default kubeadm-config.yaml file. We can generate sample files for the other two parts by doing the following:

# generate KubeletConfiguration sample file kubeadm config print init-defaults-- component-configs KubeletConfiguration# generate KubeProxyConfiguration sample file kubeadm config print init-defaults-- docker version approved by kubernete during component-configs KubeProxyConfigurationkubeadm initialization [WARNING SystemVerification]: this docker version is not on the list of validated version: 19.01.1. Latest validated version: 18.06

The above version varies according to the report version of your environment. You can refer to the changelog file of kubernetes in the git repository to determine which docker version is supported, and then follow the command

# yum list docker-ce.x86_64-- showduplicates | sort-r

Get a list of versions and select a specific version to install

Sudo yum-y install docker-ce- [VERSION] kubeadm initialization kubelet is not set for self-startup [WARNING Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service'

Solution: execute the self-startup command 'systemctl enable kubelet.service'

Kubeadm initialization does not disable swap: [error Swap]: running with swap on is not enabled, please disable swap [preflight] If you know what you are doing, you can make a check non-fatal with'--ignore-preflight-errors=...'

Solution: you can add the parameter'--ignore-preflight-errors=Swap' to the end of the kubeadm command.

View the configuration of initialized kubeadm kubeadm config viewmaster node participation workload

For clusters initialized with kubeadm, Pod is not scheduled to Master Node for security reasons, which means that Master Node does not participate in the workload. This is because the current master node (such as the name master0) is tainted with node-role.kubernetes.io/master:NoSchedule:

$sudo kubectl describe node master0 | grep TaintTaints: node-role.kubernetes.io/master:NoSchedule

Because the test environment is built here, or for some other reason, you need to remove this stain and allow master0 to participate in the workload:

$sudo kubectl taint nodes master0 node-role.kubernetes.io/master-node "master0" untainted

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