diff --git a/docs/service_accounts.md b/docs/service_accounts.md index 19a2e2cb614e0cde14f5e418e808bc29fcfad0bc..612074d03548ddad376bb6b33189bc7e8162fe3c 100644 --- a/docs/service_accounts.md +++ b/docs/service_accounts.md @@ -1,39 +1,112 @@ # Tiller and Service Accounts -In Kubernetes, granting a role to an application-specific service account is a best practice to ensure that your application is operating in the scope that you have specified. Read more about service account permissions in Kubernetes [here](https://kubernetes.io/docs/admin/authorization/rbac/#service-account-permissions). +In Kubernetes, granting a role to an application-specific service account is a best practice to ensure that your application is operating in the scope that you have specified. Read more about service account permissions [in the official Kubernetes docs](https://kubernetes.io/docs/admin/authorization/rbac/#service-account-permissions). Bitnami also has a fantastic guide for [configuring RBAC in your cluster](https://docs.bitnami.com/kubernetes/how-to/configure-rbac-in-your-kubernetes-cluster/) that takes you through RBAC basics. You can add a service account to Tiller using the `--service-account <NAME>` flag while you're configuring helm. As a prerequisite, you'll have to create a role binding which specifies a [role](https://kubernetes.io/docs/admin/authorization/rbac/#role-and-clusterrole) and a [service account](https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/) name that have been set up in advance. Once you have satisfied the pre-requisite and have a service account with the correct permissions, you'll run a command like this: `helm init --service-account <NAME>` -## Example +## Example: Service account with cluster-admin role + +```console +$ kubectl create serviceaccount tiller --namespace kube-system +``` In `rbac-config.yaml`: ```yaml apiVersion: v1 kind: ServiceAccount metadata: - name: helm + name: tiller namespace: kube-system --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRoleBinding metadata: - name: helm + name: tiller roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: cluster-admin subjects: - kind: ServiceAccount - name: helm + name: tiller namespace: kube-system ``` +_Note: The cluster-admin role is created by default in a Kubernetes cluster, so you don't have to define it explicitly._ ```console $ kubectl create -f rbac-config.yaml -$ helm init --service-account helm +$ helm init --service-account tiller +``` + +## Example: Service account restricted to a namespace +In the example above, we gave Tiller admin access to the entire cluster. You are not at all required to give Tiller cluster-admin access for it to work. Instead of specifying a ClusterRole or a ClusterRoleBinding, you can specify a Role and RoleBinding to limit Tiller's scope to a particular namespace. + +```console +$ kubectl create namespace tiller-world +namespace "tiller-world" created +$ kubectl create serviceaccount tiller --namespace tiller-world +serviceaccount "tiller" created +``` + +Define a Role like in `role-tiller.yaml`: +```yaml +kind: Role +apiVersion: rbac.authorization.k8s.io/v1beta1 +metadata: + namespace: tiller-world + name: tiller-manager +rules: +- apiGroups: ["", "extensions", "apps"] + resources: ["deployments", "replicasets", "pods", "configmaps", "secrets", "namespaces"] + verbs: ["get", "list", "watch", "create", "update", "patch", "delete"] # You can also use ["*"] +``` + +```console +$ kubectl create -f role-tiller.yaml +role "tiller-manager" created +``` + +In `rolebinding-tiller.yaml`, +```yaml +kind: RoleBinding +apiVersion: rbac.authorization.k8s.io/v1beta1 +metadata: + name: tiller-binding + namespace: tiller-world +subjects: +- kind: ServiceAccount + name: tiller + namespace: tiller-world +roleRef: + kind: Role + name: tiller-manager + apiGroup: rbac.authorization.k8s.io +``` + +```console +$ kubectl create -f rolebinding-tiller.yaml +rolebinding "tiller-binding" created +``` + +```console +$ helm init --service-account tiller --tiller-namespace tiller-world +$HELM_HOME has been configured at /Users/awesome-user/.helm. + +Tiller (the helm server side component) has been installed into your Kubernetes Cluster. +Happy Helming! + +$ helm install nginx --tiller-namespace tiller-world --namespace tiller-world +NAME: wayfaring-yak +LAST DEPLOYED: Mon Aug 7 16:00:16 2017 +NAMESPACE: tiller-world +STATUS: DEPLOYED + +RESOURCES: +==> v1/Pod +NAME READY STATUS RESTARTS AGE +wayfaring-yak-alpine 0/1 ContainerCreating 0 0s ``` -_Note: You do not have to specify a ClusterRole or a ClusterRoleBinding. You can specify a Role and RoleBinding instead to limit Tiller's scope to a particular namespace_