microk8s使用

在使用microk8s时，可以设置一些别名，使用起来保持与k8s习惯一样，具体如下

sudo snap alias microk8s.kubectl kubectl
sudo snap alias microk8s.ctr ctr
sudo snap alias microk8s.helm helm
sudo snap alias microk8s.helm3 helm3

部署microk8s后，排查集群状态

microk8s status
microk8s.inspect

docker-registry搭建私有镜像仓库

docker pull registry:2
docker create volume registry_data
mkdir  /opt/data/auth
docker run  --entrypoint htpasswd registry:2 -Bbn  admin  Harbor@dmin.mec > auth/htpasswd
docker run -d -p 5000:5000 --restart=always --name registry \
    -v registry_data:/var/lib/registry \
    -v /opt/data/auth:/auth \
    -e "REGISTRY_AUTH=htpasswd" \
    -e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
    -e  REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd \
    registry:2
docker login -u username -p userpasswd 192.168.1.33:5000    

保存镜像

docker save docker.io/calico/cni:v3.25.1 docker.io/calico/kube-controllers:v3.25.1 docker.io/calico/node:v3.25.1 docker.io/cdkbot/hostpath-provisioner:1.5.0 docker.io/coredns/coredns:1.10.1 docker.io/library/busybox:1.28.4 registry.k8s.io/ingress-nginx/controller:v1.8.0 registry.k8s.io/metrics-server/metrics-server:v0.6.3 registry.k8s.io/pause:3.7 -o microk8s.tar

导入镜像

microk8s ctr i import microk8s.tar

配置集群与访问

microk8s config > ~/.kube/config
kubectl get node -o wide
kubectl get pod -A

启用插件host-path和ingress-controller,metrics-server.

microk8s status
microk8s enable hostpath-storage
microk8s enable ingress
microk8s enable metrics-server

验证

kubectl get pod -A
microk8s status

资源占用量

root@xww-nuc8i5beh:/media/xww/sda1/server/microk8s# kubectl describe node
Name:               xww-nuc8i5beh
Roles:              <none>
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/os=linux
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=xww-nuc8i5beh
                    kubernetes.io/os=linux
                    microk8s.io/cluster=true
                    node.kubernetes.io/microk8s-controlplane=microk8s-controlplane
Annotations:        node.alpha.kubernetes.io/ttl: 0
                    projectcalico.org/IPv4Address: 192.168.10.102/24
                    projectcalico.org/IPv4VXLANTunnelAddr: 10.1.181.128
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Fri, 12 Jan 2024 20:24:04 +0800
Taints:             <none>
Unschedulable:      false
Lease:
  HolderIdentity:  xww-nuc8i5beh
  AcquireTime:     <unset>
  RenewTime:       Sat, 13 Jan 2024 11:12:38 +0800
Conditions:
  Type                 Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----                 ------  -----------------                 ------------------                ------                       -------
  NetworkUnavailable   False   Sat, 13 Jan 2024 11:01:36 +0800   Sat, 13 Jan 2024 11:01:36 +0800   CalicoIsUp                   Calico is running on this node
  MemoryPressure       False   Sat, 13 Jan 2024 11:09:49 +0800   Fri, 12 Jan 2024 20:24:04 +0800   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure         False   Sat, 13 Jan 2024 11:09:49 +0800   Fri, 12 Jan 2024 20:24:04 +0800   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure          False   Sat, 13 Jan 2024 11:09:49 +0800   Fri, 12 Jan 2024 20:24:04 +0800   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready                True    Sat, 13 Jan 2024 11:09:49 +0800   Sat, 13 Jan 2024 11:01:40 +0800   KubeletReady                 kubelet is posting ready status. AppArmor enabled
Addresses:
  InternalIP:  192.168.10.102
  Hostname:    xww-nuc8i5beh
Capacity:
  cpu:                8
  ephemeral-storage:  245084444Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             32867920Ki
  pods:               110
Allocatable:
  cpu:                8
  ephemeral-storage:  244035868Ki
  hugepages-1Gi:      0
  hugepages-2Mi:      0
  memory:             32765520Ki
  pods:               110
System Info:
  Machine ID:                 105c044a9dba42f5a4740ef13b5692eb
  System UUID:                B17F28E3-2822-F3FD-A1F3-94C691A75966
  Boot ID:                    6bac866c-d336-4606-9c47-6b01f110baef
  Kernel Version:             4.15.0-109-generic
  OS Image:                   Ubuntu 18.04.4 LTS
  Operating System:           linux
  Architecture:               amd64
  Container Runtime Version:  containerd://1.6.15
  Kubelet Version:            v1.28.3
  Kube-Proxy Version:         v1.28.3
Non-terminated Pods:          (6 in total)
  Namespace                   Name                                       CPU Requests  CPU Limits  Memory Requests  Memory Limits  AGE
  ---------                   ----                                       ------------  ----------  ---------------  -------------  ---
  kube-system                 calico-node-dp5tr                          250m (3%)     0 (0%)      0 (0%)           0 (0%)         14h
  kube-system                 calico-kube-controllers-77bd7c5b-fph2n     0 (0%)        0 (0%)      0 (0%)           0 (0%)         14h
  kube-system                 coredns-864597b5fd-n5pzq                   100m (1%)     0 (0%)      70Mi (0%)        170Mi (0%)     14h
  ingress                     nginx-ingress-microk8s-controller-z5plk    0 (0%)        0 (0%)      0 (0%)           0 (0%)         3m36s
  kube-system                 hostpath-provisioner-7df77bc496-q4zp6      0 (0%)        0 (0%)      0 (0%)           0 (0%)         3m36s
  kube-system                 metrics-server-848968bdcd-k5w78            100m (1%)     0 (0%)      200Mi (0%)       0 (0%)         3m35s
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource           Requests    Limits
  --------           --------    ------
  cpu                450m (5%)   0 (0%)
  memory             270Mi (0%)  170Mi (0%)
  ephemeral-storage  0 (0%)      0 (0%)
  hugepages-1Gi      0 (0%)      0 (0%)
  hugepages-2Mi      0 (0%)      0 (0%)
Events:              <none>

运行nginx进行测试

apiVersion: v1 #类型为Namespace
kind: Namespace  #类型为Namespace
metadata:
  name: ns-test  #命名空间名称
  labels:
    name: label-test  #pod标签
---
apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: ns-test
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:alpine
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  namespace: ns-test
  name: nginx-service
spec:
  selector:
    app: nginx
  type: NodePort
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30080

部署和验证

kubectl apply -f nginx.yaml
curl http://192.168.10.102:30080

部署有状态服务

# cat pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mypvc1
  namespace: ns-test
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: microk8s-hostpath

有状态的nginx服务

# cat nginx.yaml
apiVersion: v1 #类型为Namespace
kind: Namespace  #类型为Namespace
metadata:
  name: ns-test  #命名空间名称
  labels:
    name: label-test  #pod标签
---
apiVersion: apps/v1
kind: Deployment
metadata:
  namespace: ns-test
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:alpine
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: "/mydata"
          name: mydata
      volumes:
      - name: mydata
        persistentVolumeClaim:
          claimName: mypvc1
---
apiVersion: v1
kind: Service
metadata:
  namespace: ns-test
  name: nginx-service
spec:
  selector:
    app: nginx
  type: NodePort
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30080

验证

kubectl apply -f pvc.yaml
kubectl apply -f nginx.yaml
kubectl get pvc -A
kubectl get pod -A