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使用kubeadm部署Kubernetes 1.28

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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,kubeadm可能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Linux主机如下:

  • node4 – Ubuntu 22.04
  • node5 – openEuler release 22.03 (LTS-SP2)
  • node6 – Rocky Linux release 8.8 (Green Obsidian)
1cat /etc/hosts
2192.168.96.154    node4
3192.168.96.155    node5
4192.168.96.156    node6

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。

创建/etc/modules-load.d/containerd.conf配置文件,确保在系统启动时自动加载所需的内核模块,以满足容器运行时的要求:

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

在文件名/etc/sysctl.d/99-kubernetes-cri.conf中,“99” 代表文件的优先级或顺序。sysctl是Linux内核参数的配置工具,它可以通过修改/proc/sys/目录下的文件来设置内核参数。在/etc/sysctl.d/目录中,可以放置一系列的配置文件,以便在系统启动时自动加载这些参数。这些配置文件按照文件名的字母顺序逐个加载。数字前缀用于指定加载的顺序,较小的数字表示较高的优先级。

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

创建/etc/modules-load.d/ipvs.conf文件,保证在节点重启后能自动加载所需模块:

1cat > /etc/modules-load.d/ipvs.conf <<EOF
2ip_vs
3ip_vs_rr
4ip_vs_wrr
5ip_vs_sh
6EOF

执行以下命令使配置立即生效:

1modprobe ip_vs
2modprobe ip_vs_rr
3modprobe ip_vs_wrr
4modprobe ip_vs_sh

使用lsmod | grep -e ip_vs -e nf_conntrack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。

在Ubuntu系统上执行:

1apt install -y ipset ipvsadm

在openEuler或Rocky Linux系统上执行:

1yum install -y ipset ipvsadm

如果不满足以上前提条件,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, 需要注意cri-containerd-(cni-)-VERSION-OS-ARCH.tar.gz发行包自containerd 1.6版本起已经被弃用,在某些 Linux 发行版上无法正常工作,并将在containerd 2.0版本中移除,这里下载containerd-<VERSION>-<OS>-<ARCH>.tar.gz的发行包,后边在单独下载安装runc和CNI plugins:

1wget https://github.com/containerd/containerd/releases/download/v1.7.3/containerd-1.7.3-linux-amd64.tar.gz

将其解压缩到/usr/local下:

1tar Cxzvf /usr/local containerd-1.7.3-linux-amd64.tar.gz
2
3bin/
4bin/containerd-shim-runc-v1
5bin/containerd-shim-runc-v2
6bin/containerd-stress
7bin/containerd
8bin/containerd-shim
9bin/ctr

接下来从runc的github上单独下载安装runc,该二进制文件是静态构建的,并且应该适用于任何Linux发行版。

1wget https://github.com/opencontainers/runc/releases/download/v1.1.9/runc.amd64
2install -m 755 runc.amd64 /usr/local/sbin/runc

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 = "registry.k8s.io/pause:3.8"
4  sandbox_image = "registry.aliyuncs.com/google_containers/pause:3.9"

为了通过systemd启动containerd,请还需要从https://raw.githubusercontent.com/containerd/containerd/main/containerd.service下载containerd.service单元文件,并将其放置在 /etc/systemd/system/containerd.service中。

 1cat << EOF > /etc/systemd/system/containerd.service
 2[Unit]
 3Description=containerd container runtime
 4Documentation=https://containerd.io
 5After=network.target local-fs.target
 6
 7[Service]
 8#uncomment to enable the experimental sbservice (sandboxed) version of containerd/cri integration
 9#Environment="ENABLE_CRI_SANDBOXES=sandboxed"
10ExecStartPre=-/sbin/modprobe overlay
11ExecStart=/usr/local/bin/containerd
12
13Type=notify
14Delegate=yes
15KillMode=process
16Restart=always
17RestartSec=5
18# Having non-zero Limit*s causes performance problems due to accounting overhead
19# in the kernel. We recommend using cgroups to do container-local accounting.
20LimitNPROC=infinity
21LimitCORE=infinity
22LimitNOFILE=infinity
23# Comment TasksMax if your systemd version does not supports it.
24# Only systemd 226 and above support this version.
25TasksMax=infinity
26OOMScoreAdjust=-999
27
28[Install]
29WantedBy=multi-user.target
30EOF

配置containerd开机启动,并启动containerd,执行以下命令:

1systemctl daemon-reload
2systemctl enable containerd --now 
3systemctl status containerd

下载安装crictl工具:

1wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.28.0/crictl-v1.28.0-linux-amd64.tar.gz
2tar -zxvf crictl-v1.28.0-linux-amd64.tar.gz
3install -m 755 crictl /usr/local/bin/crictl

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 --runtime-endpoint=unix:///run/containerd/containerd.sock  version
2
3Version:  0.1.0
4RuntimeName:  containerd
5RuntimeVersion:  v1.7.3
6RuntimeApiVersion:  v1

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:

在Ubuntu系统上执行下面的命令:

 1apt-get update
 2apt-get install -y apt-transport-https ca-certificates curl
 3
 4curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -
 5
 6
 7tee /etc/apt/sources.list.d/kubernetes.list <<-'EOF'
 8deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
 9EOF
10
11apt-get update
12
13apt install kubelet kubeadm kubectl
14
15apt-mark hold kubelet kubeadm kubectl

在openEuler和Rocky Linux系统中执行下面的命令:

 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
11
12
13yum makecache
14yum install kubelet kubeadm kubectl

上面的命令在安装kubeadm, kubectl, kubelet 时,会自动安装依赖项conntrack, cri-tools, ebtables, kubernetes-cni, soca

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: registry.k8s.io
31kind: ClusterConfiguration
32kubernetesVersion: 1.28.0
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
56containerRuntimeEndpoint: ""
57cpuManagerReconcilePeriod: 0s
58evictionPressureTransitionPeriod: 0s
59fileCheckFrequency: 0s
60healthzBindAddress: 127.0.0.1
61healthzPort: 10248
62httpCheckFrequency: 0s
63imageMinimumGCAge: 0s
64kind: KubeletConfiguration
65logging:
66  flushFrequency: 0
67  options:
68    json:
69      infoBufferSize: "0"
70  verbosity: 0
71memorySwap: {}
72nodeStatusReportFrequency: 0s
73nodeStatusUpdateFrequency: 0s
74resolvConf: /run/systemd/resolve/resolv.conf
75rotateCertificates: true
76runtimeRequestTimeout: 0s
77shutdownGracePeriod: 0s
78shutdownGracePeriodCriticalPods: 0s
79staticPodPath: /etc/kubernetes/manifests
80streamingConnectionIdleTimeout: 0s
81syncFrequency: 0s
82volumeStatsAggPeriod: 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: 192.168.96.154
 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/v1beta3
13kind: ClusterConfiguration
14kubernetesVersion: 1.28.0
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cgroupDriversystemd,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
3[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.28.0
4[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.28.0
5[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.28.0
6[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.28.0
7[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.9
8[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.5.9-0
9[config/images] Pulled registry.aliyuncs.com/google_containers/coredns:v1.10.1

接下来使用kubeadm初始化集群,选择node4作为Master Node,在node4上执行下面的命令:

 1kubeadm init --config kubeadm.yaml
 2
 3[init] Using Kubernetes version: v1.28.0
 4[preflight] Running pre-flight checks
 5        [WARNING Swap]: swap is enabled; production deployments should disable swap unless testing the NodeSwap feature gate of the kubelet
 6[preflight] Pulling images required for setting up a Kubernetes cluster
 7[preflight] This might take a minute or two, depending on the speed of your internet connection
 8[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
 9[certs] Using certificateDir folder "/etc/kubernetes/pki"
10[certs] Generating "ca" certificate and key
11[certs] Generating "apiserver" certificate and key
12[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local node4] and IPs [10.96.0.1 192.168.96.154]
13[certs] Generating "apiserver-kubelet-client" certificate and key
14[certs] Generating "front-proxy-ca" certificate and key
15[certs] Generating "front-proxy-client" certificate and key
16[certs] Generating "etcd/ca" certificate and key
17[certs] Generating "etcd/server" certificate and key
18[certs] etcd/server serving cert is signed for DNS names [localhost node4] and IPs [192.168.96.154 127.0.0.1 ::1]
19[certs] Generating "etcd/peer" certificate and key
20[certs] etcd/peer serving cert is signed for DNS names [localhost node4] and IPs [192.168.96.154 127.0.0.1 ::1]
21[certs] Generating "etcd/healthcheck-client" certificate and key
22[certs] Generating "apiserver-etcd-client" certificate and key
23[certs] Generating "sa" key and public key
24[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
25[kubeconfig] Writing "admin.conf" kubeconfig file
26[kubeconfig] Writing "kubelet.conf" kubeconfig file
27[kubeconfig] Writing "controller-manager.conf" kubeconfig file
28[kubeconfig] Writing "scheduler.conf" kubeconfig file
29[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
30[control-plane] Using manifest folder "/etc/kubernetes/manifests"
31[control-plane] Creating static Pod manifest for "kube-apiserver"
32[control-plane] Creating static Pod manifest for "kube-controller-manager"
33[control-plane] Creating static Pod manifest for "kube-scheduler"
34[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
35[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
36[kubelet-start] Starting the kubelet
37[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
38[apiclient] All control plane components are healthy after 17.507599 seconds
39[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
40[kubelet] Creating a ConfigMap "kubelet-config" in namespace kube-system with the configuration for the kubelets in the cluster
41[upload-certs] Skipping phase. Please see --upload-certs
42[mark-control-plane] Marking the node node4 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
43[mark-control-plane] Marking the node node4 as control-plane by adding the taints [node-role.kubernetes.io/master:PreferNoSchedule]
44[bootstrap-token] Using token: ag6egz.xjq1zz01meq8iboq
45[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
46[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to get nodes
47[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
48[bootstrap-token] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
49[bootstrap-token] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
50[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
51[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
52[addons] Applied essential addon: CoreDNS
53[addons] Applied essential addon: kube-proxy
54
55Your Kubernetes control-plane has initialized successfully!
56
57To start using your cluster, you need to run the following as a regular user:
58
59  mkdir -p $HOME/.kube
60  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
61  sudo chown $(id -u):$(id -g) $HOME/.kube/config
62
63Alternatively, if you are the root user, you can run:
64
65  export KUBECONFIG=/etc/kubernetes/admin.conf
66
67You should now deploy a pod network to the cluster.
68Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
69  https://kubernetes.io/docs/concepts/cluster-administration/addons/
70
71Then you can join any number of worker nodes by running the following on each as root:
72
73kubeadm join 192.168.96.154:6443 --token ag6egz.xjq1zz01meq8iboq \
74        --discovery-token-ca-cert-hash sha256:3a13ba07a146b904a10fe2e3f0ea0056890f522c327eed073f8952a5b182883a

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
  • [addons]安装基本插件:CoreDNSkube-proxy
  • 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
  • 最后给出了将另外2个节点加入集群的命令:
1kubeadm join 192.168.96.154:6443 --token ag6egz.xjq1zz01meq8iboq \
2        --discovery-token-ca-cert-hash sha256:3a13ba07a146b904a10fe2e3f0ea0056890f522c327eed073f8952a5b182883a

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
2
3Warning: v1 ComponentStatus is deprecated in v1.19+
4NAME                 STATUS    MESSAGE   ERROR
5controller-manager   Healthy   ok
6scheduler            Healthy   ok
7etcd-0               Healthy   ok

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node4上安装helm。

1wget https://get.helm.sh/helm-v3.12.3-linux-amd64.tar.gz
2tar -zxvf helm-v3.12.3-linux-amd64.tar.gz
3install -m 755 linux-amd64/helm  /usr/local/bin/helm

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/v3.26.1/tigera-operator-v3.26.1.tgz

查看这个chart的中可定制的配置:

 1helm show values tigera-operator-v3.26.1.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
23# Resource requests and limits for the tigera/operator pod.
24resources: {}
25
26# Tolerations for the tigera/operator pod.
27tolerations:
28- effect: NoExecute
29  operator: Exists
30- effect: NoSchedule
31  operator: Exists
32
33# NodeSelector for the tigera/operator pod.
34nodeSelector:
35  kubernetes.io/os: linux
36
37# Custom annotations for the tigera/operator pod.
38podAnnotations: {}
39
40# Custom labels for the tigera/operator pod.
41podLabels: {}
42
43# Image and registry configuration for the tigera/operator pod.
44tigeraOperator:
45  image: tigera/operator
46  version: v1.30.4
47  registry: quay.io
48calicoctl:
49  image: docker.io/calico/ctl
50  tag: v3.26.1

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,因此只有下面几行配置
3apiServer:
4  enabled: false
5installation:
6  kubeletVolumePluginPath: None

使用helm安装calico:

1helm install calico tigera-operator-v3.26.1.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
 3bgpfilters                                     crd.projectcalico.org/v1               false        BGPFilter
 4bgppeers                                       crd.projectcalico.org/v1               false        BGPPeer
 5blockaffinities                                crd.projectcalico.org/v1               false        BlockAffinity
 6caliconodestatuses                             crd.projectcalico.org/v1               false        CalicoNodeStatus
 7clusterinformations                            crd.projectcalico.org/v1               false        ClusterInformation
 8felixconfigurations                            crd.projectcalico.org/v1               false        FelixConfiguration
 9globalnetworkpolicies                          crd.projectcalico.org/v1               false        GlobalNetworkPolicy
10globalnetworksets                              crd.projectcalico.org/v1               false        GlobalNetworkSet
11hostendpoints                                  crd.projectcalico.org/v1               false        HostEndpoint
12ipamblocks                                     crd.projectcalico.org/v1               false        IPAMBlock
13ipamconfigs                                    crd.projectcalico.org/v1               false        IPAMConfig
14ipamhandles                                    crd.projectcalico.org/v1               false        IPAMHandle
15ippools                                        crd.projectcalico.org/v1               false        IPPool
16ipreservations                                 crd.projectcalico.org/v1               false        IPReservation
17kubecontrollersconfigurations                  crd.projectcalico.org/v1               false        KubeControllersConfiguration
18networkpolicies                                crd.projectcalico.org/v1               true         NetworkPolicy
19networksets                                    crd.projectcalico.org/v1               true         NetworkSet

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node5, node6添加到Kubernetes集群中,分别在node5, node6上执行:

1kubeadm join 192.168.96.154:6443 --token ag6egz.xjq1zz01meq8iboq \
2        --discovery-token-ca-cert-hash sha256:3a13ba07a146b904a10fe2e3f0ea0056890f522c327eed073f8952a5b182883a

node5和node6加入集群时遇到了如下问题,调度到node5(openEuler 22.03系统)或node6(Rock Linux 8.8)的calico-typha Pod无法启动,并报下面的错误:

1kubectl describe po calico-typha-7bb687bdb4-zptbt -n calico-system
2...
3kubelet   Failed to create pod sandbox: open /run/systemd/resolve/resolv.conf: no such file or directory

/run/systemd/resolve/resolv.conf 文件是由systemd-resolved服务管理的。Ubuntu 22.04上默认安装并启动了这个服务。openEuler 22.03上没有安装这个服务。Rocky Linux 8.8上默认安装但没有启动这个服务。

下面node5上安装并启动systemd-resolved:

1yum install -y systemd-resolved
2systemctl enable systemd-resolved --now
3systemctl status systemd-resolved

在node6上启动systemd-resolved:

1systemctl enable systemd-resolved --now
2systemctl status systemd-resolved

之后3个节点上的calico相关pod全部启动正常:

1kubectl get po -n calico-system -o wide
2NAME                                       READY   STATUS    RESTARTS   AGE   IP               NODE    NOMINATED NODE   READINESS GATES
3calico-kube-controllers-58b9468dd6-g26fb   1/1     Running   0          48m   10.244.3.66      node4   <none>           <none>
4calico-node-h9m7k                          1/1     Running   0          37m   192.168.96.156   node6   <none>           <none>
5calico-node-rdv64                          1/1     Running   0          48m   192.168.96.154   node4   <none>           <none>
6calico-node-z5c4q                          1/1     Running   0          37m   192.168.96.155   node5   <none>           <none>
7calico-typha-7bb687bdb4-52kcv              1/1     Running   0          48m   192.168.96.154   node4   <none>           <none>
8calico-typha-7bb687bdb4-zptbt              1/1     Running   0          23m   192.168.96.156   node6   <none>           <none>

在master节点上执行命令查看集群中的节点(需要等待新加入节点上的calico-node pod启动正常):

1kubectl get node
2NAME    STATUS   ROLES           AGE   VERSION
3node4   Ready    control-plane   62m   v1.28.0
4node5   Ready    <none>          39m   v1.28.0
5node6   Ready    <none>          39m   v1.28.0

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node4(192.168.96.154)作为边缘节点,打上Label:

1kubectl label node node4 node-role.kubernetes.io/edge=

下载ingress-nginx的helm chart:

1wget https://github.com/kubernetes/ingress-nginx/releases/download/helm-chart-4.7.0/ingress-nginx-4.7.0.tgz

查看ingress-nginx-4.7.0.tgz这个chart的可定制配置:

1helm show values ingress-nginx-4.7.0.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: registry.k8s.io
12    # image: ingress-nginx/controller
13    # tag: "v1.8.0"
14    registry: docker.io
15    image: unreachableg/registry.k8s.io_ingress-nginx_controller
16    tag: "v1.8.0"
17    digest: sha256:626fc8847e967dc06049c0eda9e093d77a08feff80179ae97538ba8b118570f3
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node4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registry.k8s.io被墙,这里替换成unreachableg/registry.k8s.io_ingress-nginx_controller提前拉取一下镜像:

1crictl --runtime-endpoint=unix:///run/containerd/containerd.sock pull unreachableg/registry.k8s.io_ingress-nginx_controller:v1.8.0
1helm install ingress-nginx ingress-nginx-4.7.0.tgz --create-namespace -n ingress-nginx -f values.yaml
1kubectl get po -n ingress-nginx
2NAME                                        READY   STATUS    RESTARTS   AGE
3ingress-nginx-controller-86878885cd-m9xc4   1/1     Running   0          45s

测试访问http://192.168.96.154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/v0.6.4/components.yaml

修改components.yaml中的image为docker.io/unreachableg/k8s.gcr.io_metrics-server_metrics-server:v0.6.4。 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%
 3node4   246m         6%     2296Mi          29%
 4node5   145m         3%     810Mi           10%
 5node6   97m          2%     933Mi           12%
 6
 7kubectl top pod -n kube-system
 8NAME                              CPU(cores)   MEMORY(bytes)
 9coredns-66f779496c-7mlsm          3m           12Mi
10coredns-66f779496c-9m4cv          3m           13Mi
11etcd-node4                        36m          44Mi
12kube-apiserver-node4              147m         353Mi
13kube-controller-manager-node4     24m          49Mi
14kube-proxy-bt64z                  32m          26Mi
15kube-proxy-k4sft                  94m          25Mi
16kube-proxy-x28q9                  49m          17Mi
17kube-scheduler-node4              9m           18Mi
18metrics-server-7d686f4d9d-pgk6c   6m           17Mi
19tigera-operator-94d7f7696-nl5l7   3m           25Mi

接下来使用helm部署k8s的dashboard。当前k8s dashboard已经更新到了v3.0.0-alpha0,这里体验一下v3版本。

从k8s dashboard的v3版本开始,底层架构已更改,需要进行干净的安装,如果是在做升级dashboard操作,请首先移除先前的安装,这里是全新安装可以忽略。

k8s dashboard的v3版本现在默认使用cert-managernginx-ingress-controller。如果选择基于yaml清单的安装,请确保在集群中已安装它们。

我们前面已经安装了nginx-ingress-controller,下面先安装cert-manager:

1wget https://github.com/cert-manager/cert-manager/releases/download/v1.12.3/cert-manager.yaml
2
3kubectl apply -f cert-manager.yaml

确保cert-manager的所有pod启动正常:

1kubectl get po -n cert-manager
2NAME                                       READY   STATUS    RESTARTS   AGE
3cert-manager-6774cd657f-q9qpf              1/1     Running   0          102s
4cert-manager-cainjector-55c8b7b49b-vf8r4   1/1     Running   0          102s
5cert-manager-webhook-57797c469d-cgw4n      1/1     Running   0          102s

下载dashboard的yaml清单文件:

1wget https://raw.githubusercontent.com/kubernetes/dashboard/v3.0.0-alpha0/charts/kubernetes-dashboard.yaml

编辑kubernetes-dashboard.yaml清单文件,将其中的ingress中的host替换你的域名:

 1kind: Ingress
 2apiVersion: networking.k8s.io/v1
 3metadata:
 4  name: kubernetes-dashboard
 5  namespace: kubernetes-dashboard
 6  labels:
 7    app.kubernetes.io/name: nginx-ingress
 8    app.kubernetes.io/part-of: kubernetes-dashboard
 9  annotations:
10    nginx.ingress.kubernetes.io/ssl-redirect: "true"
11    cert-manager.io/issuer: selfsigned
12spec:
13  ingressClassName: nginx
14  tls:
15    - hosts:
16        - localhost
17      secretName: kubernetes-dashboard-certs
18  rules:
19    - host: k8s.example.com
20      http:
21        paths:
22          - path: /
23            pathType: Prefix
24            backend:
25              service:
26                name: kubernetes-dashboard-web
27                port:
28                  name: web
29          - path: /api
30            pathType: Prefix
31            backend:
32              service:
33                name: kubernetes-dashboard-api
34                port:
35                  name: api

安装dashboard的yaml清单文件:

1kubectl apply -f kubernetes-dashboard.yaml

确认dashboard的相关Pod启动正常:

1kubectl get po -n kubernetes-dashboard
2NAME                                                    READY   STATUS    RESTARTS   AGE
3kubernetes-dashboard-api-8586787f7-vtszr                1/1     Running   0          60s
4kubernetes-dashboard-metrics-scraper-6959b784dc-c98tz   1/1     Running   0          59s
5kubernetes-dashboard-web-6b6d549b4-qsrsn                1/1     Running   0          60s
6
7kubectl get ingress -n kubernetes-dashboard
8NAME                   CLASS   HOSTS             ADDRESS   PORTS     AGE
9kubernetes-dashboard   nginx   k8s.example.com             80, 443   6m47s

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。

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