使用kubeadm在Centos8上部署kubernetes1.18

1 系统准备

查看系统版本

[root@localhost]# cat /etc/centos-release
CentOS Linux release 8.1.1911 (Core)


配置网络

[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-enp0s3
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_OnLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCOnF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=enp0s3
UUID=039303a5-c70d-4973-8c91-97eaa071c23d
DEVICE=enp0s3
OnBOOT=yes
IPADDR=192.168.122.21
NETMASK=255.255.255.0
GATEWAY=192.168.122.1
DNS1=223.5.5.5


添加阿里源

[root@localhost ~]# rm -rfv /etc/yum.repos.d/*
[root@localhost ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-8.repo


配置主机名

[root@master01 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.122.21 master01.paas.com master01


关闭swap，注释swap分区

[root@master01 ~]# swapoff -a
[root@master01 ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Tue Mar 31 22:44:34 2020
#
# Accessible filesystems, by reference, are maintained under '/dev/disk/'.
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info.
#
# After editing this file, run 'systemctl daemon-reload' to update systemd
# units generated from this file.
#
/dev/mapper/cl-root / xfs defaults 0 0
UUID=5fecb240-379b-4331-ba04-f41338e81a6e /boot ext4 defaults 1 2
/dev/mapper/cl-home /home xfs defaults 0 0
#/dev/mapper/cl-swap swap swap defaults 0 0


配置内核参数，将桥接的IPv4流量传递到iptables的链

[root@master01 ~]# cat > /etc/sysctl.d/k8s.conf <net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system


2 安装常用包

[root@master01 ~]# yum install vim bash-completion net-tools gcc -y


3 使用aliyun源安装docker-ce

[root@master01 ~]# yum install -y yum-utils device-mapper-persistent-data lvm2
[root@master01 ~]# yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
[root@master01 ~]# yum -y install docker-ce


安装docker-ce如果出现以下错

[root@master01 ~]# yum -y install docker-ce
CentOS-8 - Base - mirrors.aliyun.com 14 kB/s | 3.8 kB 00:00
CentOS-8 - Extras - mirrors.aliyun.com 6.4 kB/s | 1.5 kB 00:00
CentOS-8 - AppStream - mirrors.aliyun.com 16 kB/s | 4.3 kB 00:00
Docker CE Stable - x86_64 40 kB/s | 22 kB 00:00
Error:
Problem: package docker-ce-3:19.03.8-3.el7.x86_64 requires containerd.io >= 1.2.2-3, but none of the providers can be installed
- cannot install the best candidate for the job
- package containerd.io-1.2.10-3.2.el7.x86_64 is excluded
- package containerd.io-1.2.13-3.1.el7.x86_64 is excluded
- package containerd.io-1.2.2-3.3.el7.x86_64 is excluded
- package containerd.io-1.2.2-3.el7.x86_64 is excluded
- package containerd.io-1.2.4-3.1.el7.x86_64 is excluded
- package containerd.io-1.2.5-3.1.el7.x86_64 is excluded
- package containerd.io-1.2.6-3.3.el7.x86_64 is excluded
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)


解决方法

[root@master01 ~]# wget https://download.docker.com/linux/centos/7/x86_64/edge/Packages/containerd.io-1.2.6-3.3.el7.x86_64.rpm
[root@master01 ~]# yum install containerd.io-1.2.6-3.3.el7.x86_64.rpm


然后再安装docker-ce即可成功

添加aliyundocker仓库加速器

[root@master01 ~]# mkdir -p /etc/docker
[root@master01 ~]# tee /etc/docker/daemon.json <<-'EOF'
{
"registry-mirrors": ["https://fl791z1h.mirror.aliyuncs.com"]
}
EOF
[root@master01 ~]# systemctl daemon-reload
[root@master01 ~]# systemctl restart docker


4 安装kubectl、kubelet、kubeadm

添加阿里kubernetes源

[root@master01 ~]# 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


安装

[root@master01 ~]# yum install kubectl kubelet kubeadm
[root@master01 ~]# systemctl enable kubelet


5 初始化k8s集群

[root@master01 ~]# kubeadm init --kubernetes-version=1.18.0 \
--apiserver-advertise-address=192.168.122.21 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.10.0.0/16 --pod-network-cidr=10.122.0.0/16


POD的网段为: 10.122.0.0/16， api server地址就是master本机IP。

这一步很关键，由于kubeadm 默认从官网k8s.grc.io下载所需镜像，国内无法访问，因此需要通过–image-repository指定阿里云镜像仓库地址。

集群初始化成功后返回如下信息：

W0408 09:36:36.121603 14098 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.0
[preflight] Running pre-flight checks
[WARNING FileExisting-tc]: tc not found in system path
[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'
[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
[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 [master01.paas.com kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.10.0.1 192.168.122.21]
[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 [master01.paas.com localhost] and IPs [192.168.122.21 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [master01.paas.com localhost] and IPs [192.168.122.21 127.0.0.1 ::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
[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"
W0408 09:36:43.343191 14098 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0408 09:36:43.344303 14098 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[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". This can take up to 4m0s
[apiclient] All control plane components are healthy after 23.002541 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.18" 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 master01.paas.com as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node master01.paas.com as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: v2r5a4.veazy2xhzetpktfz
[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 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
[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
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 192.168.122.21:6443 --token v2r5a4.veazy2xhzetpktfz \
--discovery-token-ca-cert-hash sha256:daded8514c8350f7c238204979039ff9884d5b595ca950ba8bbce80724fd65d4
[root@master01 ~]#


记录生成的最后部分内容，此内容需要在其它节点加入Kubernetes集群时执行。

根据提示创建kubectl

[root@master01 ~]# mkdir -p $HOME/.kube
[root@master01 ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@master01 ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config


执行下面命令，使kubectl可以自动补充

[root@master01 ~]# source <(kubectl completion bash)


查看节点，pod

[root@master01 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
master01.paas.com NotReady master 2m29s v1.18.0
[root@master01 ~]# kubectl get pod --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-7ff77c879f-fsj9l 0/1 Pending 0 2m12s
kube-system coredns-7ff77c879f-q5ll2 0/1 Pending 0 2m12s
kube-system etcd-master01.paas.com 1/1 Running 0 2m22s
kube-system kube-apiserver-master01.paas.com 1/1 Running 0 2m22s
kube-system kube-controller-manager-master01.paas.com 1/1 Running 0 2m22s
kube-system kube-proxy-th472 1/1 Running 0 2m12s
kube-system kube-scheduler-master01.paas.com 1/1 Running 0 2m22s
[root@master01 ~]#


node节点为NotReady，因为corednspod没有启动，缺少网络pod

6 安装calico网络

[root@master01 ~]# kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml
configmap/calico-config created
customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org created
customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org created
clusterrole.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created
clusterrole.rbac.authorization.k8s.io/calico-node created
clusterrolebinding.rbac.authorization.k8s.io/calico-node created
daemonset.apps/calico-node created
serviceaccount/calico-node created
deployment.apps/calico-kube-controllers created
serviceaccount/calico-kube-controllers created


查看pod和node

[root@master01 ~]# kubectl get pod --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system calico-kube-controllers-555fc8cc5c-k8rbk 1/1 Running 0 36s
kube-system calico-node-5km27 1/1 Running 0 36s
kube-system coredns-7ff77c879f-fsj9l 1/1 Running 0 5m22s
kube-system coredns-7ff77c879f-q5ll2 1/1 Running 0 5m22s
kube-system etcd-master01.paas.com 1/1 Running 0 5m32s
kube-system kube-apiserver-master01.paas.com 1/1 Running 0 5m32s
kube-system kube-controller-manager-master01.paas.com 1/1 Running 0 5m32s
kube-system kube-proxy-th472 1/1 Running 0 5m22s
kube-system kube-scheduler-master01.paas.com 1/1 Running 0 5m32s
[root@master01 ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
master01.paas.com Ready master 5m47s v1.18.0
[root@master01 ~]#


Roosevelt