1 kubeadm方式安装k8s集群
1.1 环境准备
配置本地hosts
[root@master ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.1.2 master 192.168.1.3 node01 192.168.1.4 node02
配置master到两台node节点免密登陆
[root@master ~]# ssh-keygen [root@master ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub master [root@master ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub node01 [root@master ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub node02
1.2 container runtime
容器运行时：为了让容器运行在pod里，k8s设计了容器运行时。这里我们采用docker。
需要在三台节点进行安装配置。
（1）配置阿里云yum源
# step 1: 安装必要的一些系统工具 sudo yum install -y yum-utils device-mapper-persistent-data lvm2 # Step 2: 添加软件源信息 sudo yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo # Step 3: 更新并安装Docker-CE sudo yum makecache fast sudo yum -y install docker-ce # Step 4: 开启Docker服务 sudo service docker start # 注意： # 官方软件源默认启用了最新的软件，您可以通过编辑软件源的方式获取各个版本的软件包。例如官方并没有将测试版本的软件源置为可用，您可以通过以下方式开启。同理可以开启各种测试版本等。 # vim /etc/yum.repos.d/docker-ee.repo # 将[docker-ce-test]下方的enabled=0修改为enabled=1 # # 安装指定版本的Docker-CE: # Step 1: 查找Docker-CE的版本: # yum list docker-ce.x86_64 --showduplicates | sort -r # Loading mirror speeds from cached hostfile # Loaded plugins: branch, fastestmirror, langpacks # docker-ce.x86_64 17.03.1.ce-1.el7.centos docker-ce-stable # docker-ce.x86_64 17.03.1.ce-1.el7.centos @docker-ce-stable # docker-ce.x86_64 17.03.0.ce-1.el7.centos docker-ce-stable # Available Packages # Step2: 安装指定版本的Docker-CE: (VERSION例如上面的17.03.0.ce.1-1.el7.centos) # sudo yum -y install docker-ce-[VERSION]
yum install docker-ce-19.03.13-3.el7.x86_64 -y
安装一些包
yum install net-tools.x86_64 wget lrzsz telnet tree nmap sysstat dos2unix bind-utils -y
（2）对docker做一些简单的配置
registry-mirrors：字段为阿里云镜像加速地址，需要注册阿里云用户。
exec-opts：中配置了cgroupdriver为systemd，这是因为k8s集群规定的。
[root@master ~]# cat /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2",
"storage-opts": [
"overlay2.override_kernel_check=true"
],
"registry-mirrors": ["https://xxxxx.mirror.aliyuncs.com"]
}
（3）启动docker
systemctl start docker
systemctl enable docker
docker version
docker info
1.3 安装kubeadm、kubectl、kubelet
kubeadm：集群初始化工具
kubectl：命令行工具
kubelet：node节点必备服务，主要是启动pod并监控pod状态的组件
（1）设置iptables
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF sysctl --system
（2）配置阿里源
cat <<EOF > /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
（3）安装（所有节点）
yum install -y kubelet-1.18.0-0.x86_64 kubeadm-1.18.0-0.x86_64 kubectl-1.18.0-0.x86_64 -y
设置kubelet开机自启动
systemctl enable kubelet.service
1.4 部署集群
由于kubeadm默认会从谷歌拉取镜像，国内环境无法获取，建议提前准备好docker镜像；
1.3安装的kubeadm版本为1.18.0，需要准备1.18.15版本的其他包。
获取安装包地址：https://www.sealyun.com/goodsDetail?type=cloud_kernel&name=kubernetes 需要付费
上传至所有节点
[root@myhost01 src]# ls kube kube1.18.15.tar.gz [root@myhost01 ~]# docker load -i /opt/app/src/kube/images/images.tar [root@myhost01 ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE k8s.gcr.io/kube-proxy v1.18.15 6947b0d99ceb 11 days ago 117MB k8s.gcr.io/kube-controller-manager v1.18.15 4b3915bbba95 11 days ago 162MB k8s.gcr.io/kube-apiserver v1.18.15 21e89bb12d33 11 days ago 173MB k8s.gcr.io/kube-scheduler v1.18.15 db6167a559ba 11 days ago 95.3MB fanux/lvscare latest 38af5ed07c1b 4 weeks ago 14.9MB k8s.gcr.io/pause 3.2 80d28bedfe5d 11 months ago 683kB k8s.gcr.io/coredns 1.6.7 67da37a9a360 12 months ago 43.8MB k8s.gcr.io/etcd 3.4.3-0 303ce5db0e90 15 months ago 288MB calico/node v3.8.2 11cd78b9e13d 17 months ago 189MB calico/cni v3.8.2 c71c24a0b1a2 17 months ago 157MB calico/kube-controllers v3.8.2 de959d4e3638 17 months ago 46.8MB calico/pod2daemon-flexvol v3.8.2 96047edc008f 17 months ago 9.37MB
[root@myhost01 ~]# scp /opt/app/src/kube/images/images.tar root@myhost02:/opt/app/src/kube/images
images.tar 100% 1030MB 132.8MB/s 00:07
[root@myhost01 ~]# scp /opt/app/src/kube/images/images.tar root@myhost03:/opt/app/src/kube/images
images.tar
[root@myhost02 ~]# docker load -i /opt/app/src/kube/images/images.tar
[root@myhost03 ~]# docker load -i /opt/app/src/kube/images/images.tar
报错：
[root@master ~]# kubeadm init --pod-network-cidr 172.16.0.0/16
[init] Using Kubernetes version: v1.20.2
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 20.10.2. Latest validated version: 19.03
error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR Swap]: running with swap on is not supported. Please disable swap
[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
解决：
关闭swap
[root@master ~]# swapoff -a
注释掉/etc/fstab关于swap分区挂在行，否则重启后kubelet服务无法启动。
[root@myhost01 ~]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Wed Nov 20 16:58:21 2019 # # 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 # /dev/mapper/centos-root / xfs defaults 0 0 UUID=16ab7706-1680-4322-894d-4d0e69b6fc04 /boot xfs defaults 0 0 #/dev/mapper/centos-swap swap swap defaults 0 0
初始化集群：
出现以下回显代表成功了。
[root@myhost01 ~]# kubeadm init --pod-network-cidr 172.16.0.0/16
I0124 22:19:22.450912 9791 version.go:252] remote version is much newer: v1.20.2; falling back to: stable-1.18
W0124 22:19:23.414525 9791 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.15
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[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 [myhost01 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.1.2]
[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 [myhost01 localhost] and IPs [192.168.1.2 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [myhost01 localhost] and IPs [192.168.1.2 127.0.0.1 ::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"
W0124 22:19:26.893646 9791 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0124 22:19:26.894232 9791 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 20.002420 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 myhost01 as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node myhost01 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: eszovk.7zrv5czhh0q9mv7w
[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 192.168.1.2:6443 --token eszovk.7zrv5czhh0q9mv7w \
--discovery-token-ca-cert-hash sha256:23df01d81c8ec153db14eac60157cd3166f30701985301ca6bd1dd150d1633dd
[root@myhost01 ~]# mkdir .kube/ [root@myhost01 ~]# cp -i /etc/kubernetes/admin.conf .kube/config [root@myhost01 ~]# kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system coredns-66bff467f8-l6mlf 0/1 Pending 0 3m48s kube-system coredns-66bff467f8-lkcbf 0/1 Pending 0 3m48s kube-system etcd-myhost01 1/1 Running 0 4m kube-system kube-apiserver-myhost01 1/1 Running 0 4m kube-system kube-controller-manager-myhost01 1/1 Running 0 4m kube-system kube-proxy-r99vs 1/1 Running 0 3m49s kube-system kube-scheduler-myhost01 1/1 Running 0 4m
在其他节点上执行，并将其加入k8s集群
[root@myhost02 ~]# kubeadm join 192.168.1.2:6443 --token eszovk.7zrv5czhh0q9mv7w --discovery-token-ca-cert-hash sha256:23df01d81c8ec153db14eac60157cd3166f30701985301ca6bd1dd150d1633dd
W0124 22:32:32.730122 9531 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[preflight] Running pre-flight checks
[WARNING Service-Docker]: docker service is not enabled, please run 'systemctl enable docker.service'
[WARNING Service-Kubelet]: kubelet service is not enabled, please run 'systemctl enable kubelet.service'
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Starting the kubelet
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.
[root@myhost02 ~]# systemctl start kubelet [root@myhost02 ~]# systemctl enable kubelet Created symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.
kubelet配置文件：/var/lib/kubelet/config.yaml
查看node节点已经加入，但是状态为NotReady
[root@myhost01 ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION myhost01 NotReady master 18m v1.18.0 myhost02 NotReady <none> 5m23s v1.18.0 myhost03 NotReady <none> 6s v1.18.0
1.5 安装网络插件：CNI
在CNI正式启动之前coreDNS都不会正常运行。
CNI网络插件实现了：
node和node之间网络互通
pod和pod之间网络互通
node和pod之间网络互通
下载calico的yaml文件
[root@myhost01 yaml]# wget https://docs.projectcalico.org/v3.8/manifests/calico.yaml
改yaml文件中指定的版本为3.8.9,需要修改了3.8.2，因为我们准备的镜像都是3.8.2版本
应用配置文件
[root@myhost01 yaml]# kubectl apply -f calico.yaml
CNI完成后应该达到的预期如下
（1）所有pod正常运行
（2） 所有node节点状态为Read
（3）集群健康
查看资源简写
[root@myhost01 yaml]# kubectl api-resources
1.6 kubectl命令补全
[root@myhost01 yaml]# rpm -qa | grep completion
bash-completion-2.1-8.el7.noarch
[root@myhost01 yaml]# kubectl completion bash > /etc/profile.d/kubectl.sh
[root@myhost01 yaml]# source /etc/profile.d/kubectl.sh
[root@myhost01 yaml]# vim /root/.bashrc
[root@myhost01 yaml]# cat /root/.bashrc
# .bashrc
# User specific aliases and functions
alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
source /etc/profile.d/kubectl.sh