creating-sample-user.md

Creating sample user

In this guide, we will find out how to create a new user using the Service Account mechanism of Kubernetes, grant this user admin permissions and login to Dashboard using a bearer token tied to this user.

For each of the following snippets for ServiceAccount and ClusterRoleBinding, you should copy them to new manifest files like dashboard-adminuser.yaml and use kubectl apply -f dashboard-adminuser.yaml to create them.

Creating a Service Account

We are creating Service Account with the name admin-user in namespace kubernetes-dashboard first.

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard

Creating a ClusterRoleBinding

In most cases after provisioning the cluster using kops, kubeadm or any other popular tool, the ClusterRole cluster-admin already exists in the cluster. We can use it and create only a ClusterRoleBinding for our ServiceAccount. If it does not exist then you need to create this role first and grant required privileges manually.

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

Getting a Bearer Token for ServiceAccount

Now we need to find the token we can use to log in. Execute the following command:

kubectl -n kubernetes-dashboard create token admin-user

It should print something like:

eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.Z2JrQlitASVwWbc-s6deLRFVk5DWD3P_vjUFXsqVSY10pbjFLG4njoZwh8p3tLxnX_VBsr7_6bwxhWSYChp9hwxznemD5x5HLtjb16kI9Z7yFWLtohzkTwuFbqmQaMoget_nYcQBUC5fDmBHRfFvNKePh_vSSb2h_aYXa8GV5AcfPQpY7r461itme1EXHQJqv-SN-zUnguDguCTjD80pFZ_CmnSE1z9QdMHPB8hoB4V68gtswR1VLa6mSYdgPwCHauuOobojALSaMc3RH7MmFUumAgguhqAkX3Omqd3rJbYOMRuMjhANqd08piDC3aIabINX6gP5-Tuuw2svnV6NYQ

Check Kubernetes docs for more information about API tokens for a ServiceAccount.

Getting a long-lived Bearer Token for ServiceAccount

We can also create a token with the secret which bound the service account and the token will be saved in the Secret:

apiVersion: v1
kind: Secret
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
  annotations:
    kubernetes.io/service-account.name: "admin-user"   
type: kubernetes.io/service-account-token  

After Secret is created, we can execute the following command to get the token which is saved in the Secret:

kubectl get secret admin-user -n kubernetes-dashboard -o jsonpath={".data.token"} | base64 -d

Check Kubernetes docs for more information about long-lived API tokens for a ServiceAccount.

Accessing Dashboard

Now copy the token and paste it into the Enter token field on the login screen.

Click the Sign in button and that's it. You are now logged in as an admin.

Note Token login is ONLY allowed when the browser is accessing the UI over https. If your networking path to the UI is via http, the login will fail with an invalid token error.

Clean up and next steps

Remove the admin ServiceAccount and ClusterRoleBinding.

kubectl -n kubernetes-dashboard delete serviceaccount admin-user
kubectl -n kubernetes-dashboard delete clusterrolebinding admin-user

In order to find out more about how to grant/deny permissions in Kubernetes read the official authentication & authorization documentation.

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Copyright 2020 The Kubernetes Dashboard Authors