使用kubeadm部署Kubernetes 1.24

使用kubeadm部署Kubernetes 1.24

2022-05-25
Kubernetes

kubeadm是Kubernetes官方提供的用于快速安部署Kubernetes集群的工具,伴随Kubernetes每个版本的发布都会同步更新,kubeadm会对集群配置方面的一些实践做调整,通过实验kubeadm可以学习到Kubernetes官方在集群配置上一些新的最佳实践。

1.准备 #

1.1 系统配置 #

在安装之前,需要先做好如下准备。3台CentOS 7.9主机如下:

1cat /etc/hosts
2192.168.96.151    node1
3192.168.96.152    node2
4192.168.96.153    node3

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。

禁用SELINUX:

1setenforce 0
1vi /etc/selinux/config
2SELINUX=disabled

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

1cat << EOF > /etc/modules-load.d/containerd.conf
2overlay
3br_netfilter
4EOF

执行以下命令使配置生效:

1modprobe overlay
2modprobe br_netfilter

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

1cat << EOF > /etc/sysctl.d/99-kubernetes-cri.conf
2net.bridge.bridge-nf-call-ip6tables = 1
3net.bridge.bridge-nf-call-iptables = 1
4net.ipv4.ip_forward = 1
5user.max_user_namespaces=28633
6EOF

执行以下命令使配置生效:

1sysctl -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:

1ip_vs
2ip_vs_rr
3ip_vs_wrr
4ip_vs_sh
5nf_conntrack_ipv4

在各个服务器节点上执行以下脚本:

1cat > /etc/sysconfig/modules/ipvs.modules <<EOF
2#!/bin/bash
3modprobe -- ip_vs
4modprobe -- ip_vs_rr
5modprobe -- ip_vs_wrr
6modprobe -- ip_vs_sh
7modprobe -- nf_conntrack_ipv4
8EOF
9chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

上面脚本创建了的/etc/sysconfig/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。

1yum install -y ipset ipvsadm

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:

1wget 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:

 1tar -zxvf cri-containerd-cni-1.6.4-linux-amd64.tar.gz -C /
 2
 3etc/
 4etc/systemd/
 5etc/systemd/system/
 6etc/systemd/system/containerd.service
 7etc/crictl.yaml
 8etc/cni/
 9etc/cni/net.d/
10etc/cni/net.d/10-containerd-net.conflist
11usr/
12usr/local/
13usr/local/sbin/
14usr/local/sbin/runc
15usr/local/bin/
16usr/local/bin/critest
17usr/local/bin/containerd-shim
18usr/local/bin/containerd-shim-runc-v1
19usr/local/bin/ctd-decoder
20usr/local/bin/containerd
21usr/local/bin/containerd-shim-runc-v2
22usr/local/bin/containerd-stress
23usr/local/bin/ctr
24usr/local/bin/crictl
25......
26opt/cni/
27opt/cni/bin/
28opt/cni/bin/bridge
29......

注意经测试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:

1wget https://github.com/opencontainers/runc/releases/download/v1.1.2/runc.amd64

接下来生成containerd的配置文件:

1mkdir -p /etc/containerd
2containerd 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

1[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
2  ...
3  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
4    SystemdCgroup = true

再修改/etc/containerd/config.toml中的

1[plugins."io.containerd.grpc.v1.cri"]
2  ...
3  # sandbox_image = "k8s.gcr.io/pause:3.6"
4  sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.7"

配置containerd开机启动,并启动containerd

1systemctl 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:

1crictl version
2Version:  0.1.0
3RuntimeName:  containerd
4RuntimeVersion:  v1.6.4
5RuntimeApiVersion:  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:

 1cat <<EOF > /etc/yum.repos.d/kubernetes.repo
 2[kubernetes]
 3name=Kubernetes
 4baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
 5enabled=1
 6gpgcheck=1
 7repo_gpgcheck=0
 8gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
 9        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
10EOF
1yum makecache fast
2yum install 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:

1swapoff -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:

1vm.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:

1systemctl 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:

 1apiVersion: kubeadm.k8s.io/v1beta3
 2bootstrapTokens:
 3- groups:
 4  - system:bootstrappers:kubeadm:default-node-token
 5  token: abcdef.0123456789abcdef
 6  ttl: 24h0m0s
 7  usages:
 8  - signing
 9  - authentication
10kind: InitConfiguration
11localAPIEndpoint:
12  advertiseAddress: 1.2.3.4
13  bindPort: 6443
14nodeRegistration:
15  criSocket: unix:///var/run/containerd/containerd.sock
16  imagePullPolicy: IfNotPresent
17  name: node
18  taints: null
19---
20apiServer:
21  timeoutForControlPlane: 4m0s
22apiVersion: kubeadm.k8s.io/v1beta3
23certificatesDir: /etc/kubernetes/pki
24clusterName: kubernetes
25controllerManager: {}
26dns: {}
27etcd:
28  local:
29    dataDir: /var/lib/etcd
30imageRepository: k8s.gcr.io
31kind: ClusterConfiguration
32kubernetesVersion: 1.24.0
33networking:
34  dnsDomain: cluster.local
35  serviceSubnet: 10.96.0.0/12
36scheduler: {}
37---
38apiVersion: kubelet.config.k8s.io/v1beta1
39authentication:
40  anonymous:
41    enabled: false
42  webhook:
43    cacheTTL: 0s
44    enabled: true
45  x509:
46    clientCAFile: /etc/kubernetes/pki/ca.crt
47authorization:
48  mode: Webhook
49  webhook:
50    cacheAuthorizedTTL: 0s
51    cacheUnauthorizedTTL: 0s
52cgroupDriver: systemd
53clusterDNS:
54- 10.96.0.10
55clusterDomain: cluster.local
56cpuManagerReconcilePeriod: 0s
57evictionPressureTransitionPeriod: 0s
58fileCheckFrequency: 0s
59healthzBindAddress: 127.0.0.1
60healthzPort: 10248
61httpCheckFrequency: 0s
62imageMinimumGCAge: 0s
63kind: KubeletConfiguration
64logging:
65  flushFrequency: 0
66  options:
67    json:
68      infoBufferSize: "0"
69  verbosity: 0
70memorySwap: {}
71nodeStatusReportFrequency: 0s
72nodeStatusUpdateFrequency: 0s
73rotateCertificates: true
74runtimeRequestTimeout: 0s
75shutdownGracePeriod: 0s
76shutdownGracePeriodCriticalPods: 0s
77staticPodPath: /etc/kubernetes/manifests
78streamingConnectionIdleTimeout: 0s
79syncFrequency: 0s
80volumeStatsAggPeriod: 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:

 1apiVersion: kubeadm.k8s.io/v1beta3
 2kind: InitConfiguration
 3localAPIEndpoint:
 4  advertiseAddress: 192.168.96.151
 5  bindPort: 6443
 6nodeRegistration:
 7  criSocket: unix:///run/containerd/containerd.sock
 8  taints:
 9  - effect: PreferNoSchedule
10    key: node-role.kubernetes.io/master
11---
12apiVersion: kubeadm.k8s.io/v1beta2
13kind: ClusterConfiguration
14kubernetesVersion: v1.24.0
15imageRepository: registry.aliyuncs.com/google_containers
16networking:
17  podSubnet: 10.244.0.0/16
18---
19apiVersion: kubelet.config.k8s.io/v1beta1
20kind: KubeletConfiguration
21cgroupDriver: systemd
22failSwapOn: false
23---
24apiVersion: kubeproxy.config.k8s.io/v1alpha1
25kind: KubeProxyConfiguration
26mode: 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。

1kubeadm config images pull --config kubeadm.yaml
2[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.24.0
3[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.24.0
4[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.24.0
5[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.24.0
6[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.7
7[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.5.3-0
8[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:

 1kubeadm init --config kubeadm.yaml
 2W0526 10:22:26.657615   24076 common.go:83] 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.
 3W0526 10:22:26.660300   24076 initconfiguration.go:120] Usage of CRI endpoints without URL scheme is deprecated and can cause kubelet errors in the future. Automatically prepending scheme "unix" to the "criSocket" with value "/run/containerd/containerd.sock". Please update your configuration!
 4[init] Using Kubernetes version: v1.24.0
 5[preflight] Running pre-flight checks
 6	[WARNING Swap]: swap is enabled; production deployments should disable swap unless testing the NodeSwap feature gate of the kubelet
 7[preflight] Pulling images required for setting up a Kubernetes cluster
 8[preflight] This might take a minute or two, depending on the speed of your internet connection
 9[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
10[certs] Using certificateDir folder "/etc/kubernetes/pki"
11[certs] Generating "ca" certificate and key
12[certs] Generating "apiserver" certificate and key
13[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local node1] and IPs [10.96.0.1 192.168.96.151]
14[certs] Generating "apiserver-kubelet-client" certificate and key
15[certs] Generating "front-proxy-ca" certificate and key
16[certs] Generating "front-proxy-client" certificate and key
17[certs] Generating "etcd/ca" certificate and key
18[certs] Generating "etcd/server" certificate and key
19[certs] etcd/server serving cert is signed for DNS names [localhost node1] and IPs [192.168.96.151 127.0.0.1 ::1]
20[certs] Generating "etcd/peer" certificate and key
21[certs] etcd/peer serving cert is signed for DNS names [localhost node1] and IPs [192.168.96.151 127.0.0.1 ::1]
22[certs] Generating "etcd/healthcheck-client" certificate and key
23[certs] Generating "apiserver-etcd-client" certificate and key
24[certs] Generating "sa" key and public key
25[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
26[kubeconfig] Writing "admin.conf" kubeconfig file
27[kubeconfig] Writing "kubelet.conf" kubeconfig file
28[kubeconfig] Writing "controller-manager.conf" kubeconfig file
29[kubeconfig] Writing "scheduler.conf" kubeconfig file
30[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
31[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
32[kubelet-start] Starting the kubelet
33[control-plane] Using manifest folder "/etc/kubernetes/manifests"
34[control-plane] Creating static Pod manifest for "kube-apiserver"
35[control-plane] Creating static Pod manifest for "kube-controller-manager"
36[control-plane] Creating static Pod manifest for "kube-scheduler"
37[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
38[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
39[apiclient] All control plane components are healthy after 17.506804 seconds
40[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
41[kubelet] Creating a ConfigMap "kubelet-config" in namespace kube-system with the configuration for the kubelets in the cluster
42[upload-certs] Skipping phase. Please see --upload-certs
43[mark-control-plane] Marking the node node1 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
44[mark-control-plane] Marking the node node1 as control-plane by adding the taints [node-role.kubernetes.io/master:PreferNoSchedule]
45[bootstrap-token] Using token: uufqmm.bvtfj4drwfvvbcev
46[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
47[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to get nodes
48[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
49[bootstrap-token] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
50[bootstrap-token] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
51[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
52[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
53[addons] Applied essential addon: CoreDNS
54[addons] Applied essential addon: kube-proxy
55
56Your Kubernetes control-plane has initialized successfully!
57
58To start using your cluster, you need to run the following as a regular user:
59
60  mkdir -p $HOME/.kube
61  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
62  sudo chown $(id -u):$(id -g) $HOME/.kube/config
63
64Alternatively, if you are the root user, you can run:
65
66  export KUBECONFIG=/etc/kubernetes/admin.conf
67
68You should now deploy a pod network to the cluster.
69Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
70  https://kubernetes.io/docs/concepts/cluster-administration/addons/
71
72Then you can join any number of worker nodes by running the following on each as root:
73
74kubeadm join 192.168.96.151:6443 --token uufqmm.bvtfj4drwfvvbcev \
75	--discovery-token-ca-cert-hash sha256:5814415567d93f6d2d41fe4719be8221f45c29c482b5059aec2e27a832ac36e6

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:
    1mkdir -p $HOME/.kube
    2sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
    3sudo chown $(id -u):$(id -g) $HOME/.kube/config
    
  • 最后给出了将节点加入集群的命令kubeadm join 192.168.96.151:6443 --token uufqmm.bvtfj4drwfvvbcev \ --discovery-token-ca-cert-hash sha256:5814415567d93f6d2d41fe4719be8221f45c29c482b5059aec2e27a832ac36e6

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:

1kubectl get cs
2Warning: v1 ComponentStatus is deprecated in v1.19+
3NAME                 STATUS    MESSAGE                         ERROR
4scheduler            Healthy   ok
5controller-manager   Healthy   ok
6etcd-0               Healthy   {"health":"true","reason":""}

集群初始化如果遇到问题,可以使用kubeadm reset命令进行清理。

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。

1wget https://get.helm.sh/helm-v3.9.0-linux-amd64.tar.gz
2tar -zxvf helm-v3.9.0-linux-amd64.tar.gz
3mv 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:

1wget 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:

 1helm show values tigera-operator-v3.23.1.tgz
 2
 3imagePullSecrets: {}
 4
 5installation:
 6  enabled: true
 7  kubernetesProvider: ""
 8
 9apiServer:
10  enabled: true
11
12certs:
13  node:
14    key:
15    cert:
16    commonName:
17  typha:
18    key:
19    cert:
20    commonName:
21    caBundle:
22
23resources: {}
24
25# Configuration for the tigera operator
26tigeraOperator:
27  image: tigera/operator
28  version: v1.27.1
29  registry: quay.io
30calicoctl:
31  image: docker.io/calico/ctl
32  tag: v3.23.1

定制的values.yaml如下:

1# 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。
2# 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:

1helm 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:

1kubectl get pod -n kube-system | grep tigera-operator
2tigera-operator-5fb55776df-wxbph   1/1     Running   0             5m10s
3
4kubectl get pods -n calico-system
5NAME                                       READY   STATUS    RESTARTS   AGE
6calico-kube-controllers-68884f975d-5d7p9   1/1     Running   0          5m24s
7calico-node-twbdh                          1/1     Running   0          5m24s
8calico-typha-7b4bdd99c5-ssdn2              1/1     Running   0          5m24s

查看一下calico向k8s中添加的api资源:

 1kubectl api-resources | grep calico
 2bgpconfigurations                                                                 crd.projectcalico.org/v1               false        BGPConfiguration
 3bgppeers                                                                          crd.projectcalico.org/v1               false        BGPPeer
 4blockaffinities                                                                   crd.projectcalico.org/v1               false        BlockAffinity
 5caliconodestatuses                                                                crd.projectcalico.org/v1               false        CalicoNodeStatus
 6clusterinformations                                                               crd.projectcalico.org/v1               false        ClusterInformation
 7felixconfigurations                                                               crd.projectcalico.org/v1               false        FelixConfiguration
 8globalnetworkpolicies                                                             crd.projectcalico.org/v1               false        GlobalNetworkPolicy
 9globalnetworksets                                                                 crd.projectcalico.org/v1               false        GlobalNetworkSet
10hostendpoints                                                                     crd.projectcalico.org/v1               false        HostEndpoint
11ipamblocks                                                                        crd.projectcalico.org/v1               false        IPAMBlock
12ipamconfigs                                                                       crd.projectcalico.org/v1               false        IPAMConfig
13ipamhandles                                                                       crd.projectcalico.org/v1               false        IPAMHandle
14ippools                                                                           crd.projectcalico.org/v1               false        IPPool
15ipreservations                                                                    crd.projectcalico.org/v1               false        IPReservation
16kubecontrollersconfigurations                                                     crd.projectcalico.org/v1               false        KubeControllersConfiguration
17networkpolicies                                                                   crd.projectcalico.org/v1               true         NetworkPolicy
18networksets                                                                       crd.projectcalico.org/v1               true         NetworkSet
19bgpconfigurations                 bgpconfig,bgpconfigs                            projectcalico.org/v3                   false        BGPConfiguration
20bgppeers                                                                          projectcalico.org/v3                   false        BGPPeer
21caliconodestatuses                caliconodestatus                                projectcalico.org/v3                   false        CalicoNodeStatus
22clusterinformations               clusterinfo                                     projectcalico.org/v3                   false        ClusterInformation
23felixconfigurations               felixconfig,felixconfigs                        projectcalico.org/v3                   false        FelixConfiguration
24globalnetworkpolicies             gnp,cgnp,calicoglobalnetworkpolicies            projectcalico.org/v3                   false        GlobalNetworkPolicy
25globalnetworksets                                                                 projectcalico.org/v3                   false        GlobalNetworkSet
26hostendpoints                     hep,heps                                        projectcalico.org/v3                   false        HostEndpoint
27ippools                                                                           projectcalico.org/v3                   false        IPPool
28ipreservations                                                                    projectcalico.org/v3                   false        IPReservation
29kubecontrollersconfigurations                                                     projectcalico.org/v3                   false        KubeControllersConfiguration
30networkpolicies                   cnp,caliconetworkpolicy,caliconetworkpolicies   projectcalico.org/v3                   true         NetworkPolicy
31networksets                       netsets                                         projectcalico.org/v3                   true         NetworkSet
32profiles                                                                          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:

1cd /usr/local/bin
2curl -o kubectl-calico -O -L  "https://github.com/projectcalico/calicoctl/releases/download/v3.21.5/calicoctl-linux-amd64" 
3chmod +x kubectl-calico

验证插件正常工作:

1kubectl calico -h

2.5 验证k8s DNS是否可用 #

1kubectl run curl --image=radial/busyboxplus:curl -it
2If you don't see a command prompt, try pressing enter.
3[ root@curl:/ ]$

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

1nslookup kubernetes.default
2Server:    10.96.0.10
3Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
4
5Name:      kubernetes.default
6Address 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:

1kubeadm join 192.168.96.151:6443 --token uufqmm.bvtfj4drwfvvbcev \
2	--discovery-token-ca-cert-hash sha256:5814415567d93f6d2d41fe4719be8221f45c29c482b5059aec2e27a832ac36e6

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:

1kubectl get node
2NAME    STATUS   ROLES                  AGE     VERSION
3node1   Ready    control-plane,master   29m     v1.24.0
4node2   Ready    <none>                 70s     v1.24.0
5node3   Ready    <none>                 58s     v1.24.0

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(192.168.96.151)作为边缘节点,打上Label:

1kubectl label node node1 node-role.kubernetes.io/edge=

下载ingress-nginx的helm chart:

1wget 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:

1helm show values ingress-nginx-4.1.2.tgz

对values.yaml配置定制如下:

 1controller:
 2  ingressClassResource:
 3    name: nginx
 4    enabled: true
 5    default: true
 6    controllerValue: "k8s.io/ingress-nginx"
 7  admissionWebhooks:
 8    enabled: false
 9  replicaCount: 1
10  image:
11    # registry: k8s.gcr.io
12    # image: ingress-nginx/controller
13    # tag: "v1.1.0"
14    registry: docker.io
15    image: unreachableg/k8s.gcr.io_ingress-nginx_controller
16    tag: "v1.2.0"
17    digest: sha256:314435f9465a7b2973e3aa4f2edad7465cc7bcdc8304be5d146d70e4da136e51
18  hostNetwork: true
19  nodeSelector:
20    node-role.kubernetes.io/edge: ''
21  affinity:
22    podAntiAffinity:
23        requiredDuringSchedulingIgnoredDuringExecution:
24        - labelSelector:
25            matchExpressions:
26            - key: app
27              operator: In
28              values:
29              - nginx-ingress
30            - key: component
31              operator: In
32              values:
33              - controller
34          topologyKey: kubernetes.io/hostname
35  tolerations:
36      - key: node-role.kubernetes.io/master
37        operator: Exists
38        effect: NoSchedule
39      - key: node-role.kubernetes.io/master
40        operator: Exists
41        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:

1crictl pull unreachableg/k8s.gcr.io_ingress-nginx_controller:v1.2.0
1helm install ingress-nginx ingress-nginx-4.1.2.tgz --create-namespace -n ingress-nginx -f values.yaml
1kubectl get pod -n ingress-nginx
2NAME                                        READY   STATUS    RESTARTS   AGE
3ingress-nginx-controller-7f574989bc-xwbf4   1/1     Running   0          117s

测试访问http://192.168.96.151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:

1wget 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:v0.5.2。 修改components.yaml中容器的启动参数,加入--kubelet-insecure-tls

1kubectl 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:

 1kubectl top node
 2NAME    CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
 3node1   509m         12%    3654Mi          47%
 4node2   133m         3%     1786Mi          23%
 5node3   117m         2%     1810Mi          23%
 6
 7kubectl top pod -n kube-system
 8NAME                               CPU(cores)   MEMORY(bytes)
 9coredns-74586cf9b6-575nl           6m           16Mi
10coredns-74586cf9b6-mbn8s           5m           17Mi
11etcd-node1                         49m          91Mi
12kube-apiserver-node1               142m         490Mi
13kube-controller-manager-node1      38m          54Mi
14kube-proxy-k5lzs                   26m          19Mi
15kube-proxy-rb5pf                   9m           15Mi
16kube-proxy-w5zpk                   27m          16Mi
17kube-scheduler-node1               7m           18Mi
18metrics-server-8dfd488f5-r8pbh     8m           21Mi
19tigera-operator-5fb55776df-wxbph   10m          38Mi

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

1helm repo add kubernetes-dashboard https://kubernetes.github.io/dashboard/
2helm repo update

查看chart的可定制配置:

1helm show values kubernetes-dashboard/kubernetes-dashboard

对values.yaml定制配置如下:

 1image:
 2  repository: kubernetesui/dashboard
 3  tag: v2.5.1
 4ingress:
 5  enabled: true
 6  annotations:
 7    nginx.ingress.kubernetes.io/ssl-redirect: "true"
 8    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
 9  hosts:
10  - k8s.example.com
11  tls:
12    - secretName: example-com-tls-secret
13      hosts:
14      - k8s.example.com
15metricsScraper:
16  enabled: true

先创建存放k8s.example.comssl证书的secret:

1kubectl create secret tls example-com-tls-secret \
2  --cert=cert.pem \
3  --key=key.pem \
4  -n kube-system

使用helm部署dashboard:

1helm install kubernetes-dashboard kubernetes-dashboard/kubernetes-dashboard \
2-n kube-system \
3-f values.yaml

确认上面的命令部署成功。

创建管理员sa:

1kubectl create serviceaccount kube-dashboard-admin-sa -n kube-system
2
3kubectl create clusterrolebinding kube-dashboard-admin-sa \
4--clusterrole=cluster-admin --serviceaccount=kube-system:kube-dashboard-admin-sa

创建集群管理员登录dashboard所需token:

1kubectl create token kube-dashboard-admin-sa -n kube-system --duration=87600h
2
3eyJhbGciOiJSUzI1NiIsImtpZCI6IlU1SlpSTS1YekNuVzE0T1k5TUdTOFFqN25URWxKckt6OUJBT0xzblBsTncifQ.eyJhdWQiOlsiaHR0cHM6Ly9rdWJlcm5ldGVzLmRlZmF1bHQuc3ZjLmNsdXN0ZXIubG9jYWwiXSwiZXhwIjoxOTY4OTA4MjgyLCJpYXQiOjE2NTM1NDgyODIsImlzcyI6Imh0dHBzOi8va3ViZXJuZXRlcy5kZWZhdWx0LnN2Yy5jbHVzdGVyLmxvY2FsIiwia3ViZXJuZXRlcy5pbyI6eyJuYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsInNlcnZpY2VhY2NvdW50Ijp7Im5hbWUiOiJrdWJlLWRhc2hib2FyZC1hZG1pbi1zYSIsInVpZCI6IjY0MmMwMmExLWY1YzktNDFjNy04Mjc5LWQ1ZmI3MGRjYTQ3ZSJ9fSwibmJmIjoxNjUzNTQ4MjgyLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06a3ViZS1kYXNoYm9hcmQtYWRtaW4tc2EifQ.Xqxlo2vJ9Hb6UUVIqwvc8I5bahdxKzSRSaQI_67Yt7_YEHmkkHApxUGlwJYTKF9ufww3btlCmM8PtRn5_Q1yv-HAFyTOYKo8WHZ9UCm1bT3X8V8g4GQwZIl2dwmlUmKb1unBz2-em2uThQ015bMPDE8a42DV_bOwWjljVXat0nwV14nGorC8vKLjXbohrIJ3G1pgCJvlBn99F1RelmSUSQLlolUFoxpN6MamYTElwR6FfD-AGmFXvZSbcFaqVW0oxJHV70Gjs2igOtpqHFxxPlHT8aQzlRiybPtFyBf9Ll87TmVJimT89z8wv2si2Nee8bB2jhsApLn8TJyUSlbTXA

使用上面的token登录k8s dashboard。

dashboard

参考 #

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