创建虚拟机集群

VMware教程
VirtualBox教程
也可以在各大云供应商处购买几台服务器，比自己配置更省心

建议先创建一台虚拟机，安装好docker，k8s，以及需要的工具（curl，vim等）和镜像后再克隆成多个，节省在多个机器安装工具的步骤

安装docker

安装 K8s-v1.23 高可用集
需要阿里云ecs独立部署k8s集群的看这里
需要arm64架构方案的看这里

唯一要注意的就是ubuntu在20后已经用keyrings代替了原来的apt-key，网上很多教程的sudo curl -fsSL https://mirrors.aliyun.com/docker-ce/linux/ubuntu/gpg | sudo apt-key add -写法是无法正常工作的，不过Docker官方已经做出了正确示例
v

$ sudo apt-get update
$ sudo apt-get install ca-certificates curl gnupg lsb-release
$ sudo mkdir -p /etc/apt/keyrings
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
$ echo  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
$ sudo apt-get update
$ sudo apt-get install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin

kubernetes默认设置cgroup驱动(cgroupdriver)为"systemd"，而docker服务的cgroup驱动默认为"cgroupfs"，建议将其修改为"systemd"，与kubernetes保持一致，

除此之外这时还可以添加docker镜像和日志的配置

$ docker info # 用来查看cgroup
$ sudo vim /etc/docker/daemon.js
# 添加如下
# {
#  "registry-mirrors": ["https://ch72w18w.mirror.aliyuncs.com"],
#  "exec-opts": ["native.cgroupdriver=systemd"],
#  “log-driver”:“json-file”,
#  "log-opts": {"max-size":"100m", "max-file":"3"}
# }

配置后记得重启docker

sudo systemctl daemon-reload
sudo systemctl restart docker

安装k8s

$ curl -fsSL https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-archive-keyring.gpg
$ echo "deb [signed-by=/etc/apt/keyrings/kubernetes-archive-keyring.gpg] https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
$ sudo apt-get update
$ sudo apt-get install -y kubelet=1.21.14-00 kubeadm=1.21.14-00 kubectl=1.21.14-00

k8s v1.24后弃用dockershim，因此v1.24和之前的版本操作逻辑有很大区别，因此下载时最好提前明确指定版本。

拷贝并生成好几台虚拟机

右键 -> 复制

18.png

按照网络配置里记录的修改新机器的hostname和ip

为新机器生成新的密钥，并使用ssh-copy-id -i /home/<username1>/.ssh/id_rsa.pub <username2>@192.168..X.XXX将密钥分发给其他机器，如果都是root user可以使用ssh-copy-id 192.168.X.XXX

至此新的worker节点上应该：

1. 配置好了网络
2. 添加了ssh key
3. 安装了docker和k8s三件套

启动集群 【master节点】

k8s v1.24后弃用dockershim，因此v1.24和之前的版本操作逻辑有很大区别

启动k8s v1.21

启动k8s需要的镜像在国内很难下载，所以要预先查看需要的镜像

kubeadm config images list

并从阿里云拉取镜像并改名
需要注意coredns，k8s官方镜像比阿里云镜像多一层repo

docker pull registry.aliyuncs.com/google_containers/kube-apiserver:v1.21.14
docker pull registry.aliyuncs.com/google_containers/kube-controller-manager:v1.21.14
docker pull registry.aliyuncs.com/google_containers/kube-scheduler:v1.21.14
docker pull registry.aliyuncs.com/google_containers/kube-proxy:v1.21.14
docker pull registry.aliyuncs.com/google_containers/pause:3.4.1
docker pull registry.aliyuncs.com/google_containers/etcd:3.4.13-0
docker pull registry.aliyuncs.com/google_containers/coredns:v1.8.0

docker tag registry.aliyuncs.com/google_containers/kube-apiserver:v1.21.14 k8s.gcr.io/kube-apiserver:v1.21.14
docker tag registry.aliyuncs.com/google_containers/kube-controller-manager:v1.21.14 k8s.gcr.io/kube-controller-manager:v1.21.14
docker tag registry.aliyuncs.com/google_containers/kube-scheduler:v1.21.14 k8s.gcr.io/kube-scheduler:v1.21.14
docker tag registry.aliyuncs.com/google_containers/kube-proxy:v1.21.14 k8s.gcr.io/kube-proxy:v1.21.14
docker tag registry.aliyuncs.com/google_containers/pause:3.4.1 k8s.gcr.io/pause:3.4.1
docker tag registry.aliyuncs.com/google_containers/etcd:3.4.13-0 k8s.gcr.io/etcd:3.4.13-0
docker tag registry.aliyuncs.com/google_containers/coredns:v1.8.0 k8s.gcr.io/coredns/coredns:v1.8.0

预演启动集群，发现报错

$ kubeadm init phase preflight 
error execution phase preflight: [preflight] Some fatal errors occurred:
        [ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables does not exist
        [ERROR NumCPU]: the number of available CPUs 1 is less than the required 2
        [ERROR CRI]: container runtime is not running

第一个说明文件net.bridge.bridge-nf-call-iptables不存在，iptables 的 bridge traffic无法工作，通过如下配置修改

$ sudo modprobe br_netfilter
$ sudo sysctl net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-iptables = 1
$ cat /proc/sys/net/bridge/bridge-nf-call-iptables

第二个报错自行调整虚拟机CPU数量，第三个报错如下处理后重试

rm /etc/containerd/config.toml
systemctl restart containerd

preflight问题都解决后，重新正式启动

kubeadm init --kubernetes-version=v1.21.14  --image-repository registry.aliyuncs.com/google_containers --apiserver-advertise-address=192.168.1.111 --pod-network-cidr=10.244.0.0/12 --ignore-preflight-errors=Swap

kubeadm init报错解决 - 1

除了命令行里的flag之外，k8s官方现在比较推荐通过config file来配置参数

初始化参数模板可以用

kubeadm config print init-config.yml    # 初始化集群默认参数
kubeadm config print join-config.yml    # 加入集群默认参数
# 文件可以不带后缀，或者写成.conf, .yaml

参数的详细解释见这里

初始化时调用配置

kubeadm init --config init-config.yml

如果使用阿里云ecs且没有给容器配置公网IP，会造成初始化timeout的问题，解决方案可以看[这里](https://blog.csdn.net/weixin_47678667/article/details/121680938）

Bug

使用配置文件init时会有如下报错，但flag就不会

Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.884106  147373 eviction_manager.go:339] "Eviction manager: attempting to reclaim" resourceName="ephemeral-storage"
Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.884248  147373 container_gc.go:85] "Attempting to delete unused containers"
Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.913385  147373 image_gc_manager.go:321] "Attempting to delete unused images"
Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.944040  147373 eviction_manager.go:350] "Eviction manager: must evict pod(s) to reclaim" resourceName="ephemeral-storage"
Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.944706  147373 eviction_manager.go:368] "Eviction manager: pods ranked for eviction" pods=[kube-system/kube-apiserver-spinq-master kube-system/etcd-spinq-master kube-system/kube-controller-manager-spinq-master kube-system/kube-scheduler-spinq-master kube-system/kube-proxy-kk5qc kube-system/kube-flannel-ds-84l5f]
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.945299  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/kube-apiserver-spinq-master"
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.945719  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/etcd-spinq-master"
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.946068  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/kube-controller-manager-spinq-master"
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.946436  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/kube-scheduler-spinq-master"
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.946787  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/kube-proxy-kk5qc"
Feb 27 08:25:51 spinq-master kubelet[147373]: E0227 08:25:51.947147  147373 eviction_manager.go:560] "Eviction manager: cannot evict a critical pod" pod="kube-system/kube-flannel-ds-84l5f"
Feb 27 08:25:51 spinq-master kubelet[147373]: I0227 08:25:51.947488  147373 eviction_manager.go:391] "Eviction manager: unable to evict any pods from the node"

网上说是因为pod内部占用磁盘空间过多导致的，还没详细看透，参考资料如下

Kubernetes eviction manager evicting control plane pods to reclaim ephemeral storage

Node-pressure Eviction](https://kubernetes.io/docs/concepts/scheduling-eviction/node-pressure-eviction/)

成功的话会返回类似信息

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:                                                                            root:

kubeadm join 10.0.2.15:6443 --token fb4x67.zk0lses0315xvzla \
        --discovery-token-ca-cert-hash sha256:17167b1f9f4294d12766b1977681f0aa3575b9d978d371aa774fc5b9d978d371aa774fcadc707ff51d

按照指示配置kubeconfig，这样kubectl才可以查看到集群信息

普通user

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

root user

export KUBECONFIG=/etc/kubernetes/admin.conf

root user需要注意的是，如果选择了设置KUBECONFIG，这个环境变量只是暂时的，机器重启后kubectl会因为找不到KUBECONFIG而报如下错误

The connection to the server localhost:8080 was refused - did you specify the right host or port?

可以通过把export写进/etc/profile里解决

配置好后可以查看集群信息

cluster info.png

这时可以看到master node的状态是NotReady，需要按指示安装cni addon

重设token

kubadm生成的用来让worker join集群的token是24小时过期，隔天工作的时候需要重新查看和设置

查看token

kubeadm token list

如果token还未过期，可以进一步查看cert-hash

openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'

并拼接成命令供worker使用

kubeadm join 192.168.1.111:6443 --token <token>     --discovery-token-ca-cert-hash sha256:<cert-hash>

如果token已经过期了则需要重新生成

kubeadm token create --print-join-command

参考资料 K8S子节点加入集群Token查询及重新生成

flannel

因为资源容易被墙，先下载配置文件

wget https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml

然后按照预定的pod cidr决定是否修改参数net-conf.json

net-conf.json: |
    {
      "Network": "10.96.0.0/12",
      "Backend": {
        "Type": "vxlan"
      }
    }

然后将配置文件应用于集群

$ kubectl apply -f kube-flannel.yml
Warning: policy/v1beta1 PodSecurityPolicy is deprecated in v1.21+, unavailable in v1.25+
podsecuritypolicy.policy/psp.flannel.unprivileged created
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.apps/kube-flannel-ds created

可能发生如下状况

flannel-bug.png

这时需要查看出错pod的log

kubectl logs kube-flannel-ds-spw9v -n kube-system

如果遇到Error registering network: failed to acquire lease: node "spinq-master" pod cidr not assigned，说明：

1. pod cidr没有配置
2. pod cidr和kube-flannel.yml中的net-conf.json中的Network参数不一致

解决方法：

1. 如init集群时使用配置文件，则确认kube-init-config.yml中kind为ClusterConfiguration的配置中的networking中的podSubnet参数和kube-flannel.yml中的net-conf.json中的Network参数一致
2. 如init集群时使用命令行flag，则确认--pod-network-cidr和kube-flannel.yml中的net-conf.json中的Network参数一致

首次启动成功后flannel会创建两张虚拟网卡，cni0和flannel.1，且创建/etc/cni/net.d/10-flannel-conflist和/run/flannel/subnet.env

我做实验的时候kubeadm reset后etc/cni/net.d和/run下的cni文件不会自动删除，如果这时再重启集群，可能会导致node上的pod启动

kubeadm reset后网卡不会消失，/etc/cni/net.d/10-flannel-conflist和/run/flannel/subnet.env也不会消失，后续重启集群前如果不删除干净，可能会由于改变网络配置而导致集群通信失败

flannel创建网卡

可能导致的bug

Failed to create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "722424eeb5901d17fb90d720180f92a2683873110daccf82dc9c7e82f4ac665b" network for pod "coredns-59d64cd4d4-c7sm7": networkPlugin cni failed to set up pod "coredns-59d64cd4d4-c7sm7_kube-system" network: failed to delegate add: failed to set bridge addr: "cni0" already has an IP address different from 172.244.0.1/24

worker连接到master后也会有一样的网卡和配置文件，贸然删除网卡或配置文件的话也可能会导致worker连不上master的6443端口（curl https://<master-ip>:6443 failed），具体原因不明，重启后恢复正常

Calico

Calico的quickstart走的不是配置文件的途径，有些令人费解，希望用熟悉的配置文件方法配置的看这里

同样先下载配置文件

https://projectcalico.docs.tigera.io/getting-started/kubernetes/self-managed-onprem/onpremises

Calico的配置需要注意的是，calico-node默认访问kubernetes SVC的443端口，这将导致无法访问apiserver，需要在yaml文件添加apiserver的IP和端口

应用配置文件

kubectl apply -f calico.yaml

kubeadm 配置报错解决 - 1

安装cni addon成功后kubectl get nodes的结果会变成Ready

$ kubectl get nodes
NAME           STATUS   ROLES                  AGE    VERSION
spinq-master   Ready    control-plane,master   108m   v1.21.14

PS: calico不管是本地虚拟机还是阿里云ecs上启动都特别慢，教程一般说20s，但我都要等20分钟，不知道是内核资源调度原因还是下载资源的网络原因

PS: 如果使用kubeadm reset重置集群，会提示要删除/etc/cni/net.d中的cni配置，若删除了这个文件夹，则下一次kubeadm init会报错container network is not ready: cni config unitialized，就算再次运行kubectl apply -f calico.yaml也不一定会好，需要systemctl restart kubelet一下，感觉是因为自动更新机制有问题

可以通过kubectl get pods -A查看其状态，以及其他所有pod的状态

也可以通过docker ps查看不同功能的容器是否正常启动

PS：kubectl get cs的命令的scheduler和controller-manager在各种情况下都有可能为unhealthy，且已经在v1.19后弃用，因此不需要太担心详情

部署基于dockershim的k8s集群-1
部署基于dockershim的k8s集群-2

启动k8s v1.24

事先安装镜像

kubeadm config images pull --image-repository=registry.aliyuncs.com/google_containers

k8s v1.24后已经弃用dockershim，默认使用containerd，实际上使用的镜像要通过crictl img才能查看

ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/kube-apiserver:v1.24.2 k8s.gcr.io/kube-apiserver:v1.24.2
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/kube-controller-manager:v1.24.2 k8s.gcr.io/kube-controller-manager:v1.24.2
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/kube-scheduler:v1.24.2 k8s.gcr.io/kube-scheduler:v1.24.2
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/kube-proxy:v1.24.2 k8s.gcr.io/kube-proxy:v1.24.2
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/etcd:3.5.3-0 k8s.gcr.io/etcd:3.5.3-0
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/coredns:v1.8.6 k8s.gcr.io/coredns/coredns:v1.8.6

安装containerd和k8s v1.24 - 1
安装containerd和k8s v1.24 - 2

kubeadm init --kubernetes-version=v1.24.2  --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=192.168.0.0/16 --ignore-preflight-errors=Swap

kubelet可以开始运行，但是集群仍然报错

用systemctl status kubelet和journalctl -xeu kubelet查看日志，这里定位问题是需要一些耐心的

发现是包的版本问题，说明之前按照kubeadm config images list查看到的镜像也并非全部可靠

Jun 28 09:35:57 spinq-master kubelet[10593]: E0628 09:35:57.819736   10593 remote_runtime.go:201] "RunPodSandbox from runtime service failed" err="rpc error: code = Unknown desc = failed to get sandbox image \"k8s.gcr.io/pause:3.6\": failed to pull image \"k8s.gcr.io/pause:3.6\": failed to pull and unpack image \"k8s.gcr.io/pause:3.6\": failed to resolve reference \"k8s.gcr.io/pause:3.6\": failed to do request: Head \"https://k8s.gcr.io/v2/pause/manifests/3.6\": dial tcp 64.233.189.82:443: i/o timeout"

添加需要的包，有关于containerd的操作看这里

ctr -n k8s.io image pull registry.aliyuncs.com/google_containers/pause:3.6
ctr -n k8s.io image tag registry.aliyuncs.com/google_containers/pause:3.6 k8s.gcr.io/pause:3.6

17.png

添加节点 【worker节点】

使用init最后产生的命令将worker节点加入集群

$ kubeadm join 10.0.2.15:6443 --token fb4x67.zk0lses0315xvzla --discovery-token-ca-cert-hash sha256:17167b1f9f4294d12766b1977681f0aa3575b9d978d371aa774fc5b9d978d371aa774fcadc707ff51d
...
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

同样可以通过systemctl status kubelet和journalctl -xeu kubelet来监控节点是否成功启动，如果无法成功启动的话，大多数错误还是要去master上kubectl describe node或者pod来定位

部署服务

以部署一个nginx服务为例

k8s服务的基本架构 - 1
k8s服务的基本架构 - 2
k8s服务的基本架构 - 3

将下列配置写入master节点上的nginx-conf.yml文件

apiVersion: v1
kind: Namespace
metadata:
  name: nginx-demo

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-demo-deploy
  namespace: nginx-demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-tag
  template:
    metadata:
      labels:
        app: nginx-tag
    spec:
      containers:
      - name: nginx-ct
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80

---

apiVersion: v1
kind: Service
metadata:
  name: nginx-demo-service
  namespace: nginx-demo
spec:
  type: NodePort
  selector:
    app: nginx-tag # match the template metadata label in Deployment
  ports:
    - protocol: TCP
      port: 3088 # match for service access port
      targetPort: 80 # match for pod access port
      nodePort: 30088 # match for external access port

应用配置文件

$ kubectl apply -f nginx-conf.yml
namespace/nginx-demo unchanged
deployment.apps/nginx-demo-deploy created
service/nginx-demo-service configured

查看生成的pod，deployment，和service
注意kubectl get svc在不标注namesapce的情况下只显示defaultnamespace下的服务，因此一定要带-n参数

$ kubectl get pods -n nginx-demo -o wide
NAME                                 READY   STATUS    RESTARTS   AGE   IP            NODE            NOMINATED NODE   READINESS GATES
nginx-demo-deploy-784fb48fbc-kcjpl   1/1     Running   0          18s   10.240.1.11   spinq-worker1   <none>           <none>
nginx-demo-deploy-784fb48fbc-njw9n   1/1     Running   0          18s   10.240.1.10   spinq-worker1   <none>           <none>
$ kubectl get deploy -n nginx-demo
NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
nginx-demo-deploy   1/1     1            1           19s
$ kubectl get svc nginx-demo-service -n nginx-demo
NAME                 TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
nginx-demo-service   NodePort   10.109.6.66   <none>        3088:30008/TCP   23s

访问http://192.168.1.111:30088可以看到nginx的默认页面

nginx.png