Kubernetes 安装篇（下）：基于 Kubeadm 方式的集群部署
发布于: 2021 年 02 月 04 日
1、环境准备
采用 VMware 虚拟机安装 Kubernetes 集群，准备环境情况如下：
2 台虚拟机：CentOS 7，配置越高越好！
Docker Version：19.03.13
kubeadm Version：V1.20.0
2、系统初始化
在安装之前，一些系统参数、配置需统一配置，确保后续安装的顺利进行。
系统初始化部分，均需在 Master、Node 节点上执行。
2.1 设置系统主机名
hostnamectl set-hostname <hostname>复制代码
执行过程：
Master 节点
[root@localhost xcbeyond]# hostnamectl set-hostname k8s-master复制代码
Node 节点：
[root@localhost xcbeyond]# hostnamectl set-hostname k8s-node01复制代码
2.2 修改 host 文件
为了方便集群间各节点间可以直接通过主机名互通，因此建议修改 host 文件。
在 Master、node 节点上分别修改 host 文件/etc/hosts，添加以下内容：
192.168.11.100 k8s-master192.168.11.101 k8s-node01复制代码
上述 IP 是对应节点的实际 IP。
2.3 安装依赖包
在接下来 Kubernetes 使用过程中，可能涉及一些工具，事先安装便于后期使用。
yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp net-tools复制代码
2.4 设置防火墙为 Iptables 并设置空规则
systemctl stop firewalld && systemctl disable firewalld
yum -y install iptables-services && systemctl start iptables && systemctl enable iptables&& iptables -F && service iptables save复制代码
2.5 关闭 SELINUX
swapoff -a && sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
# 将SELinux禁用setenforce 0 && sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config复制代码
2.6 调整内核参数
cat > kubernetes.conf <<EOFnet.bridge.bridge-nf-call-iptables=1 # 节点上的iptables能够正确地查看桥接流量net.bridge.bridge-nf-call-ip6tables=1 # 节点上的iptables能够正确地查看桥接流量net.ipv4.ip_forward=1net.ipv4.tcp_tw_recycle=0vm.swappiness=0 # 禁止使用 swap 空间，只有当系统 OOM 时才允许使用它vm.overcommit_memory=1 # 不检查物理内存是否够用vm.panic_on_oom=0 # 开启 OOMfs.inotify.max_user_instances=8192fs.inotify.max_user_watches=1048576fs.file-max=52706963fs.nr_open=52706963net.ipv6.conf.all.disable_ipv6=1net.netfilter.nf_conntrack_max=2310720EOF
cp kubernetes.conf /etc/sysctl.d/kubernetes.conf
sysctl -p /etc/sysctl.d/kubernetes.conf复制代码
2.7 调整时区
(如果时区正确，则无需调整)
# 设置系统时区为中国/上海timedatectl set-timezone Asia/Shanghai
# 将当前的 UTC 时间写入硬件时钟timedatectl set-local-rtc 0
# 重启依赖于系统时间的服务systemctl restart rsyslogsystemctl restart crond复制代码
2.8 升级系统内核为 5.4
CentOS 7.x 系统自带的 3.10.x 内核存在一些 Bugs，导致运行的 Docker、Kubernetes 不稳定，例如： rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
# 安装完成后检查/boot/grub2/grub.cfg中对应内核menuentry中是否包含initrd16配置，如果没有，再安装一次！yum --enablerepo=elrepo-kernel install -y kernel-lt
# 设置开机从新内核启动grub2-set-default 'CentOS Linux (5.4.93-1.el7.elrepo.x86_64) 7 (Core)'复制代码
执行过程：
[root@k8s-master xcbeyond]# uname -r3.10.0-1127.19.1.el7.x86_64[root@k8s-master xcbeyond]# rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm获取http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm警告：/var/tmp/rpm-tmp.xF145X: 头V4 DSA/SHA1 Signature, 密钥 ID baadae52: NOKEY准备中... ################################# [100%]正在升级/安装... 1:elrepo-release-7.0-3.el7.elrepo ################################# [100%][root@k8s-master xcbeyond]# yum --enablerepo=elrepo-kernel install -y kernel-lt已加载插件：fastestmirror, langpacksLoading mirror speeds from cached hostfile ……警告：RPM 数据库已被非 yum 程序修改。 正在安装 : kernel-lt-5.4.93-1.el7.elrepo.x86_64 1/1 验证中 : kernel-lt-5.4.93-1.el7.elrepo.x86_64 1/1
已安装: kernel-lt.x86_64 0:5.4.93-1.el7.elrepo
完毕！[root@k8s-master xcbeyond]# grub2-set-default 'CentOS Linux (5.4.93-1.el7.elrepo.x86_64) 7 (Core)'[root@k8s-master xcbeyond]# reboot复制代码
重启完成后，查看系统内核已升级成功：
[xcbeyond@k8s-master ~]$ uname -r5.4.93-1.el7.elrepo.x86_64复制代码
别忘了在 node 节点上执行！
2.9 kube-proxy 开启 ipvs 的前置条件
modprobe br_netfilter
cat > /etc/sysconfig/modules/ipvs.modules <<EOF#!/bin/bashmodprobe -- ip_vsmodprobe -- ip_vs_rrmodprobe -- ip_vs_wrrmodprobe -- ip_vs_shmodprobe -- nf_conntrack_ipv4EOF
chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4复制代码
执行过程：
[root@k8s-master xcbeyond]# modprobe br_netfilter[root@k8s-master xcbeyond]# cat > /etc/sysconfig/modules/ipvs.modules <<EOF> #!/bin/bash> modprobe -- ip_vs> modprobe -- ip_vs_rr> modprobe -- ip_vs_wrr> modprobe -- ip_vs_sh> modprobe -- nf_conntrack_ipv4> EOF[root@k8s-master xcbeyond]# chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4modprobe: FATAL: Module nf_conntrack_ipv4 not found.复制代码
别忘了在 node 节点上执行！
3、Docker 安装
此处不再讲述 Docker 安装的过程，具体可参考之前写的文章。
4、安装 kubeadm
4.1 安装 kubeadm、kubectl 和 kubelet
需要在每台机器上（master、node 节点）安装以下的软件包：
kubeadm：用来初始化集群的指令。kubectl：用来与集群通信的命令行工具。kubelet：在集群中的每个节点上用来启动 Pod 和容器等。
（1）配置 Kubernetes 数据源
cat <<EOF > /etc/yum.repos.d/kubernetes.repo[kubernetes]name=Kubernetesbaseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64enabled=1gpgcheck=0repo_gpgcheck=0gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpghttp://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpgEOF复制代码
执行过程：
[root@k8s-master xcbeyond]# cat <<EOF > /etc/yum.repos.d/kubernetes.repo> [kubernetes]> name=Kubernetes> baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64> enabled=1> gpgcheck=0> repo_gpgcheck=0> gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg> http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg> EOF复制代码
（2）安装kubeadm、kubectl、kubelet
yum -y install kubeadm kubectl kubelet复制代码
执行过程：
[root@k8s-master xcbeyond]# yum -y install kubeadm kubectl kubelet已加载插件：fastestmirror, langpacksLoading mirror speeds from cached hostfile * base: mirrors.neusoft.edu.cn * elrepo: mirrors.neusoft.edu.cn * extras: mirrors.neusoft.edu.cn * updates: mirrors.neusoft.edu.cnkubernetes | 1.4 kB 00:00:00 正在解决依赖关系--> 正在检查事务---> 软件包 kubeadm.x86_64.0.1.20.2-0 将被 安装--> 正在处理依赖关系 kubernetes-cni >= 0.8.6，它被软件包 kubeadm-1.20.2-0.x86_64 需要--> 正在处理依赖关系 cri-tools >= 1.13.0，它被软件包 kubeadm-1.20.2-0.x86_64 需要---> 软件包 kubectl.x86_64.0.1.20.2-0 将被 安装---> 软件包 kubelet.x86_64.0.1.20.2-0 将被 安装--> 正在处理依赖关系 socat，它被软件包 kubelet-1.20.2-0.x86_64 需要--> 正在检查事务---> 软件包 cri-tools.x86_64.0.1.13.0-0 将被 安装---> 软件包 kubernetes-cni.x86_64.0.0.8.7-0 将被 安装---> 软件包 socat.x86_64.0.1.7.3.2-2.el7 将被 安装--> 解决依赖关系完成
依赖关系解决
========================================================================================= Package 架构 版本 源 大小=========================================================================================正在安装: kubeadm x86_64 1.20.2-0 kubernetes 8.3 M kubectl x86_64 1.20.2-0 kubernetes 8.5 M kubelet x86_64 1.20.2-0 kubernetes 20 M为依赖而安装: cri-tools x86_64 1.13.0-0 kubernetes 5.1 M kubernetes-cni x86_64 0.8.7-0 kubernetes 19 M socat x86_64 1.7.3.2-2.el7 base 290 k
事务概要=========================================================================================安装 3 软件包 (+3 依赖软件包)
总计：61 M总下载量：52 M安装大小：262 MDownloading packages:(1/5): 14bfe6e75a9efc8eca3f638eb22c7e2ce759c67f95b43b16fae4ebabde1549f3-cri-tools-1.13.0-0.x86_64.rpm | 5.1 MB 00:00:03 (2/5): b46459afb07aaf12937f7f310b876fab9f5f904eaa8f4a88a21547477eafba78-kubeadm-1.20.2-0.x86_64.rpm | 8.3 MB 00:00:06 (3/5): socat-1.7.3.2-2.el7.x86_64.rpm | 290 kB 00:00:02 (4/5): a79d632b1f8c40d2a00e2f98cba68b55c3928d70b97c32aad61c10e17965c2f1-kubelet-1.20.2-0.x86_64.rpm | 20 MB 00:00:14 (5/5): db7cb5cb0b3f6875f54d10f02e625573988e3e91fd4fc5eef0b1876bb18604ad-kubernetes-cni-0.8.7-0.x86_64.rpm | 19 MB 00:00:11 -----------------------------------------------------------------------------------------总计 2.8 MB/s | 52 MB 00:00:18 Running transaction checkRunning transaction testTransaction test succeededRunning transaction 正在安装 : socat-1.7.3.2-2.el7.x86_64 1/6 正在安装 : kubelet-1.20.2-0.x86_64 2/6 正在安装 : kubernetes-cni-0.8.7-0.x86_64 3/6 正在安装 : kubectl-1.20.2-0.x86_64 4/6 正在安装 : cri-tools-1.13.0-0.x86_64 5/6 正在安装 : kubeadm-1.20.2-0.x86_64 6/6 验证中 : kubernetes-cni-0.8.7-0.x86_64 1/6 验证中 : kubelet-1.20.2-0.x86_64 2/6 验证中 : kubeadm-1.20.2-0.x86_64 3/6 验证中 : cri-tools-1.13.0-0.x86_64 4/6 验证中 : kubectl-1.20.2-0.x86_64 5/6 验证中 : socat-1.7.3.2-2.el7.x86_64 6/6
已安装: kubeadm.x86_64 0:1.20.2-0 kubectl.x86_64 0:1.20.2-0 kubelet.x86_64 0:1.20.2-0 作为依赖被安装: cri-tools.x86_64 0:1.13.0-0 kubernetes-cni.x86_64 0:0.8.7-0 socat.x86_64 0:1.7.3.2-2.el7
完毕！复制代码
（3）设置开机启动kubelet
systemctl enable kubelet.service复制代码
执行过程：
[root@k8s-master xcbeyond]# systemctl enable kubelet.serviceCreated symlink from /etc/systemd/system/multi-user.target.wants/kubelet.service to /usr/lib/systemd/system/kubelet.service.复制代码
别忘了在 node 节点上执行！
4.2 创建集群
4.2.1 安装镜像拉取
kubeadm创建集群默认使用的 docker 镜像仓库为k8s.gcr.io，而国内无法直接访问，需要中转才能使用。
（已将所需镜像构建发布在 docker hub 上，方便国内直接使用）
master、node 节点都需要执行！
安装镜像拉取脚本k8s-images-pull.sh如下：
#!/bin/bash
kubernetes_version="v1.20.0"
# 下载需要的镜像(docker hub)kubeadm config images list --kubernetes-version=${kubernetes_version} |sed -e 's/^/docker pull /g' -e 's#k8s.gcr.io#xcbeyond#g' |sh -x
# 重命名镜像docker images |grep xcbeyond |awk '{print "docker tag ",$1":"$2,$1":"$2}' |sed -e 's#xcbeyond#k8s.gcr.io#2' |sh -x
# 删除xcbeyond镜像docker images |grep xcbeyond |awk '{print "docker rmi ", $1":"$2}' |sh -x复制代码
查看需要哪些镜像：
kubeadm config images list
执行过程如下：
[root@k8s-master xcbeyond]# ./k8s-images-pull.sh + docker pull xcbeyond/kube-apiserver:v1.20.0v1.20.0: Pulling from xcbeyond/kube-apiserverf398b465657e: Pull complete cbcdf8ef32b4: Pull complete a9b56b1d4e55: Pull complete Digest: sha256:c54e33e290aa1463eae80f6bd4440af3def87f01f86a37a12ec213eb205e538aStatus: Downloaded newer image for xcbeyond/kube-apiserver:v1.20.0docker.io/xcbeyond/kube-apiserver:v1.20.0+ docker pull xcbeyond/kube-controller-manager:v1.20.0v1.20.0: Pulling from xcbeyond/kube-controller-managerf398b465657e: Already exists cbcdf8ef32b4: Already exists 2ffb969cde54: Pull complete Digest: sha256:5f6321aaa0d9880bd3a96a0d589fc96e912e30f7f5f6d6f53c406eb2b4b20b68Status: Downloaded newer image for xcbeyond/kube-controller-manager:v1.20.0docker.io/xcbeyond/kube-controller-manager:v1.20.0+ docker pull xcbeyond/kube-scheduler:v1.20.0v1.20.0: Pulling from xcbeyond/kube-schedulerf398b465657e: Already exists cbcdf8ef32b4: Already exists 2f71710e6dc2: Pull complete Digest: sha256:10f3ae3ed09f92b3be037e1dd465214046135eabd9879db43b3fe7159a1bae1cStatus: Downloaded newer image for xcbeyond/kube-scheduler:v1.20.0docker.io/xcbeyond/kube-scheduler:v1.20.0+ docker pull xcbeyond/kube-proxy:v1.20.0v1.20.0: Pulling from xcbeyond/kube-proxye5a8c1ed6cf1: Pull complete f275df365c13: Pull complete 6a2802bb94f4: Pull complete cb3853c52da4: Pull complete db342cbe4b1c: Pull complete 9a72dd095a53: Pull complete 6943e8f5bc84: Pull complete Digest: sha256:d583d644b186519597dfdfe420710ab0888927e286ea43b2a6f54ba4329e93e4Status: Downloaded newer image for xcbeyond/kube-proxy:v1.20.0docker.io/xcbeyond/kube-proxy:v1.20.0+ docker pull xcbeyond/pause:3.23.2: Pulling from xcbeyond/pausec74f8866df09: Pull complete Digest: sha256:4dcd2075946239537e21adcf4bb300f07eb5c2c8058d699480f2ae62a5cc5085Status: Downloaded newer image for xcbeyond/pause:3.2docker.io/xcbeyond/pause:3.2+ docker pull xcbeyond/etcd:3.4.13-03.4.13-0: Pulling from xcbeyond/etcd4000adbbc3eb: Already exists d72167780652: Already exists d60490a768b5: Already exists 4a4b5535d134: Pull complete 0dac37e8b31a: Pull complete Digest: sha256:79d32edd429163b1ae404eeb078c75fc2f63fc3d606e0cd57285c832e8181ea3Status: Downloaded newer image for xcbeyond/etcd:3.4.13-0docker.io/xcbeyond/etcd:3.4.13-0+ docker pull xcbeyond/coredns:1.7.01.7.0: Pulling from xcbeyond/corednsc6568d217a00: Pull complete 6937ebe10f02: Pull complete Digest: sha256:4310e3ed7a0a9b82cfb2d31c6a7c102b8d05fef2b0208072b87dc4ceca3c47bbStatus: Downloaded newer image for xcbeyond/coredns:1.7.0docker.io/xcbeyond/coredns:1.7.0+ docker tag xcbeyond/pause:3.2 k8s.gcr.io/pause:3.2+ docker tag xcbeyond/kube-controller-manager:v1.20.0 k8s.gcr.io/kube-controller-manager:v1.20.0+ docker tag xcbeyond/coredns:1.7.0 k8s.gcr.io/coredns:1.7.0+ docker tag xcbeyond/etcd:3.4.13-0 k8s.gcr.io/etcd:3.4.13-0+ docker tag xcbeyond/kube-proxy:v1.20.0 k8s.gcr.io/kube-proxy:v1.20.0+ docker tag xcbeyond/kube-scheduler:v1.20.0 k8s.gcr.io/kube-scheduler:v1.20.0+ docker tag xcbeyond/kube-apiserver:v1.20.0 k8s.gcr.io/kube-apiserver:v1.20.0+ docker rmi xcbeyond/pause:3.2Untagged: xcbeyond/pause:3.2Untagged: xcbeyond/pause@sha256:4dcd2075946239537e21adcf4bb300f07eb5c2c8058d699480f2ae62a5cc5085+ docker rmi xcbeyond/kube-controller-manager:v1.20.0Untagged: xcbeyond/kube-controller-manager:v1.20.0Untagged: xcbeyond/kube-controller-manager@sha256:5f6321aaa0d9880bd3a96a0d589fc96e912e30f7f5f6d6f53c406eb2b4b20b68+ docker rmi xcbeyond/coredns:1.7.0Untagged: xcbeyond/coredns:1.7.0Untagged: xcbeyond/coredns@sha256:4310e3ed7a0a9b82cfb2d31c6a7c102b8d05fef2b0208072b87dc4ceca3c47bb+ docker rmi xcbeyond/etcd:3.4.13-0Untagged: xcbeyond/etcd:3.4.13-0Untagged: xcbeyond/etcd@sha256:79d32edd429163b1ae404eeb078c75fc2f63fc3d606e0cd57285c832e8181ea3+ docker rmi xcbeyond/kube-proxy:v1.20.0Untagged: xcbeyond/kube-proxy:v1.20.0Untagged: xcbeyond/kube-proxy@sha256:d583d644b186519597dfdfe420710ab0888927e286ea43b2a6f54ba4329e93e4+ docker rmi xcbeyond/kube-scheduler:v1.20.0Untagged: xcbeyond/kube-scheduler:v1.20.0Untagged: xcbeyond/kube-scheduler@sha256:10f3ae3ed09f92b3be037e1dd465214046135eabd9879db43b3fe7159a1bae1c+ docker rmi xcbeyond/kube-apiserver:v1.20.0Untagged: xcbeyond/kube-apiserver:v1.20.0Untagged: xcbeyond/kube-apiserver@sha256:c54e33e290aa1463eae80f6bd4440af3def87f01f86a37a12ec213eb205e538a[root@k8s-master xcbeyond]# docker image lsREPOSITORY TAG IMAGE ID CREATED SIZEk8s.gcr.io/pause 3.2 b76329639608 16 hours ago 683kBk8s.gcr.io/kube-controller-manager v1.20.0 630f45a9961f 16 hours ago 116MBk8s.gcr.io/coredns 1.7.0 4e42ad8cda50 21 hours ago 45.2MBk8s.gcr.io/etcd 3.4.13-0 999b6137af27 21 hours ago 253MBk8s.gcr.io/kube-proxy v1.20.0 51912faaf3a3 21 hours ago 118MBk8s.gcr.io/kube-scheduler v1.20.0 62181d1bf9a1 21 hours ago 46.4MBk8s.gcr.io/kube-apiserver v1.20.0 0f7e1178e374 22 hours ago 122MB复制代码
别忘了在 node 节点上执行！
4.2.2 初始化主节点
Master节点是指Kubernetes集群中的控制节点，包括etcd（集群数据库） 和API Server（集群控制的入口进程）。
初始化主节点，执行kubeadm init <args>。
（1）修改kubeadm初始化配置文件。
执行`kubeadm config print init-defaults命令获取kubeadm初始配置文件模板，将其存放在 kubeadm-config.yml：
kubeadm config print init-defaults > kubeadm-config.yml复制代码
并修改以下参数：
localAPIEndpoint: advertiseAddress: 192.168.66.10 # 主节点实际IPkubernetesVersion: v1.20.0networking: podSubnet: "10.244.0.0/16" # serviceSubnet: 10.96.0.0/12# 新增如下内容：---apiVersion: kubeproxy.config.k8s.io/v1alpha1kind: KubeProxyConfigurationfeatureGates: SupportIPVSProxyMode: truemode: ipvs
kubeadm init --config=kubeadm-config.yml --upload-certs | tee kubeadm-init.log复制代码
（2）初始化。
kubeadm init --config=kubeadm-config.yml | tee kubeadm-init.log复制代码
方便初始化日志查看，将其留存在 kubeadm-init.log 文件。
如果说某次执行
kubeadm init初始化失败，在下一次执行kubeadm init初始化语句之前，先执行kubeadm reset命令。这个命令的作用是重置节点，可以把这个命令理解为：上一次kubeadm init初始化操作失败了，该命令清理了之前的失败环境。
执行过程：
[root@k8s-master xcbeyond]# kubeadm init --config=kubeadm-config.yml | tee kubeadm-init.log[init] Using Kubernetes version: v1.20.0[preflight] Running pre-flight checks[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.default.svc.cluster.local] and IPs [10.96.0.1 192.168.11.100][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 [192.168.11.100 127.0.0.1 ::1][certs] Generating "etcd/peer" certificate and key[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.11.100 127.0.0.1 ::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". This can take up to 4m0s[apiclient] All control plane components are healthy after 28.009413 seconds[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace[kubelet] Creating a ConfigMap "kubelet-config-1.20" 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=''" and "node-role.kubernetes.io/control-plane='' (deprecated)"[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: abcdef.0123456789abcdef[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
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 192.168.11.100:6443 --token abcdef.0123456789abcdef \ --discovery-token-ca-cert-hash sha256:79f34a5872b3df5817d29330ec055d14509a66c96c5de01bfa0d640fab671d90复制代码
4.2.3 加入主节点
在 Master 节点上kubeadm init执行成功后，注意日志末尾的提示，按要求在 Master、Node 节点上执行相关命令即可。
kubeadm init初始化执行日志如下：
……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 192.168.11.100:6443 --token abcdef.0123456789abcdef \ --discovery-token-ca-cert-hash sha256:79f34a5872b3df5817d29330ec055d14509a66c96c5de01bfa0d640fab671d90复制代码
要使得非 root 用户可以运行kubectl，请运行以下命令（是 kubeadm init 输出日志的部分内容）：
mkdir -p $HOME/.kubesudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/configsudo chown $(id -u):$(id -g) $HOME/.kube/config复制代码
或者，如果你是 root 用户，则可以运行：
export KUBECONFIG=/etc/kubernetes/admin.conf复制代码
4.2.4 加入工作节点
工作节点是你的工作负载（容器和 Pod 等）运行的地方。要将新节点添加到集群，请对每台工作节点执行以下操作。
root 用户执行kubeadm init输出的命令：
kubeadm join 192.168.11.100:6443 --token abcdef.0123456789abcdef \ --discovery-token-ca-cert-hash sha256:79f34a5872b3df5817d29330ec055d14509a66c96c5de01bfa0d640fab671d90复制代码
执行过程：
[root@k8s-node01 xcbeyond]# kubeadm join 192.168.11.100:6443 --token abcdef.0123456789abcdef \> --discovery-token-ca-cert-hash sha256:79f34a5872b3df5817d29330ec055d14509a66c96c5de01bfa0d640fab671d90[preflight] Running pre-flight checks[preflight] Reading configuration from the cluster...[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'[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.复制代码
4.2.5 安装 Pod 网络附加插件
至此，在 Master 节点执行kubectl get nodes命令：
[root@k8s-master xcbeyond]# kubectl get nodesNAME STATUS ROLES AGE VERSIONk8s-master NotReady control-plane,master 1m8s v1.20.2k8s-node01 NotReady <none> 18s v1.20.2复制代码
发现是NotReady状态，因为 Kubernetes 要求必须要存在一个网络，即：目前还没有构建 Pod 网络附加插件，此时需要安装 Pod 网络附加插件。
可直接使用官方提供的 kube-flannel.yml 文件，进行创建。
（1）下载官方提供的 kube-flannel.yml 文件。
文件地址：https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml
（2）创建网络。
[root@k8s-master xcbeyond]# kubectl create -f kube-flannel.yml podsecuritypolicy.policy/psp.flannel.unprivileged createdclusterrole.rbac.authorization.k8s.io/flannel createdclusterrolebinding.rbac.authorization.k8s.io/flannel createdserviceaccount/flannel createdconfigmap/kube-flannel-cfg createddaemonset.apps/kube-flannel-ds created复制代码
（3）查看 Pod。
如果 flannel 还未
Running状态，可稍等一会儿，等待构建成功。
[root@k8s-master xcbeyond]# kubectl get pod -n kube-systemNAME READY STATUS RESTARTS AGEcoredns-74ff55c5b-fr4jj 0/1 ContainerCreating 0 6m3scoredns-74ff55c5b-wcj2h 0/1 ContainerCreating 0 6m3setcd-k8s-master 1/1 Running 0 6m5skube-apiserver-k8s-master 1/1 Running 0 6m5skube-controller-manager-k8s-master 1/1 Running 0 6m5skube-flannel-ds-2nkcv 1/1 Running 0 13skube-flannel-ds-m8tf2 1/1 Running 0 13skube-proxy-mft9t 0/1 CrashLoopBackOff 6 6m3skube-proxy-n67px 0/1 CrashLoopBackOff 3 68skube-scheduler-k8s-master 1/1 Running 0 6m5s复制代码
（4）查看节点状态。
此时已经Ready状态。
[root@k8s-master xcbeyond]# kubectl get nodesNAME STATUS ROLES AGE VERSIONk8s-master Ready control-plane,master 6m30s v1.20.2k8s-node01 Ready <none> 85s v1.20.2复制代码
4.3 集群环境验证
至此，基于kubeadm方式的集群搭建已完成，让我们一起在 Kubernetes 集群环境下开启 Kubernetes 的探索吧！
5、总结
安装过程中，可能会遇到各种形形色色的问题与障碍，大可不必担心，初次安装肯定会是这样的。
面对问题，有以下几点看法或建议：
遇到问题，说明你亲自动手过，这本身就是一种乐趣。（坑就是这么被踩出来的）
遇事不要慌，认真查看出错日志及提示。
根据关键错误信息，各种搜索齐上阵，尤其是在官方网站或 github。
解决问题后，要记录。
参考文章：
https://kubernetes.io/zh/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
https://www.cnblogs.com/nb-blog/p/10636733.html
https://www.cnblogs.com/shoufu/p/13047723.html
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发布于: 2021 年 02 月 04 日阅读数: 71
版权声明: 本文为 InfoQ 作者【xcbeyond】的原创文章。
原文链接:【http://xie.infoq.cn/article/592da7319e5f8a4e1351bd92d】。文章转载请联系作者。
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