Kubernetes&Docker集群部署

曾经那一抹阳光 發表於 2022-1-19 09:56:00

<h2 id="集群环境搭建">集群环境搭建</h2>
<p>搭建kubernetes的集群环境</p>
<h3 id="环境规划">环境规划</h3>
<h4 id="集群类型">集群类型</h4>
<p>kubernetes集群大体上分为两类：<strong>一主多从</strong>和<strong>多主多从</strong>。</p>
<ul>
<li>一主多从：一台Master节点和多台Node节点，搭建简单，但是有单机故障风险，适合用于测试环境</li>
<li>多主多从：多台Master节点和多台Node节点，搭建麻烦，安全性高，适合用于生产环境</li>
</ul>
<p><img src="https://gitee.com/HOSystem/learning-notes/raw/master/k8s/2%E3%80%81Kubernetes%E9%9B%86%E7%BE%A4%E9%83%A8%E7%BD%B2/assets/image-20220115001527682.png" alt="image-20220115001527682" loading="lazy"></p>
<h4 id="安装方式">安装方式</h4>
<p>kubernetes有多种部署方式，目前主流的方式有kubeadm、minikube、二进制包</p>
<ul>
<li>minikube：一个用于快速搭建单节点kubernetes的工具</li>
<li>kubeadm：一个用于快速搭建kubernetes集群的工具</li>
<li>二进制包：从官网下载每个组件的二进制包，依次去安装，此方式对于理解kubernetes组件更加有效</li>
</ul>
<h4 id="主机规划">主机规划</h4>
<p>这里推荐使用<code>Centos7.6.1810</code>的系统，其它系统可能会出现意想不到的问题。如使用<code>Centos7.3</code>的系统会出现 <code>网络同步Chronyd</code> 启动不成功问题，Centos7.x可以通过<code>yum update</code>来升级内核。</p>
<table>
<thead>
<tr>
<th>作用</th>
<th>IP地址</th>
<th>操作系统</th>
<th>配置</th>
</tr>
</thead>
<tbody>
<tr>
<td>k8s-Master</td>
<td>10.80.6.120</td>
<td>Centos7.6.1810</td>
<td>8H/8G 50G</td>
</tr>
<tr>
<td>k8s-Node1</td>
<td>10.80.6.121</td>
<td>Centos7.6.1810</td>
<td>8H/8G 50G</td>
</tr>
<tr>
<td>k8s-Node2</td>
<td>10.80.6.122</td>
<td>Centos7.6.1810</td>
<td>8H/8G 50G</td>
</tr>
</tbody>
</table>
<h3 id="环境搭建">环境搭建</h3>
<p>本次环境搭建需要安装四台Centos服务器（一主三从），然后在每台服务器中分别安装docker（19.03.5），kubeadm（1.18.8）、kubelet（1.18.8）、kubectl（1.18.8）程序。</p>
<p>可能通过kubectl查看版本时会变成1.18.20 并不影响使用。1.18.20一样也适配docker（19.03.5）</p>
<p>如果需要别的版本可以自行查询K8s和Docker版本的适配。</p>
<h4 id="主机安装">主机安装</h4>
<p>安装虚拟机过程中注意下面选项的设置：</p>
<ul>
<li>操作系统环境：CPU（2H）内存（8G）硬盘（30G）</li>
<li>语言选择：中文简体</li>
<li>软件选择：基础设施服务器</li>
<li>分区选择：自动分区</li>
<li>网络配置：按照下面配置网路地址信息</li>
</ul>
<pre><code class="language-shell"># 要查看自己本机的 IP地址(IPADDR)、掩码地址(NETMASK)、网关(GATEWAY)、DNS地址然后填上去
$ vi /etc/sysconfig/network-scripts/ifcfg-ensxxx
BOOTPROTO=static
ONBOOT=yes
IPADDR=10.80.6.120
NETWASK=255.255.0.0
GATEWAY=10.80.6.1
DNS1=114.114.114.114
DNS2=10.80.6.1
DNS3=8.8.8.8
</code></pre>
<ul>
<li>主机名设置：按照下面信息设置主机名</li>
</ul>
<pre><code class="language-shell">master$ hostnamectl set-hostname k8s-master #master节点: k8s-master
node1$ hostnamectl set-hostname k8s-node1 #node1节点: k8s-node1
node2$ hostnamectl set-hostname k8s-node2 #node2节点: k8s-node2
</code></pre>
<h4 id="环境初始化">环境初始化</h4>
<ul>
<li>更换镜像源</li>
</ul>
<pre><code class="language-shell">#创建sh脚本,将以下内容粘贴到reposintall.sh里
$ vi reposinstall.sh
#!/bin/bash
cd /etc/yum.repos.d/
mkdir repo_bak
mv *.repo repo_bak/
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
yum makecache
yum install -y epel-release.noarch
yum clean all
yum makecache
yum repolist all

$ sh reposinstall.sh
.......
</code></pre>
<ul>
<li>检查操作系统的版本</li>
</ul>
<pre><code class="language-shell"># 此方式下安装kubernetes集群要求Centos版本要在7.5或之上
$ cat /etc/redhat-release
CentOS Linux release 7.6.1810 (Core)

# 若Centos版本不在7.5或之上通过yum更新
$ yum update
</code></pre>
<ul>
<li>主机名解析</li>
</ul>
<p>为了方便后面集群节点间的直接调用，在这配置一下主机名解析，企业中推荐使用内部DNS服务器。</p>
<pre><code class="language-shell"># 主机名成解析编辑四台服务器的/etc/hosts文件，添加下面内容
# 注意：主机名不能带下划线，只能带中划线
$ vi /etc/hosts
10.80.6.120 k8s-master
10.80.6.121 k8s-node1
10.80.6.122 k8s-node2
</code></pre>
<ul>
<li>时间同步（待定检测必要性）</li>
</ul>
<p>kubernetes要求集群中的节点时间必须精确一致，这里直接使用chronyd服务从网络同步时间；也可以使用<code>网络授时NTP</code>。</p>
<p>企业中建议配置内部的时间同步服务器。</p>
<pre><code class="language-shell">#若chrony不存在,使用yum安装
$ yum install -y chrony

# 启动chronyd服务若启动出现错误查看问题汇总中问题10
$ systemctl start chronyd
# 设置chronyd服务开机自启
$ systemctl enable chronyd
# chronyd服务启动稍等几秒钟，就可以使用date命令验证时间了
$ date
</code></pre>
<ul>
<li>禁用iptables和firewalld服务</li>
</ul>
<p>kubernetes和docker在运行中会产生大量的iptables规则，为了不让系统规则跟它们混淆，直接关闭系统的规则。</p>
<pre><code class="language-shell"># 1 关闭firewalld服务
$ systemctl stop firewalld
$ systemctl disable firewalld
# 2 关闭iptables服务
$ systemctl stop iptables
$ systemctl disable iptables
</code></pre>
<ul>
<li>禁用selinux</li>
</ul>
<p>selinux是linux系统下的一个安全服务，如果不关闭它，在安装集群中会产生各种各样的奇葩问题。</p>
<pre><code class="language-shell"># 编辑 /etc/selinux/config 文件，修改SELINUX的值为disabled
# 注意修改完毕之后需要重启linux服务
$ vi /etc/selinux/config
SELINUX=disabled
</code></pre>
<ul>
<li>禁用swap分区</li>
</ul>
<p>swap分区指的是虚拟内存分区，它的作用是在物理内存使用完之后，将磁盘空间虚拟成内存来使用。</p>
<p>启用swap设备会对系统的性能产生非常负面的影响，因此kubernetes要求每个节点都要禁用swap设备。</p>
<p>但是如果因为某些原因确实不能关闭swap分区，就需要在集群安装过程中通过明确的参数进行配置说明。</p>
<pre><code class="language-shell"># 编辑分区配置文件/etc/fstab，注释掉有 `swap`分区字样的一行
# 注意修改完毕之后需要重启linux服务
$ vi /etc/fstab
# /dev/mapper/centos-swap swap                   swap defaults    0 0
</code></pre>
<ul>
<li>修改linux的内核参数</li>
</ul>
<pre><code class="language-shell"># 修改linux的内核参数，添加网桥过滤和地址转发功能
# 出现Can't open file for writing查看问题九
# 编辑/etc/sysctl.d/kubernetes.conf文件，添加如下配置:
$ sudo vi /ect/sysctl.d/kubernetes.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1

# 重新加载配置
$ sysctl -p

# 加载网桥过滤模块
$ modprobe br_netfilter

# 查看网桥过滤模块是否加载成功
$ lsmod | grep br_netfilter
</code></pre>
<p><img src="https://gitee.com/HOSystem/learning-notes/raw/master/k8s/2%E3%80%81Kubernetes%E9%9B%86%E7%BE%A4%E9%83%A8%E7%BD%B2/assets/image-20220118143005305.png" alt="image-20220118143005305" loading="lazy"></p>
<ul>
<li>配置ipvs功能</li>
</ul>
<p>在kubernetes中service有两种代理模型，一种是基于iptables的，一种是基于ipvs的。</p>
<p>两者比较的话，ipvs的性能明显要高一些，但是如果要使用它，需要手动载入ipvs模块。</p>
<pre><code class="language-shell"># 1 安装ipset和ipvsadm
$ yum install ipset ipvsadm -y

# 2 添加需要加载的模块写入脚本文件
$ cat <<EOF >/etc/sysconfig/modules/ipvs.modules
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF

# 3 为脚本文件添加执行权限
$ chmod +x /etc/sysconfig/modules/ipvs.modules

# 4 执行脚本文件
$ /bin/bash /etc/sysconfig/modules/ipvs.modules

# 5 查看对应的模块是否加载成功
$ lsmod | grep -e ip_vs -e nf_conntrack_ipv4
</code></pre>
<p><img src="https://gitee.com/HOSystem/learning-notes/raw/master/k8s/2%E3%80%81Kubernetes%E9%9B%86%E7%BE%A4%E9%83%A8%E7%BD%B2/assets/image-20220118123654547.png" alt="image-20220118123654547" loading="lazy"></p>
<ul>
<li>重启服务器</li>
</ul>
<p>上面步骤完成之后，需要重新启动linux系统。</p>
<pre><code class="language-shell">$ reboot
</code></pre>
<h4 id="安装docker">安装docker</h4>
<pre><code class="language-shell"># 1 切换镜像源
$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo

# 2 查看当前镜像源中支持的docker版本
$ yum list docker-ce --showduplicates

# 3 安装特定版本的docker-ce
# 必须指定--setopt=obsoletes=0，否则yum会自动安装更高版本
# 安装其它版本号版本号可通过 yum list docker-ce --showduplicates查看
# 如果想安装其它版本一定要docker-ce-xxx 和 docker-ce-cli-xxx containerd.io 这三个一个都不能缺少
$ yum install --setopt=obsoletes=0 docker-ce-19.03.5 docker-ce-cli-19.03.5 containerd.io -y

# 4 添加一个配置文件
# Docker在默认情况下使用的Cgroup Driver为cgroupfs，而kubernetes推荐使用systemd来代替cgroupfs
$ mkdir /etc/docker
$ cat <<EOF >/etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"registry-mirrors": ["https://kn0t2bca.mirror.aliyuncs.com"]
}
EOF

# 5 启动docker
$ systemctl restart docker
$ systemctl enable docker

# 6 检查docker状态和版本
$ docker --version
Docker version 19.03.5, build 633a0ea

# 7 查看镜像加速是否成功
# 出现xxx.alixxx就成功
$ docker info
Registry Mirrors:
https://xxx.mirror.aliyuncs.com
</code></pre>
<h4 id="安装kubernetes组件">安装kubernetes组件</h4>
<pre><code class="language-shell"># 由于kubernetes的镜像源在国外，速度比较慢，这里切换成国内的镜像源
# 1.编辑/etc/yum.repos.d/kubernetes.repo，添加下面的配置
$ vi /etc/yum.repos.d/kubernetes.repo

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

# 2.查看当前镜像源中支持的docker版本
# 也可通过 http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/Packages/ 查看版本信息
$ yum list kubectl --showduplicates

# 3.安装kubeadm、kubelet和kubectl
# kubernetes1.18.8和docker19.03.5适配
$ yum install --setopt=obsoletes=0 kubeadm-1.18.8-0 kubelet-1.18.8-0 kubectl-1.18.8-0 -y

# 配置kubelet的cgroup
# 4.编辑/etc/sysconfig/kubelet，添加下面的配置
$ vi /etc/sysconfig/kubelet
KUBELET_CGROUP_ARGS="--cgroup-driver=systemd"
KUBE_PROXY_MODE="ipvs"

# 5.设置kubelet开机自启
$ systemctl enable kubelet
</code></pre>
<h4 id="准备集群镜像">准备集群镜像</h4>
<pre><code class="language-shell"># 在安装kubernetes集群之前，必须要提前准备好集群需要的镜像，所需镜像可以通过下面命令查看
$ kubeadm config images list
k8s.gcr.io/kube-apiserver:v1.18.20
k8s.gcr.io/kube-controller-manager:v1.18.20
k8s.gcr.io/kube-scheduler:v1.18.20
k8s.gcr.io/kube-proxy:v1.18.20
k8s.gcr.io/pause:3.2
k8s.gcr.io/etcd:3.4.3-0
k8s.gcr.io/coredns:1.6.7

# 下载镜像
# 此镜像在kubernetes的仓库中,由于网络原因,无法连接，下面提供了一种替代方案
$ images=(
kube-apiserver:v1.18.20
kube-controller-manager:v1.18.20
kube-scheduler:v1.18.20
kube-proxy:v1.18.20
pause:3.2
etcd:3.4.3-0
coredns:1.6.7
)

$ for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName k8s.gcr.io/$imageName
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/$imageName
done
</code></pre>
<h4 id="集群初始化">集群初始化</h4>
<p>下面开始对集群进行初始化，并将node节点加入到集群中</p>
<blockquote>
<p>下面的操作只需要在<code>master</code>节点上执行即可</p>
</blockquote>
<pre><code class="language-shell">#1.查看kubectl 版本信息
$ kubectl version

# apiserver-advertise-address 为k8s-master的ip地址
# image-repository 由于默认拉取镜像地址k8s.gcr.io国内无法访问，这里指定阿里云镜像仓库地址。
# 该操作可能会等待时间较长可通过docker images 查看镜像的pull 大致了解镜像拉取情况
# 出现 Kubernetes control-plane has initialized successfully! 才算成功
# 若出现错误,则查看问题汇总
# 将--apiserver-advertise-address=192.168.188.128 使用 --apiserver-advertise-address=$(ip addr|grep ens|awk '{print $2}'|grep '/'| head -c-4)替代
#2.创建集群
$ kubeadm init \
--kubernetes-version=v1.18.20 \
--pod-network-cidr=10.244.0.0/16 \
--service-cidr=10.96.0.0/12 \
--apiserver-advertise-address=本机的IP地址
#参数说明
--kubernetes-version=v1.18.20: kubernetes版本可通过kubectl version 查看版本信息
--pod-network-cidr=10.244.0.0/16: pod网关可默认
--service-cidr=10.96.0.0/12: server网络可默认
--apiserver-advertise-address=10.80.6.120: master的ip地址

.....
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 .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 10.80.6.120:6443 --token 8xfehq.bbghn94cpaowmnjb \
--discovery-token-ca-cert-hash sha256:e51a57f9e4f0205c646a81a0cef402b11ec2f1a82c6ea5a5f0cac8c0a9f5b9c1
</code></pre>
<p>使用kubectl工具：</p>
<pre><code class="language-shell"># 这一段为上面 Your Kubernetes control-plane has initialized successfully! 后面的内容
#3.创建必要文件
$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config

#4.获取节点信息
$ kubectl get nodes
NAME       STATUS ROLES AGE VERSION
k8s-master Ready master 13h v1.18.8
</code></pre>
<blockquote>
<p>下面的操作只需要在<code>node</code>节点上执行即可</p>
</blockquote>
<pre><code class="language-shell"># 将node节点加入集群
$ kubeadm join 10.80.6.120:6443 --token 8xfehq.bbghn94cpaowmnjb \
--discovery-token-ca-cert-hash sha256:e51a57f9e4f0205c646a81a0cef402b11ec2f1a82c6ea5a5f0cac8c0a9f5b9c1

# 查看集群状态此时的集群状态为NotReady，这是因为还没有配置网络插件
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 13h v1.18.8
k8s-node1 Ready <none> 13h v1.18.8
k8s-node2 Ready <none> 13h v1.18.8
</code></pre>
<h4 id="安装网络插件">安装网络插件</h4>
<p>kubernetes支持多种网络插件，比如flannel、calico、canal等等，任选一种使用即可，本次选择flannel。</p>
<p>这一步操作是将<code>kubectl get nodes</code>中<code>noteady</code>状态变为<code>ready</code>状态的过程。</p>
<blockquote>
<p>下面操作依旧只在<code>master</code>节点执行即可，插件使用的是DaemonSet的控制器，它会在每个节点上都运行</p>
</blockquote>
<p>这里存在两种方式，<code>方式一</code>和<code>方式二</code>，若kube-flannel.yml下载失败，可通过复制<code>kube-flannel.yml</code>并在linux中创建粘贴即可。</p>
<p>方式一：</p>
<pre><code class="language-shell"># 获取fannel的配置文件
# 修改文件中quay.io仓库为quay-mirror.qiniu.com
# 这里有时候会下载失败
$ wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
或
$ vi kube-fannel.yml #kube-flannel.yml文件在下面已经给出

# 使用配置文件启动fannel
$ kubectl apply -f kube-flannel.yml

# 稍等片刻，再次查看集群节点的状态
# 可能需要等待的时间较长,请耐心等待。也可通过切换到notready 节点中使用docker ps 查看镜像启动信息
# 若很长时间都是notready可通过kubectl查看日志
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 13h v1.18.8
k8s-node1 Ready <none> 13h v1.18.8
k8s-node2 Ready <none> 13h v1.18.8
</code></pre>
<ul>
<li><code>kube-flannel.yml</code>文件</li>
</ul>
<pre><code class="language-yaml">---
kind: Namespace
apiVersion: v1
metadata:
name: kube-flannel
labels:
pod-security.kubernetes.io/enforce: privileged
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: flannel
rules:
- apiGroups:
- ""
resources:
- pods
verbs:
- get
- apiGroups:
- ""
resources:
- nodes
verbs:
- list
- watch
- apiGroups:
- ""
resources:
- nodes/status
verbs:
- patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: flannel
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: flannel
subjects:
- kind: ServiceAccount
name: flannel
namespace: kube-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: flannel
namespace: kube-flannel
---
kind: ConfigMap
apiVersion: v1
metadata:
name: kube-flannel-cfg
namespace: kube-flannel
labels:
tier: node
app: flannel
data:
cni-conf.json: |
{
   "name": "cbr0",
   "cniVersion": "0.3.1",
   "plugins": [
   {
      "type": "flannel",
      "delegate": {
         "hairpinMode": true,
         "isDefaultGateway": true
      }
   },
   {
      "type": "portmap",
      "capabilities": {
         "portMappings": true
      }
   }
   ]
}
net-conf.json: |
{
   "Network": "10.244.0.0/16",
   "Backend": {
   "Type": "vxlan"
   }
}
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-flannel-ds
namespace: kube-flannel
labels:
tier: node
app: flannel
spec:
selector:
matchLabels:
   app: flannel
template:
metadata:
   labels:
   tier: node
   app: flannel
spec:
   affinity:
   nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
         nodeSelectorTerms:
         - matchExpressions:
         - key: kubernetes.io/os
            operator: In
            values:
            - linux
   hostNetwork: true
   priorityClassName: system-node-critical
   tolerations:
   - operator: Exists
   effect: NoSchedule
   serviceAccountName: flannel
   initContainers:
   - name: install-cni-plugin
   #image: flannelcni/flannel-cni-plugin:v1.1.0 for ppc64le and mips64le (dockerhub limitations may apply)
   image: docker.io/rancher/mirrored-flannelcni-flannel-cni-plugin:v1.1.0
   command:
   - cp
   args:
   - -f
   - /flannel
   - /opt/cni/bin/flannel
   volumeMounts:
   - name: cni-plugin
      mountPath: /opt/cni/bin
   - name: install-cni
   #image: flannelcni/flannel:v0.20.1 for ppc64le and mips64le (dockerhub limitations may apply)
   image: docker.io/rancher/mirrored-flannelcni-flannel:v0.20.1
   command:
   - cp
   args:
   - -f
   - /etc/kube-flannel/cni-conf.json
   - /etc/cni/net.d/10-flannel.conflist
   volumeMounts:
   - name: cni
      mountPath: /etc/cni/net.d
   - name: flannel-cfg
      mountPath: /etc/kube-flannel/
   containers:
   - name: kube-flannel
   #image: flannelcni/flannel:v0.20.1 for ppc64le and mips64le (dockerhub limitations may apply)
   image: docker.io/rancher/mirrored-flannelcni-flannel:v0.20.1
   command:
   - /opt/bin/flanneld
   args:
   - --ip-masq
   - --kube-subnet-mgr
   resources:
      requests:
         cpu: "100m"
         memory: "50Mi"
      limits:
         cpu: "100m"
         memory: "50Mi"
   securityContext:
      privileged: false
      capabilities:
         add: ["NET_ADMIN", "NET_RAW"]
   env:
   - name: POD_NAME
      valueFrom:
         fieldRef:
         fieldPath: metadata.name
   - name: POD_NAMESPACE
      valueFrom:
         fieldRef:
         fieldPath: metadata.namespace
   - name: EVENT_QUEUE_DEPTH
      value: "5000"
   volumeMounts:
   - name: run
      mountPath: /run/flannel
   - name: flannel-cfg
      mountPath: /etc/kube-flannel/
   - name: xtables-lock
      mountPath: /run/xtables.lock
   volumes:
   - name: run
   hostPath:
      path: /run/flannel
   - name: cni-plugin
   hostPath:
      path: /opt/cni/bin
   - name: cni
   hostPath:
      path: /etc/cni/net.d
   - name: flannel-cfg
   configMap:
      name: kube-flannel-cfg
   - name: xtables-lock
   hostPath:
      path: /run/xtables.lock
      type: FileOrCreate
</code></pre>
<p>方式二：</p>
<pre><code class="language-shell">$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

# 稍等片刻，再次查看集群节点的状态
# 可能需要等待的时间较长,请耐心等待。也可通过切换到notready 节点中使用docker ps 查看镜像启动信息
# 若很长时间都是notready可通过kubectl查看日志
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 13h v1.18.8
k8s-node1 Ready <none> 13h v1.18.8
k8s-node2 Ready <none> 13h v1.18.8
</code></pre>
<p>至此，kubernetes的集群环境搭建完成。</p>
<h3 id="服务部署">服务部署</h3>
<p>所有操作都是通过master节点操作，而不需要到node节点上操作。</p>
<pre><code class="language-shell"># 部署nginx
$ kubectl create deployment nginx --image=nginx:1.14-alpine
deployment.apps/nginx created

# 暴露端口
$ kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed

# 查看服务状态
$ kubectl get pods,service
NAME                      READY STATUS RESTARTS AGE
pod/nginx-55f8fd7cfc-wvdxq 1/1 Running 0       30m

NAME             TYPE    CLUSTER-IP EXTERNAL-IP PORT(S)    AGE
service/kubernetes ClusterIP 10.96.0.1    <none>    443/TCP    35m
service/nginx    NodePort 10.107.52.75 <none>    80:30983/TCP 30m

# 4 最后在电脑上访问下部署的nginx服务
</code></pre>
<p><img src="https://gitee.com/HOSystem/learning-notes/raw/master/k8s/2%E3%80%81Kubernetes%E9%9B%86%E7%BE%A4%E9%83%A8%E7%BD%B2/assets/image-20220118202200835.png" alt="image-20220118202200835" loading="lazy"></p>
<h2 id="问题汇总">问题汇总</h2>
<h3 id="问题一">问题一：</h3>
<p><strong>问题描述：</strong></p>
<p>在K8S-Master中执行 <code>kubeadm init...</code>出现以下错误</p>
<pre><code class="language-markdown">W0112 22:25:15.385511 18569 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups
Using Kubernetes version: v1.18.0
Running pre-flight checks
: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
error execution phase preflight: Some fatal errors occurred:
: running with swap on is not supported. Please disable swap
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
</code></pre>
<p><strong>问题原因：</strong></p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell">#1.修改docker.service
$ vi /usr/lib/systemd/system/docker.service
#修改成如下内容
ExecStart=/usr/bin/dockerd --exec-opt native.cgroupdriver=systemd

#2.重启docker
$ systemctl daemon-reload && systemctl restart docker
</code></pre>
<h3 id="问题二">问题二：</h3>
<p><strong>问题描述：</strong></p>
<p>在K8S-Master中执行 <code>kubeadm init...</code>出现以下错误</p>
<pre><code class="language-markdown">W0112 22:28:21.715514 18853 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups
Using Kubernetes version: v1.18.0
Running pre-flight checks
error execution phase preflight: Some fatal errors occurred:
: running with swap on is not supported. Please disable swap
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
</code></pre>
<p><strong>问题原因：</strong></p>
<p>running with swap on is not supported. Please disable swap 关闭swap;</p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell">$ sed -ri 's/.*swap.*/#&/' /etc/fstab
</code></pre>
<h3 id="问题三">问题三：</h3>
<p><strong>问题描述：</strong></p>
<p><code> for imageName in ${images[@]} ; do</code>安装kubernetes镜像时，docker出现卡住的现象。出现以下问题</p>
<pre><code class="language-shell">597de8ba0c30: Already exists
3f0663684f29: Pull complete
e1f7f878905c: Pull complete
3029977cf65d: Pulling fs layer
</code></pre>
<p><strong>问题原因：</strong></p>
<p>可能时网络问题，可能时其它原因。</p>
<p><strong>问题解决：</strong></p>
<ul>
<li>重启docker</li>
</ul>
<pre><code class="language-shell">$ systemctl restart docker
</code></pre>
<ul>
<li>删除docker的缓存；docker拉取的的镜像是存放在/var/lib/docker/overlay2，缓存是在/var/lib/docker/tmp，但是我都删掉反而报错有其中有的东西不能删；</li>
</ul>
<pre><code class="language-shell">//TODO 待定
</code></pre>
<h3 id="问题四">问题四：</h3>
<p><strong>问题描述：</strong></p>
<p>在master执行<code>kubeadm init --kubernetes-version=xxx..</code>命令后,出现以下错误</p>
<pre><code class="language-shell">Unable to connect to the server: x509: certificate signed by unknown authority
</code></pre>
<p><strong>问题原因：</strong></p>
<p>删除集群然后重新创建也算是一个常规的操作，如果你在执行 <code>kubeadm reset</code>命令后没有删除创建的 <code>$HOME/.kube</code>目录，重新创建集群就会出现这个问题！</p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell"># 在执行这几个命令前先执行rm -rf $HOME/.kube命令删除这个目录
$ mkdir -p $HOME/.kube
$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
</code></pre>
<h3 id="问题五">问题五：</h3>
<p><strong>问题描述：</strong></p>
<p>在子节点执行kubeadm join命令后返回 <code>error uploading crisocket: timed out waiting for the condition</code></p>
<pre><code class="language-markdown"> The HTTP call equal to 'curl -sSL http://localhost:10248/healthz' failed with error: Get http://localhost:10248/healthz: dial tcp [::1]:10248: connect: connection refused.

error execution phase kubelet-start: error uploading crisocket: timed out waiting for the condition
To see the stack trace of this error execute with --v=5 or higher
</code></pre>
<p><strong>问题原因：</strong></p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell">$ swapoff -a
$ kubeadm reset
$ systemctl daemon-reload
$ systemctl restart kubelet
$ iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
</code></pre>
<p>以上执行完成后再执行加入子结点的操作：</p>
<pre><code>kubeadm join 10.80.6.120:6443 --token f4ls6h.ogl776zklkoeqei9 \
--discovery-token-ca-cert-hash sha256:96ec68a8116024da03a763c0af61fbd933615d93949d9c3b01c952af0193f149
</code></pre>
<h3 id="问题六">问题六：</h3>
<p><strong>问题描述：</strong></p>
<p>在子节点执行kubeadm join命令后返回 <code>/etc/kubernetes/kubelet.conf already exists</code>等问题。</p>
<pre><code class="language-markdown">error execution phase preflight: Some fatal errors occurred:
: /etc/kubernetes/kubelet.conf already exists
: /etc/kubernetes/pki/ca.crt already exists
</code></pre>
<p><strong>问题原因：</strong></p>
<p>原来旧的配置文件都存在了，所以无法kubeadm join到master中。</p>
<p><strong>问题解决：</strong></p>
<p>把<code>/etc/kubernetes/kubelet.conf</code>和<code>/etc/kubernetes/pki/ca.crt</code>删除即可</p>
<pre><code class="language-shell">$ rm -f /etc/kubernetes/kubelet.conf /etc/kubernetes/pki/ca.crt
</code></pre>
<h3 id="问题七">问题七：</h3>
<p><strong>问题描述：</strong></p>
<p>安装k8s时出现以下错误，</p>
<pre><code class="language-shell">could not convert cfg to an internal cfg: nodeRegistration.name: Invalid value: "k8s_master": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '([-a-z0-9]*)?(\.([-a-z0-9]*)?)*')
</code></pre>
<p><strong>问题原因：</strong></p>
<p>这是因为主机名不能带下划线，只能带中划线。</p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell">将主机名的下划线`_` 改为中划线`-` 即可
</code></pre>
<h3 id="问题八">问题八：</h3>
<p><strong>问题描述：</strong></p>
<p>修改linux的内核参数时，保存<code>/etc/sysctl.d/kubernetes.conf</code>文件时，出现<code>Can't open file for writing</code>错误</p>
<p><img src="https://gitee.com/HOSystem/learning-notes/raw/master/k8s/2%E3%80%81Kubernetes%E9%9B%86%E7%BE%A4%E9%83%A8%E7%BD%B2/assets/image-20220118181145091.png" alt="image-20220118181145091" loading="lazy"></p>
<p><strong>问题原因：</strong></p>
<p>可能一个原因是权限不够，使用root解决</p>
<p><strong>问题解决：</strong></p>
<pre><code class="language-shell">$ su root
$ vi /etc/sysctl.d/kubernetes.conf
</code></pre>
<h3 id="问题九">问题九：</h3>
<p><strong>问题描述：</strong></p>
<p>通过<code>yum -y install chrony</code>后，使用<code>systemctl start chronyd</code>时出现<code>Job for chronyd.service failed because the control process exited with error code. See "systemctl status chronyd.service" and "journalctl -xe" for details.</code></p>
<p><strong>问题原因：</strong></p>
<p>使用yum -y install chrony命令，自动安装了最新版的chrony服务（配套7.7内核）。由于我的系统是7.3，可能不兼容高版本的chrony服务，导致服务启动失败。（个人理解猜测）</p>
<p><strong>问题解决：</strong></p>
<ul>
<li>使用yum -y update。将系统版本升级至最新即可解决。（我使用的此方法）</li>
<li>使用CentOS 7.3 yum源，安装兼容7.3的Chrony版本。</li>
</ul>
<h3 id="问题十">问题十：</h3>
<p><strong>问题描述：</strong></p>
<p>使用wget下载东西时，出现<code>-bash: wget: command not found</code>错误</p>
<p><strong>问题原因：</strong></p>
<p>wget没有安装</p>
<p><strong>问题解决：</strong></p>
<p>通过yum安装wget</p>
<pre><code class="language-shell">$ yum install -y wget
</code></pre>
<h2 id="参考文档">参考文档</h2>
<p>中文官网 - 点我传送</p>
<p>中文社区 - 点我传送</p>
<p>docker-repos-Aliyun - 点我传送</p>
<p>Centos7安装Docker&镜像加速 - 点我传送</p>
<p>kubernetes-repos-Aliyun - 点我传送</p>
<p>K8Schangelog - 点我传送</p><br><br>
来源：https://www.cnblogs.com/HOsystem/p/15821022.html

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