kubernetes-1-k8s install DashBoard

1 Introduction to K8S Dashboard

K8S Dashboard is an official WEB-based user interface, specifically used to manage K8S clusters and display the status of the cluster. After the K8S cluster is installed, the Dashboard is not included by default, and you need to create it additionally.
The command to create kubernetes-dashboard is:

kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml

Note : There are many problems with the dashboard created directly in this way. The cluster built with kubeadm will enable RABC (Role Access Control Mechanism) by default, and additional settings must be made.

RBAC	Introduced in K8S 1.6, the authorization method for users to access k8S API resources [If you do not authorize, you are not eligible to access K8S resources]
user	K8S has two types of users: User and Service Account. User is for human use, and Service Account is for process, allowing the process to have relevant permissions. If Dashboard is a process, you can create a Service Account for it.
Character	Role is a collection of a series of permissions, for example, a Role can contain the permissions to read and list Pods [ClusterRole is similar to Role, and its scope of permissions is the entire cluster]
Role binding	RoleBinding maps roles to users, so that these users have the permissions of the role [ClusterRoleBinding is similar to RoleBinding, allowing users to have the permissions of ClusterRole]
Secret	Secret is an object that contains a small amount of sensitive information such as passwords, tokens, or secret keys. Storing this information in the Secret object can control the information when it is used and reduce the risk of information leakage.

2 Official kubernetes-dashboard.yaml

download:

wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml

File kubernetes-dashboard.yaml.

# Configuration to deploy release version of the Dashboard UI compatible with
# Kubernetes 1.8.
#
# Example usage: kubectl create -f <this_file>

# ------------------- Dashboard Secret ------------------- #

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque

---
# ------------------- Dashboard Service Account ------------------- #

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Role & Role Binding ------------------- #

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
rules:
  # Allow Dashboard to create 'kubernetes-dashboard-key-holder' secret.
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["create"]
  # Allow Dashboard to create 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["create"]
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
- apiGroups: [""]
  resources: ["secrets"]
  resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs"]
  verbs: ["get", "update", "delete"]
  # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["kubernetes-dashboard-settings"]
  verbs: ["get", "update"]
  # Allow Dashboard to get metrics from heapster.
- apiGroups: [""]
  resources: ["services"]
  resourceNames: ["heapster"]
  verbs: ["proxy"]
- apiGroups: [""]
  resources: ["services/proxy"]
  resourceNames: ["heapster", "http:heapster:", "https:heapster:"]
  verbs: ["get"]

---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard-minimal
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Deployment ------------------- #

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        imagePullPolicy: IfNotPresent
        image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          - --auto-generate-certificates
          # Uncomment the following line to manually specify Kubernetes API server Host
          # If not specified, Dashboard will attempt to auto discover the API server and connect
          # to it. Uncomment only if the default does not work.
          # - --apiserver-host=http://my-address:port
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
          # Create on-disk volume to store exec logs
        - mountPath: /tmp
          name: tmp-volume
        livenessProbe:
          httpGet:
            scheme: HTTPS
            path: /
            port: 8443
          initialDelaySeconds: 30
          timeoutSeconds: 30
      volumes:
      - name: kubernetes-dashboard-certs
        secret:
          secretName: kubernetes-dashboard-certs
      - name: tmp-volume
        emptyDir: {
    
    }
      serviceAccountName: kubernetes-dashboard
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      nodePort: 32000
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard

2.1 Dashboard Secret

# Configuration to deploy release version of the Dashboard UI compatible with
# Kubernetes 1.8.
#
# Example usage: kubectl create -f <this_file>

# ------------------- Dashboard Secret ------------------- #

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque

2.2 Dashboard Service Account

---
# ------------------- Dashboard Service Account ------------------- #

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system

The user of the Dashboard is defined as above, the type is ServiceAccount, and the name is kubernetes-dashboard.

2.3 Dashboard Role

---
# ------------------- Dashboard Role & Role Binding ------------------- #

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
rules:
  # Allow Dashboard to create 'kubernetes-dashboard-key-holder' secret.
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["create"]
  # Allow Dashboard to create 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["create"]
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
- apiGroups: [""]
  resources: ["secrets"]
  resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs"]
  verbs: ["get", "update", "delete"]
  # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["kubernetes-dashboard-settings"]
  verbs: ["get", "update"]
  # Allow Dashboard to get metrics from heapster.
- apiGroups: [""]
  resources: ["services"]
  resourceNames: ["heapster"]
  verbs: ["proxy"]
- apiGroups: [""]
  resources: ["services/proxy"]
  resourceNames: ["heapster", "http:heapster:", "https:heapster:"]
  verbs: ["get"]

The role of Dashboard is defined as above. Its role name is kubernetes-dashboard-minimal, and its multiple permissions are clearly listed in the rules. From the name, we can guess that this permission level is relatively low.

2.4 Role Binding

---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard-minimal
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

The role binding of Dashboard is defined as above, and its name is kubernetes-dashboard-minimal, roleRef is the bound role, also called kubernetes-dashboard-minimal, and subjects is the bound user: kubernetes-dashboard.

Dashboard configuration is difficult, especially when it comes to security permissions, which is quite complicated and has many pitfalls. After entering the login interface of Dashboard, there are two authentication methods: Kubeconfig and token (in fact, there are also account password methods, which are not turned on by default and do not display). Seeing Kubeconfig and the token, it is estimated that the head is big. Is there an easy way for us to directly access the Dashboard? Of course, if you choose to skip it, the following page will appear:
as shown in the figure above, unfortunately, we have seen a lot of permission error prompts, mainly caused by insufficient permissions of system:serviceaccount:kube-system:kubernetes-dashboard.
Now I understand why its role is named kubernetes-dashboard-minimal. In a word, the permissions of this Role are not enough!
Therefore, we can change the RoleBinding to ClusterRoleBinding, and modify the kind and name in the roleRef, using cluster-admin, a very awesome CusterRole (super user permission, which has all the permissions to access kube-apiserver). as follows:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard-admin
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

2.4 Dashboard Deployment

---
# ------------------- Dashboard Deployment ------------------- #

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        imagePullPolicy: IfNotPresent
        image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          - --auto-generate-certificates
          # Uncomment the following line to manually specify Kubernetes API server Host
          # If not specified, Dashboard will attempt to auto discover the API server and connect
          # to it. Uncomment only if the default does not work.
          # - --apiserver-host=http://my-address:port
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
          # Create on-disk volume to store exec logs
        - mountPath: /tmp
          name: tmp-volume
        livenessProbe:
          httpGet:
            scheme: HTTPS
            path: /
            port: 8443
          initialDelaySeconds: 30
          timeoutSeconds: 30
      volumes:
      - name: kubernetes-dashboard-certs
        secret:
          secretName: kubernetes-dashboard-certs
      - name: tmp-volume
        emptyDir: {
    
    }
      serviceAccountName: kubernetes-dashboard
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule

As you can see above, Dashboard's Deployment specifies that the ServiceAccount it uses is kubernetes-dashboard. And also hang Secret kubernetes-dashboard-certs to the /certs path inside the pod through volumes. Why mount Secret? The reason is that the token is automatically generated when the Secret is created. Please pay attention to the parameter -auto-generate-certificates, which means that Dashboard will automatically generate certificates.

2.5 Dashboard Service

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      nodePort: 32000
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard

3 Edited kubernetes-dashboard.yaml

# Configuration to deploy release version of the Dashboard UI compatible with
# Kubernetes 1.8.
#
# Example usage: kubectl create -f <this_file>

# ------------------- Dashboard Secret ------------------- #

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque

---
# ------------------- Dashboard Service Account ------------------- #

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Role Binding ------------------- #

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard-admin
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Deployment ------------------- #

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
      - name: kubernetes-dashboard
        imagePullPolicy: IfNotPresent
        image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          - --auto-generate-certificates
          # Uncomment the following line to manually specify Kubernetes API server Host
          # If not specified, Dashboard will attempt to auto discover the API server and connect
          # to it. Uncomment only if the default does not work.
          # - --apiserver-host=http://my-address:port
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
          # Create on-disk volume to store exec logs
        - mountPath: /tmp
          name: tmp-volume
        livenessProbe:
          httpGet:
            scheme: HTTPS
            path: /
            port: 8443
          initialDelaySeconds: 30
          timeoutSeconds: 30
      volumes:
      - name: kubernetes-dashboard-certs
        secret:
          secretName: kubernetes-dashboard-certs
      - name: tmp-volume
        emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      nodePort: 32000
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard

4 Install dashboard

Just place the mirror k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3 on the worker node.

#docker save -o k8s.gcr.io_kubernetes-dashboard-amd64_v1.8.3.tar k8s.gcr.io/kubernetes-dashboard-amd64:v1.8.3

(1) Perform installation

# kubectl apply -f kubernetes-dashboard.yaml

(2) Get dashboard administrator role token
#kubectl get secret -n kube-system | grep dashboard
#kubectl describe secret -n kube-system kubernetes-dashboard-token-ml4lg
#kubectl describe secret -n kube-system kubernetes-dashboard

https://10.23.241.97:32000
Copy the token to the token without spaces .