使用kubeadm部署Kubernetes 1.24

发布于 2022-08-05  256 次阅读


1. 前期准备

  1. 服务器环境为:Ubuntu server LTS 18.04
  2. 主机有三台:
192.168.30.128 vm-test-01
192.168.30.129 vm-test-02
192.168.30.130 vm-test-03

在各个主机上完成下面的系统配置。

如果各个主机启用了防火墙策略,需要开放Kubernetes各个组件所需要的端口,可以查看Ports and Protocols中的内容, 开放相关端口或者关闭主机的防火墙。

注:CENTOS系统需要额外注释掉Selinux

禁用Selinux

临时
setenforce 0
永久有效
vi /etc/selinux/config
SELINUX=disabled

创建/etc/modules-load.d/containerd.conf配置文件:

cat << EOF > /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF

执行以下命令使配置生效:

modprobe overlay
modprobe br_netfilter

创建/etc/sysctl.d/99-kubernetes-cri.conf配置文件:

cat << EOF > /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
user.max_user_namespaces=28633
EOF

执行以下命令使配置生效:

sysctl -p /etc/sysctl.d/99-kubernetes-cri.conf

1.2 配置服务器支持开启ipvs的前提条件

由于ipvs已经加入到了内核的主干,所以为kube-proxy开启ipvs的前提需要加载以下的内核模块:

ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4

在各个服务器节点上执行以下脚本:

mkdir /etc/sysctl.d/modules
cat > /etc/sysctl.d/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
chmod 755 /etc/sysctl.d/modules/ipvs.modules && bash /etc/sysctl.d/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

上面脚本创建了的/etc/sysctl.d/modules/ipvs.modules文件,保证在节点重启后能自动加载所需模块。 使用lsmod | grep -e ip_vs -e nf_conntrack_ipv4命令查看是否已经正确加载所需的内核模块。

接下来还需要确保各个节点上已经安装了ipset软件包,为了便于查看ipvs的代理规则,最好安装一下管理工具ipvsadm。

apt install ipvsadm ipset

如果不满足以上前提条件,则即使kube-proxy的配置开启了ipvs模式,也会退回到iptables模式。

1.3 部署容器运行时Containerd

在各个服务器节点上安装容器运行时Containerd。

下载Containerd的二进制包:

wget https://github.com/containerd/containerd/releases/download/v1.6.4/cri-containerd-cni-1.6.4-linux-amd64.tar.gz

cri-containerd-cni-1.6.4-linux-amd64.tar.gz压缩包中已经按照官方二进制部署推荐的目录结构布局好。 里面包含了systemd配置文件,containerd以及cni的部署文件。 将解压缩到系统的根目录/中:

tar -zxvf cri-containerd-cni-1.6.4-linux-amd64.tar.gz -C /

etc/
etc/systemd/
etc/systemd/system/
etc/systemd/system/containerd.service
etc/crictl.yaml
etc/cni/
etc/cni/net.d/
etc/cni/net.d/10-containerd-net.conflist
usr/
usr/local/
usr/local/sbin/
usr/local/sbin/runc
usr/local/bin/
usr/local/bin/critest
usr/local/bin/containerd-shim
usr/local/bin/containerd-shim-runc-v1
usr/local/bin/ctd-decoder
usr/local/bin/containerd
usr/local/bin/containerd-shim-runc-v2
usr/local/bin/containerd-stress
usr/local/bin/ctr
usr/local/bin/crictl
......
opt/cni/
opt/cni/bin/
opt/cni/bin/bridge
......

意经测试cri-containerd-cni-1.6.4-linux-amd64.tar.gz包中包含的runc在CentOS 7下的动态链接有问题,这里从runc的github上单独下载runc,并替换上面安装的containerd中的runc:

wget https://github.com/opencontainers/runc/releases/download/v1.1.2/runc.amd64
cp runc.amd64 /usr/local/sbin/runc
在给个执行权限
chmod +x runc

接下来生成containerd的配置文件:

mkdir -p /etc/containerd
containerd config default > /etc/containerd/config.toml

根据文档Container runtimes 中的内容,对于使用systemd作为init system的Linux的发行版,使用systemd作为容器的cgroup driver可以确保服务器节点在资源紧张的情况更加稳定,因此这里配置各个节点上containerd的cgroup driver为systemd。

修改前面生成的配置文件/etc/containerd/config.toml

[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
  ...
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
  ...
    SystemdCgroup = true

再修改/etc/containerd/config.toml中的

[plugins."io.containerd.grpc.v1.cri"]
  ...
  # sandbox_image = "k8s.gcr.io/pause:3.6"
  sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.7"

配置containerd开机启动,并启动containerd

systemctl enable containerd --now

使用crictl测试一下,确保可以打印出版本信息并且没有错误信息输出:

crictl version
Version:  0.1.0
RuntimeName:  containerd
RuntimeVersion:  v1.6.4
RuntimeApiVersion:  v1alpha2

2.使用kubeadm部署Kubernetes

2.1 安装kubeadm和kubelet

下面在各节点安装kubeadm和kubelet:

cat <<EOF >> /etc/apt/sources.list
# kubeadm及kubernetes组件安装源
deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl

运行kubelet --help可以看到原来kubelet的绝大多数命令行flag参数都被DEPRECATED了,官方推荐我们使用--config指定配置文件,并在配置文件中指定原来这些flag所配置的内容。具体内容可以查看这里Set Kubelet parameters via a config file最初Kubernetes这么做是为了支持动态Kubelet配置(Dynamic Kubelet Configuration),但动态Kubelet配置特性从k8s 1.22中已弃用,并在1.24中被移除。如果需要调整集群汇总所有节点kubelet的配置,还是推荐使用ansible等工具将配置分发到各个节点

kubelet的配置文件必须是json或yaml格式,具体可查看这里

Kubernetes 1.8开始要求关闭系统的Swap,如果不关闭,默认配置下kubelet将无法启动。 关闭系统的Swap方法如下:

swapoff -a

修改 /etc/fstab 文件,注释掉 SWAP 的自动挂载,使用free -m确认swap已经关闭。

swappiness参数调整,修改/etc/sysctl.d/99-kubernetes-cri.conf添加下面一行:

vm.swappiness=0

执行sysctl -p /etc/sysctl.d/99-kubernetes-cri.conf使修改生效。

2.2 使用kubeadm init初始化集群

在各节点开机启动kubelet服务:

systemctl enable kubelet.service

使用kubeadm config print init-defaults --component-configs KubeletConfiguration可以打印集群初始化默认的使用的配置:

apiVersion: kubeadm.k8s.io/v1beta3
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 1.2.3.4
  bindPort: 6443
nodeRegistration:
  criSocket: unix:///var/run/containerd/containerd.sock
  imagePullPolicy: IfNotPresent
  name: node
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta3
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns: {}
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
kubernetesVersion: 1.24.0
networking:
  dnsDomain: cluster.local
  serviceSubnet: 10.96.0.0/12
scheduler: {}
---
apiVersion: kubelet.config.k8s.io/v1beta1
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 0s
    enabled: true
  x509:
    clientCAFile: /etc/kubernetes/pki/ca.crt
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 0s
    cacheUnauthorizedTTL: 0s
cgroupDriver: systemd
clusterDNS:
- 10.96.0.10
clusterDomain: cluster.local
cpuManagerReconcilePeriod: 0s
evictionPressureTransitionPeriod: 0s
fileCheckFrequency: 0s
healthzBindAddress: 127.0.0.1
healthzPort: 10248
httpCheckFrequency: 0s
imageMinimumGCAge: 0s
kind: KubeletConfiguration
logging:
  flushFrequency: 0
  options:
    json:
      infoBufferSize: "0"
  verbosity: 0
memorySwap: {}
nodeStatusReportFrequency: 0s
nodeStatusUpdateFrequency: 0s
rotateCertificates: true
runtimeRequestTimeout: 0s
shutdownGracePeriod: 0s
shutdownGracePeriodCriticalPods: 0s
staticPodPath: /etc/kubernetes/manifests
streamingConnectionIdleTimeout: 0s
syncFrequency: 0s
volumeStatsAggPeriod: 0s

从默认的配置中可以看到,可以使用imageRepository定制在集群初始化时拉取k8s所需镜像的地址。基于默认配置定制出本次使用kubeadm初始化集群所需的配置文件kubeadm.yaml:

apiVersion: kubeadm.k8s.io/v1beta3
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 192.168.30.128
  bindPort: 6443
nodeRegistration:
  criSocket: unix:///run/containerd/containerd.sock
  taints:
  - effect: PreferNoSchedule
    key: node-role.kubernetes.io/master
---
apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
kubernetesVersion: v1.24.0
imageRepository: registry.aliyuncs.com/google_containers
networking:
  podSubnet: 10.244.0.0/16
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
cgroupDriver: systemd
failSwapOn: false
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs

这里定制了imageRepository为阿里云的registry,避免因gcr被墙,无法直接拉取镜像。criSocket设置了容器运行时为containerd。 同时设置kubelet的cgroupDriver为systemd,设置kube-proxy代理模式为ipvs。

在开始初始化集群之前可以使用kubeadm config images pull --config kubeadm.yaml预先在各个服务器节点上拉取所k8s需要的容器镜像。

kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.24.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.24.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.24.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.24.0
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.7
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.5.3-0
[config/images] Pulled registry.aliyuncs.com/google_containers/coredns:v1.8.6

接下来使用kubeadm初始化集群,选择node1作为Master Node,在node1上执行下面的命令:

kubeadm init --config kubeadm.yaml
W0807 15:37:06.325227  123939 common.go:84] your configuration file uses a deprecated API spec: "kubeadm.k8s.io/v1beta2". Please use 'kubeadm config migrate --old-config old.yaml --new-config new.yaml', which will write the new, similar spec using a newer API version.
[init] Using Kubernetes version: v1.24.0
[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 [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local vm-test-01] and IPs [10.96.0.1 192.168.30.128]
[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 [localhost vm-test-01] and IPs [192.168.30.128 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost vm-test-01] and IPs [192.168.30.128 127.0.0.1 ::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 6.002299 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config" 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 vm-test-01 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node vm-test-01 as control-plane by adding the taints [node-role.kubernetes.io/master:PreferNoSchedule]
[bootstrap-token] Using token: ss32ok.uk6b4xd8qsr8gb38
[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 192.168.30.128:6443 --token ss32ok.uk6b4xd8qsr8gb38 \
        --discovery-token-ca-cert-hash sha256:e02f1c9984af31c496b72e1816c90765fad47ca6e2a9e66633dc9443a1a44b64

上面记录了完成的初始化输出的内容,根据输出的内容基本上可以看出手动初始化安装一个Kubernetes集群所需要的关键步骤。 其中有以下关键内容:

  • [certs]生成相关的各种证书
  • [kubeconfig]生成相关的kubeconfig文件
  • [kubelet-start] 生成kubelet的配置文件"/var/lib/kubelet/config.yaml"
  • [control-plane]使用/etc/kubernetes/manifests目录中的yaml文件创建apiserver、controller-manager、scheduler的静态pod
  • [bootstraptoken]生成token记录下来,后边使用kubeadm join往集群中添加节点时会用到
  • 下面的命令是配置常规用户如何使用kubectl访问集群:
  • 最后给出了将节点加入集群的命令kubeadm join 192.168.30.128:6443 --token abcdef.0123456789abcdef --discovery-token-ca-cert-hash sha256:fd1155c303a58f52791f6cf7ac9653b023535de79ad3e2e0f49c63a82dcf93da
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

查看一下集群状态,确认个组件都处于healthy状态,结果出现了错误:

kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE                         ERROR
scheduler            Healthy   ok
etcd-0               Healthy   {"health":"true","reason":""}
controller-manager   Healthy   ok

2.3 安装包管理器helm 3

Helm是Kubernetes的包管理器,后续流程也将使用Helm安装Kubernetes的常用组件。 这里先在master节点node1上安装helm。

wget https://get.helm.sh/helm-v3.9.0-linux-amd64.tar.gz
tar -zxvf helm-v3.9.0-linux-amd64.tar.gz
mv linux-amd64/helm  /usr/local/bin/

执行helm list确认没有错误输出。

2.4 部署Pod Network组件Calico

选择calico作为k8s的Pod网络组件,下面使用helm在k8s集群中安装calico。

下载tigera-operator的helm chart:

wget https://github.com/projectcalico/calico/releases/download/v3.23.1/tigera-operator-v3.23.1.tgz

查看这个chart的中可定制的配置:

helm show values tigera-operator-v3.23.1.tgz

imagePullSecrets: {}

installation:
  enabled: true
  kubernetesProvider: ""

apiServer:
  enabled: true

certs:
  node:
    key:
    cert:
    commonName:
  typha:
    key:
    cert:
    commonName:
    caBundle:

resources: {}

# Configuration for the tigera operator
tigeraOperator:
  image: tigera/operator
  version: v1.27.1
  registry: quay.io
calicoctl:
  image: docker.io/calico/ctl
  tag: v3.23.1

定制的values.yaml如下:

# 可针对上面的配置进行定制,例如calico的镜像改成从私有库拉取。
# 这里只是个人本地环境测试k8s新版本,因此保留value.yaml为空即可

使用helm安装calico:

helm install calico tigera-operator-v3.23.1.tgz -n kube-system  --create-namespace -f values.yaml

等待并确认所有pod处于Running状态:

$kubectl get pod -n kube-system | grep tigera-operator
tigera-operator-5fb55776df-9gcc2     1/1     Running   0             6m20s

$kubectl get pods -n calico-system
NAME                                       READY   STATUS    RESTARTS   AGE
calico-kube-controllers-68884f975d-txcs4   1/1     Running   0          6m53s
calico-node-42f26                          1/1     Running   0          6m53s
calico-typha-6cbcbd5f7d-ksv8z              1/1     Running   0          6m53s

查看一下calico向k8s中添加的api资源:

kubectl api-resources | grep calico
bgpconfigurations                                                                 crd.projectcalico.org/v1               false        BGPConfigura             tion
bgppeers                                                                          crd.projectcalico.org/v1               false        BGPPeer
blockaffinities                                                                   crd.projectcalico.org/v1               false        BlockAffinit             y
caliconodestatuses                                                                crd.projectcalico.org/v1               false        CalicoNodeSt             atus
clusterinformations                                                               crd.projectcalico.org/v1               false        ClusterInfor             mation
felixconfigurations                                                               crd.projectcalico.org/v1               false        FelixConfigu             ration
globalnetworkpolicies                                                             crd.projectcalico.org/v1               false        GlobalNetwor             kPolicy
globalnetworksets                                                                 crd.projectcalico.org/v1               false        GlobalNetwor             kSet
hostendpoints                                                                     crd.projectcalico.org/v1               false        HostEndpoint
ipamblocks                                                                        crd.projectcalico.org/v1               false        IPAMBlock
ipamconfigs                                                                       crd.projectcalico.org/v1               false        IPAMConfig
ipamhandles                                                                       crd.projectcalico.org/v1               false        IPAMHandle
ippools                                                                           crd.projectcalico.org/v1               false        IPPool
ipreservations                                                                    crd.projectcalico.org/v1               false        IPReservatio             n
kubecontrollersconfigurations                                                     crd.projectcalico.org/v1               false        KubeControll             ersConfiguration
networkpolicies                                                                   crd.projectcalico.org/v1               true         NetworkPolic             y
networksets                                                                       crd.projectcalico.org/v1               true         NetworkSet
bgpconfigurations                 bgpconfig,bgpconfigs                            projectcalico.org/v3                   false        BGPConfigura             tion
bgppeers                                                                          projectcalico.org/v3                   false        BGPPeer
caliconodestatuses                caliconodestatus                                projectcalico.org/v3                   false        CalicoNodeSt             atus
clusterinformations               clusterinfo                                     projectcalico.org/v3                   false        ClusterInfor             mation
felixconfigurations               felixconfig,felixconfigs                        projectcalico.org/v3                   false        FelixConfigu             ration
globalnetworkpolicies             gnp,cgnp,calicoglobalnetworkpolicies            projectcalico.org/v3                   false        GlobalNetwor             kPolicy
globalnetworksets                                                                 projectcalico.org/v3                   false        GlobalNetwor             kSet
hostendpoints                     hep,heps                                        projectcalico.org/v3                   false        HostEndpoint
ippools                                                                           projectcalico.org/v3                   false        IPPool
ipreservations                                                                    projectcalico.org/v3                   false        IPReservatio             n
kubecontrollersconfigurations                                                     projectcalico.org/v3                   false        KubeControll             ersConfiguration
networkpolicies                   cnp,caliconetworkpolicy,caliconetworkpolicies   projectcalico.org/v3                   true         NetworkPolic             y
networksets                       netsets                                         projectcalico.org/v3                   true         NetworkSet
profiles                                                                          projectcalico.org/v3                   false        Profile

这些api资源是属于calico的,因此不建议使用kubectl来管理,推荐按照calicoctl来管理这些api资源。 将calicoctl安装为kubectl的插件:

cd /usr/local/bin
curl -o kubectl-calico -O -L  "https://github.com/projectcalico/calicoctl/releases/download/v3.21.5/calicoctl-linux-amd64" 
chmod +x kubectl-calico

验证插件正常工作:

kubectl calico -h

2.5 验证k8s DNS是否可用

kubectl run curl --image=radial/busyboxplus:curl -it
If you don't see a command prompt, try pressing enter.
[ root@curl:/ ]$

进入后执行nslookup kubernetes.default确认解析正常:

[ root@curl:/ ]$ nslookup kubernetes.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes.default
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local


2.6 向Kubernetes集群中添加Node节点

下面将node2, node3添加到Kubernetes集群中,分别在node2, node3上执行:

kubeadm join 192.168.30.128:6443 --token ss32ok.uk6b4xd8qsr8gb38 \
        --discovery-token-ca-cert-hash sha256:e02f1c9984af31c496b72e1816c90765fad47ca6e2a9e66633dc9443a1a44b64

若忘记这个join 命令,可以在主节点上执行命令:

kubeadm token create --print-join-command

node2和node3加入集群很是顺利,在master节点上执行命令查看集群中的节点:

NAME         STATUS   ROLES           AGE    VERSION
vm-test-01   Ready    control-plane   23h    v1.24.3
vm-test-02   Ready    <none>          6m4s   v1.24.3
vm-test-03   Ready    <none>          46s    v1.24.3

2.7 Kubernetes命令补全

安装bash-completion,执行如下命令:

$yum install bash-completion -y
$source <(kubectl completion bash)


3.Kubernetes常用组件部署

3.1 使用Helm部署ingress-nginx

为了便于将集群中的服务暴露到集群外部,需要使用Ingress。接下来使用Helm将ingress-nginx部署到Kubernetes上。 Nginx Ingress Controller被部署在Kubernetes的边缘节点上。

这里将node1(192.168.30.128)作为边缘节点,打上Label:

kubectl label node vm-test-01 node-role.kubernetes.io/edge=
node/vm-test-01 labeled

下载ingress-nginx的helm chart:

wget https://github.com/kubernetes/ingress-nginx/releases/download/helm-chart-4.1.2/ingress-nginx-4.1.2.tgz

查看ingress-nginx-4.1.2.tgz这个chart的可定制配置:

helm show values ingress-nginx-4.1.2.tgz

对values.yaml配置定制如下:

controller:
  ingressClassResource:
    name: nginx
    enabled: true
    default: true
    controllerValue: "k8s.io/ingress-nginx"
  admissionWebhooks:
    enabled: false
  replicaCount: 1
  image:
    # registry: k8s.gcr.io
    # image: ingress-nginx/controller
    # tag: "v1.1.0"
    registry: docker.io
    image: unreachableg/k8s.gcr.io_ingress-nginx_controller
    tag: "v1.2.0"
    digest: sha256:314435f9465a7b2973e3aa4f2edad7465cc7bcdc8304be5d146d70e4da136e51
  hostNetwork: true
  nodeSelector:
    node-role.kubernetes.io/edge: ''
  affinity:
    podAntiAffinity:
        requiredDuringSchedulingIgnoredDuringExecution:
        - labelSelector:
            matchExpressions:
            - key: app
              operator: In
              values:
              - nginx-ingress
            - key: component
              operator: In
              values:
              - controller
          topologyKey: kubernetes.io/hostname
  tolerations:
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: NoSchedule
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: PreferNoSchedule

nginx ingress controller的副本数replicaCount为1,将被调度到node1这个边缘节点上。这里并没有指定nginx ingress controller service的externalIPs,而是通过hostNetwork: true设置nginx ingress controller使用宿主机网络。 因为k8s.gcr.io被墙,这里替换成unreachableg/k8s.gcr.io_ingress-nginx_controller提前拉取一下镜像:

crictl pull unreachableg/k8s.gcr.io_ingress-nginx_controller:v1.2.0
helm install ingress-nginx ingress-nginx-4.1.2.tgz --create-namespace -n ingress-nginx -f values.yaml
 kubectl get pod -n ingress-nginx
NAME                                       READY   STATUS    RESTARTS   AGE
ingress-nginx-controller-9b7f9c4b5-7g8xs   1/1     Running   0          39s

测试访问http://192.168.30.128返回默认的nginx 404页,则部署完成。

3.2 使用Helm部署dashboard

先部署metrics-server:

wget https://github.com/kubernetes-sigs/metrics-server/releases/download/metrics-server-helm-chart-3.8.2/components.yaml

修改components.yaml中的image为docker.io/unreachableg/k8s.gcr.io_metrics-server_metrics-server:v0.6.1。 修改components.yaml中容器的启动参数,加入--kubelet-insecure-tls

kubectl apply -f components.yaml

metrics-server的pod正常启动后,等一段时间就可以使用kubectl top查看集群和pod的metrics信息:

kubectl top node
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
vm-test-01   222m         11%    2829Mi          74%
vm-test-02   59m          2%     964Mi           25%

kubectl top pod -n kube-system
NAME                                 CPU(cores)   MEMORY(bytes)
coredns-74586cf9b6-cbhfn             3m           22Mi
coredns-74586cf9b6-fxpl2             3m           12Mi
etcd-vm-test-01                      18m          50Mi
kube-apiserver-vm-test-01            57m          492Mi
kube-controller-manager-vm-test-01   16m          64Mi
kube-proxy-99jm8                     7m           13Mi
kube-proxy-wg84p                     9m           21Mi
kube-scheduler-vm-test-01            3m           24Mi
metrics-server-77cffb4988-kfm9g      3m           14Mi
tigera-operator-5fb55776df-8xznm     3m           45Mi

接下来使用helm部署k8s的dashboard,添加chart repo:

helm repo add kubernetes-dashboard https://kubernetes.github.io/dashboard/
helm repo update

查看chart的可定制配置:

helm show values kubernetes-dashboard/kubernetes-dashboard

对values.yaml定制配置如下:

image:
  repository: kubernetesui/dashboard
  tag: v2.5.1
ingress:
  enabled: true
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
  hosts:
  - k8s.example.com
  tls:
    - secretName: example-com-tls-secret
      hosts:
      - k8s.example.com
metricsScraper:
  enabled: true

先创建存放k8s.example.comssl证书的secret:

kubectl create secret tls example-com-tls-secret \
  --cert=cert.pem \
  --key=key.pem \
  -n kube-system

使用helm部署dashboard:

helm install kubernetes-dashboard kubernetes-dashboard/kubernetes-dashboard \
-n kube-system \
-f values.yaml

确认上面的命令部署成功。

创建管理员sa:

kubectl create serviceaccount kube-dashboard-admin-sa -n kube-system

kubectl create clusterrolebinding kube-dashboard-admin-sa \
--clusterrole=cluster-admin --serviceaccount=kube-system:kube-dashboard-admin-sa

创建集群管理员登录dashboard所需token:

kubectl create token kube-dashboard-admin-sa -n kube-system --duration=87600h

eyJhbGciOiJSUzI1NiIsImtpZCI6IlRJTkxRY3BKdUJsOE45NGtyVmplR0ROVDZjVC1oSUV1WU5XTHhlcVkwd00ifQ.eyJhdWQiOlsiaHR0cHM6Ly9rdWJlcm5ldGVzLmRlZmF1bHQuc3ZjLmNsdXN0ZXIubG9jYWwiXSwiZXhwIjoxOTc1NDYyNjUzLCJpYXQiOjE2NjAxMDI2NTMsImlzcyI6Imh0dHBzOi8va3ViZXJuZXRlcy5kZWZhdWx0LnN2Yy5jbHVzdGVyLmxvY2FsIiwia3ViZXJuZXRlcy5pbyI6eyJuYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsInNlcnZpY2VhY2NvdW50Ijp7Im5hbWUiOiJrdWJlLWRhc2hib2FyZC1hZG1pbi1zYSIsInVpZCI6IjdhNGY1MjYzLTAyYzMtNDM3Yy1iZTliLWQzMGQ2ZTJjM2JjMiJ9fSwibmJmIjoxNjYwMTAyNjUzLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06a3ViZS1kYXNoYm9hcmQtYWRtaW4tc2EifQ.rtNZ-sOYunJgFcDOzh-0piWLI35PWe7Hl_42VLKpgAG_tT2P20rswW4k2PXAKmjdmSGwIZjOmfHzywjfwi3sc41pju3LNSElxgwHAoZYEcoME_2TnrOvNYuDEgXHUhVVbA3wxuWecSG9_I7lgefBHW2On5Xc-4L41T1mueHIOIJwIodIMIU4BRinNSWL5JuMUtFsiK-WtJpudUiXcggNdX1eIA3tTfUSrWg7z1wq1py3sF6HAlxpMc-MSc1PltgbaaRjIOTDhi4I5-3YjeN0kOeTOdDveMZDx2msUvJPNzRA67b0mR9Pz1i4Dd_BDBzBypLzMnD2n-eYLHoIxX9kFA

使用上面的token登录k8s dashboard。

4. 问题

  • 添加k8s源后,执行apt-get udpdate 报错:GPG ERROR

解决:将pubkey加上

gpg --keyserver keyserver.ubuntu.com --recv-keys <pubkey>
gpg --export --armor <pubkey> | apt-key add -
  • incompatible CNI versions; config is \"1.0.0\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\"]"

解决: 下载最新的cni plugins内容

地址:https://github.com/containernetworking/plugins/releases/tag/v1.0.1

下载到服务器内后,备份并替换/opt/cni/bin/下内容 ,重启kubelet和containerd

5. 参考

  • https://blog.frognew.com/2022/05/kubeadm-install-kubernetes-1.24.html#32-%E4%BD%BF%E7%94%A8helm%E9%83%A8%E7%BD%B2dashboard
  • https://kubernetes.io/zh-cn/docs/tasks/administer-cluster/migrating-from-dockershim/troubleshooting-cni-plugin-related-errors/