K
Q

roles.rbac.authorization.k8s.io is forbidden even added in apiGroups

1/4/2019

I'm running kubernetes v1.11.5 and I'm installing helm with a tiller deployment for each namespace. Let's focus on a single namespace. This is the tiller service account configuration:

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: tiller
  namespace: marketplace-int
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tiller-manager
  namespace: marketplace-int
rules:
- apiGroups:
  - ""
  - extensions
  - apps
  - rbac.authorization.k8s.io
  - roles.rbac.authorization.k8s.io
  - authorization.k8s.io
  resources: ["*"]
  verbs: ["*"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tiller-binding
  namespace: marketplace-int
subjects:
- kind: ServiceAccount
  name: tiller
  namespace: marketplace-int
roleRef:
  kind: Role
  name: tiller-manager
  apiGroup: rbac.authorization.k8s.io

When I try to deploy a chart I get this error:

Error: release citest failed: roles.rbac.authorization.k8s.io "marketplace-int-role-ns-admin" is forbidden: 
attempt to grant extra privileges: 
[{[*] [*] [*] [] []}] user=&{system:serviceaccount:marketplace-int:tiller 5c6af739-1023-11e9-a245-0ab514dfdff4 
[system:serviceaccounts system:serviceaccounts:marketplace-int system:authenticated] map[]} 
ownerrules=[{[create] [authorization.k8s.io] [selfsubjectaccessreviews selfsubjectrulesreviews] [] []} 
{[get] [] [] [] [/api /api/* /apis /apis/* /healthz /openapi /openapi/* /swagger-2.0.0.pb-v1 /swagger.json /swaggerapi /swaggerapi/* /version /version/]} 
{[*] [ extensions apps rbac.authorization.k8s.io roles.rbac.authorization.k8s.io authorization.k8s.io] [*] [] []}] ruleResolutionErrors=[]

The error comes when trying to create rbac config for that namespace (with tiller sa):

# Source: marketplace/templates/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    app: citest
    chart: marketplace-0.1.0
    heritage: Tiller
    release: citest
    namespace: marketplace-int
  name: marketplace-int-role-ns-admin
rules:
  - apiGroups: ["*"]
    resources: ["*"]
    verbs: ["*"]

The error message clearly says that the tiller service account doesn't have permission for roles.rbac.authorization.k8s.io but that permission is granted as showed previously.

$kubectl describe role tiller-manager
Name:         tiller-manager
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"rbac.authorization.k8s.io/v1","kind":"Role","metadata":{"annotations":{},"name":"tiller-manager","namespace":"marketplace-i...
PolicyRule:
  Resources                          Non-Resource URLs  Resource Names  Verbs
  ---------                          -----------------  --------------  -----
  *                                  []                 []              [*]
  *.apps                             []                 []              [*]
  *.authorization.k8s.io             []                 []              [*]
  *.extensions                       []                 []              [*]
  *.rbac.authorization.k8s.io        []                 []              [*]
  *.roles.rbac.authorization.k8s.io  []                 []              [*]

Honestly, I don't fully understand the error message to check if the ownerrules are fine and I'm trying to find out what does it means this kind of messages that seems to be related with the role description: {[*] [*] [*] [] []}

Any clue about what permissions I am missing?

-- RuBiCK
kubernetes
kubernetes-helm
rbac

Similar Questions

GKE Cluster can't pull (ErrImagePull) from GCR Registry in same project (GitLab Kubernetes Integration): Why?
Large number of worker nodes v/s few worker nodes with more resources
Can we do chart installation in tiller instead of helm client?
Using minikube to pull image from local Docker registry (with self-signed CA certificate)
Getting Intermittent timeout on EKS when pods are running on multiple Nodes

3 Answers

1/4/2019

You should be able to create roles within that same namespace. I tried this myself, meaning creating a role using the same role that you described in your question and I was able to do it successfully (I changed my namespace to test), so I don't think it's related to your role definition but how tiller is using that specific service account to create new things.

# With an cluster-admin cluster role
$ echo '---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: tiller
  namespace: test
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tiller-manager
  namespace: test
rules:
- apiGroups:
  - ""
  - extensions
  - apps
  - rbac.authorization.k8s.io
  - roles.rbac.authorization.k8s.io
  - authorization.k8s.io
  resources: ["*"]
  verbs: ["*"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: tiller-binding
  namespace: test
subjects:
- kind: ServiceAccount
  name: tiller
  namespace: test
roleRef:
  kind: Role
  name: tiller-manager
  apiGroup: rbac.authorization.k8s.io' | kubectl apply -f -

Then:

$ kubectl -n test describe secret tiller-token-xxxxx
Name:         tiller-token-xxxx
Namespace:    test
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: tiller

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1025 bytes
namespace:  4 bytes
token:      <my-token>

Then:

$ mv ~/.kube ~/.kube.tmp
$ echo 'apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    app: citest
    chart: marketplace-0.1.0
    heritage: Tiller
    release: citest
  namespace: test
  name: marketplace-int-role-ns-admin
rules:
  - apiGroups: ["*"]
    resources: ["*"]
    verbs: ["*"]' | kubectl -n test --token <your-token> --server <your-kubeapiserver> apply -f - 
role.rbac.authorization.k8s.io/marketplace-int-role-ns-admin created
-- Rico
Source: StackOverflow
1/5/2019

This is due to permission escalation prevention in RBAC. See https://kubernetes.io/docs/reference/access-authn-authz/rbac/#privilege-escalation-prevention-and-bootstrapping for details.

Permission to create a role object is necessary, but not sufficient.

A user can only create/update a role if at least one of the following things is true:

  1. they already have all the permissions contained in the role, at the same scope as the object being modified (cluster-wide for a ClusterRole, within the same namespace or cluster-wide for a Role). In your case, that would mean the user attempting to create the role must already have apiGroups=*, resources=*, verbs=* permissions within the namespace where it is attempting to create the role. You can grant this by granting the cluster-admin clusterrole to the serviceaccount within that namespace with a rolebinding.

  2. they are given explicit permission to perform the "escalate" verb on the roles or clusterroles resource in the rbac.authorization.k8s.io API group (Kubernetes 1.12 and newer)

-- Jordan Liggitt
Source: StackOverflow
1/4/2019

First you need to give cluster-admin permission to tiller SA.

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: tiller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
  - kind: ServiceAccount
    name: tiller
    namespace: marketplace-int

Once you assign cluster-admin role to tiller SA, you should be able to create the role.

-- Sudhir
Source: StackOverflow