Role-Based Access Control

Role-Based Access Control (RBAC) lets you restrict access to resources and actions to specified users or groups, based on user roles.

How it works

Kong Mesh provides two resources to implement RBAC:

AccessRole specifies kinds of access and resources to which access is granted. Note that access is defined only for write operations. Read access is available to all users.
AccessRoleBinding lists users and the access roles that are assigned to them.

AccessRole

AccessRole defines a role that is assigned separately to users. It is global-scoped, which means it is not bound to a mesh.

Source and Destination selectors

`targetRef` selectors

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: role-1
spec:
  rules:
  - types: ["TrafficPermission", "TrafficRoute", "Mesh"] # list of types to which access is granted. If empty, then access is granted to all types
    names: ["res-1"] # list of allowed names of types to which access is granted. If empty, then access is granted to resources regardless of the name.
    mesh: default # Mesh within which the access to resources is granted. It can only be used with the Mesh-scoped resources.
    access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"] # an action that is bound to a type.
    when: # a set of qualifiers to receive an access. Only one of them needs to be fulfilled to receive an access
    - sources: # a condition on sources section in connection policies (like TrafficRoute or Healtchecheck). If missing, then all sources are allowed
        match:
          kuma.io/service: web
      destinations: # a condition on destinations section in connection policies (like TrafficRoute or Healtchecheck). If missing, then all destinations are allowed
        match:
          kuma.io/service: backend
    - selectors: # a condition on selectors section in dataplane policies (like TrafficTrace or ProxyTemplate).
        match:
          kuma.io/service: web
    - dpToken: # a condition on generate dataplane token.
        tags:
        - name: kuma.io/service
          value: web

type: AccessRole
name: role-1
rules:
- types: ["TrafficPermission", "TrafficRoute", "Mesh"] # list of types to which access is granted. If empty, then access is granted to all types
  names: ["res-1"] # list of allowed names of types to which access is granted. If empty, then access is granted to resources regardless of the name.
  mesh: default # Mesh within which the access to resources is granted. It can only be used with the Mesh-scoped resources.
  access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"] # an action that is bound to a type.
  when: # a set of qualifiers to receive an access. Only one of them needs to be fulfilled to receive an access
  - sources: # a condition on sources section in connection policies (like TrafficRoute or Healtchecheck). If missing, then all sources are allowed
      match:
        kuma.io/service: web
    destinations: # a condition on destinations section in connection policies (like TrafficRoute or Healtchecheck). If missing, then all destinations are allowed
      match:
        kuma.io/service: backend
  - selectors: # a condition on selectors section in dataplane policies (like TrafficTrace or ProxyTemplate).
      match:
        kuma.io/service: web
  - dpToken: # a condition on generate dataplane token.
      tags:
      - name: kuma.io/service
        value: web

For policies using the targetRef selector. You can specify which targetRef kinds users should have access to.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: role-1
spec:
  rules:
  - types: ["MeshTrafficPermission", "MeshTrace", "MeshAccessLog"] # List of types that are granted access. If it's empty, access is granted to all types.
    names: ["res-1"] # List of allowed type names that are granted access. If it's empty, access is granted to resources regardless of the name.
    mesh: default # Grants access to the resources in the named mesh. It can only be used with the mesh-scoped resources.
    access: ["CREATE", "UPDATE", "DELETE"] # The action bound to a type.
    when: # A set of qualifiers to receive access. Only one of them needs to be fulfilled to receive access.
    - tagetRef: # A condition on the targetRef section in policies 2.0 (like MeshAccessLog or MeshTrace).
        kind: MeshService
        name: backend
    - targetRef:
        kind: MeshSubset
        tags:
        - name: k8s.kuma.io/namespace
          value: kuma-demo
    - targetRef:
        kind: MeshService
        name: web
      to: # can only be used with policies that have a "to" list (like MeshAccessLog)
        targetRef:
          kind: MeshService
          name: backend
    - targetRef:
        kind: MeshService
        name: web
      from: # can only be used with policies that have a "from" list (like MeshTrafficPermission)
        targetRef:
          kind: Mesh

type: AccessRole
name: role-1
rules:
- types: ["MeshTrafficPermission", "MeshTrace", "MeshAccessLog"] # List of types that are granted access. If it's empty, access is granted to all types.
  names: ["res-1"] # List of allowed type names that are granted access. If it's empty, access is granted to resources regardless of the name.
  mesh: default # Grants access to the resources in the named mesh. It can only be used with the mesh-scoped resources.
  access: ["CREATE", "UPDATE", "DELETE"] # The action bound to a type.
  when: # A set of qualifiers to receive access. Only one of them needs to be fulfilled to receive access.
  - tagetRef: # A condition on the targetRef section in policies 2.0 (like MeshAccessLog or MeshTrace).
        kind: MeshService
        name: backend
  - targetRef:
      kind: MeshSubset
      tags:
      - name: k8s.kuma.io/namespace
        value: kuma-demo
  - targetRef:
      kind: MeshService
      name: web
    to: # can only be used with policies that have a "to" list (like MeshAccessLog)
      targetRef:
        kind: MeshService
        name: backend
  - targetRef:
      kind: MeshService
      name: web
    from: # can only be used with policies that have a "from" list (like MeshTrafficPermission)
      targetRef:
        kind: Mesh

The lack of targetRef, from, or to means that a user can specify anything in this section. For example, the when element with a specific from section allows the user to pick anything for targetRef in the policy. If the policy contains multiple to elements, you must specify an RBAC qualifier for every single to element.

AccessRoleBinding

AccessRoleBinding assigns a set of AccessRoles to a set of subjects (users and groups). It is global-scoped, which means it is not bound to a mesh.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: binding-1
spec:
  subjects: # a list of subjects that will be assigned roles
  - type: User # type of the subject. Available values: ("User", "Group")
    name: john.doe@example.com # name of the subject.
  - type: Group
    name: team-a
  roles: # a list of roles that will be assigned to the list of subjects.
  - role-1

type: AccessRoleBinding
name: binding-1
subjects: # a list of subjects that will be assigned roles
- type: User # type of the subject. Available values: ("User", "Group")
  name: john.doe@example.com # name of the subject.
- type: Group
  name: team-a
roles: # a list of roles that will be assigned to the list of subjects.
- role-1

Example roles

Let’s go through example roles in the organization that can be created using Kong Mesh RBAC.

Kong Mesh operator (admin)

Mesh operator is a part of infrastructure team responsible for Kong Mesh deployment.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: admin
spec:
  rules:
  - access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"]

type: AccessRole
name: admin
rules:
- access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"]

This way Kong Mesh operators can execute any action.

Note: This role is automatically created on the start of the control plane.

Service owner

Service owner is a part of team responsible for given service. Let’s take a backend service as an example.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: backend-owner
spec:
  rules:
    - mesh: default
      types: ["TrafficPermission", "RateLimit"]
      access: ["CREATE", "DELETE", "UPDATE"]
      when:
        - destinations:
            match:
              kuma.io/service: backend
    - mesh: default
      types: ["TrafficRoute", "HealthCheck", "CircuitBreaker", "FaultInjection", "Retry", "Timeout", "TrafficLog"]
      access: ["CREATE", "DELETE", "UPDATE"]
      when:
        - sources:
            match:
              kuma.io/service: backend
        - destinations:
            match:
              kuma.io/service: backend
    - mesh: default
      types: ["TrafficTrace", "ProxyTemplate"]
      access: ["CREATE", "DELETE", "UPDATE"]
      when:
        - selectors:
            match:
              kuma.io/service: backend

type: AccessRole
name: backend-owner
rules:
- mesh: default
  types: ["TrafficPermission", "RateLimit"]
  access: ["CREATE", "DELETE", "UPDATE"]
  when:
  - destinations:
      match:
        kuma.io/service: backend
- mesh: default
  types: ["TrafficRoute", "HealthCheck", "CircuitBreaker", "FaultInjection", "Retry", "Timeout", "TrafficLog"]
  access: ["CREATE", "DELETE", "UPDATE"]
  when:
  - sources:
      match:
        kuma.io/service: backend
  - destinations:
      match:
        kuma.io/service: backend
- mesh: default
  types: ["TrafficTrace", "ProxyTemplate"]
  access: ["CREATE", "DELETE", "UPDATE"]
  when:
  - selectors:
      match:
        kuma.io/service: backend

This way a service owners can:

Modify RateLimit and TrafficPermission that allows/restrict access to the backend service. This changes the configuration of data plane proxy that implements backend service.
Modify connection policies (TrafficRoute, HealthCheck, CircuitBreaker, FaultInjection, Retry, Timeout, RateLimit, TrafficLog) that matches backend service that connects to other services. This changes the configuration of data plane proxy that implements backend service.
Modify connection policies that matches any service that consumes backend service. This changes the configuration of data plane proxies that are connecting to backend, but the configuration only affects connections to backend service. It’s useful because the service owner of backend has the best knowledge what (Timeout, HealthCheck) should be applied when communicating with their service.
Modify TrafficTrace or ProxyTemplate that matches backend service. This changes the configuration of data plane proxy that implements backend service.

Note: When giving users UPDATE permission, remember to add UPDATE permission to all selectors they can switch between. For example, if a user only has access to sources selector, they won’t be able to update policy with destinations selector or new targetRef selectors. Likewise, when a user only has access to the targetRef kind MeshService, they won’t be able to update the policy to use a different targetRef kind.

Observability operator

We may also have an infrastructure team which is responsible for the logging/metrics/tracing systems in the organization. Currently, those features are configured on Mesh, TrafficLog and TrafficTrace objects.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: observability-operator
spec:
  rules:
    - mesh: '*'
      types: ["TrafficLog", "TrafficTrace"]
      access: ["CREATE", "DELETE", "UPDATE"]
    - types: ["Mesh"]
      access: ["CREATE", "DELETE", "UPDATE"]

type: AccessRole
name: observability-operator
rules:
- mesh: '*'
  types: ["TrafficLog", "TrafficTrace"]
  access: ["CREATE", "DELETE", "UPDATE"]
- types: ["Mesh"]
  access: ["CREATE", "DELETE", "UPDATE"]

This way an observability operator can:

Modify TrafficLog and TrafficTrace in any mesh
Modify any Mesh

Single Mesh operator

Kong Mesh lets us segment the deployment into many logical service meshes configured by Mesh object. We may want to give an access to one specific Mesh and all objects connected with this Mesh.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: demo-mesh-operator
spec:
  rules:
    - mesh: demo
      access: ["CREATE", "DELETE", "UPDATE"]
    - types: ["Mesh"]
      names: ["demo"]
      access: ["CREATE", "DELETE", "UPDATE"]

type: AccessRole
name: demo-mesh-operator
rules:
- mesh: demo
  access: ["CREATE", "DELETE", "UPDATE"]
- types: ["Mesh"]
  names: ["demo"]
  access: ["CREATE", "DELETE", "UPDATE"]

This way all observability operator can:

Modify all resources in the demo mesh
Modify demo Mesh object.

Kubernetes

Kubernetes provides their own RBAC system, but it’s not sufficient to cover use cases for several reasons:

You cannot restrict an access to resources of specific Mesh
You cannot restrict an access based on the content of the policy

Kong Mesh RBAC works on top of Kubernetes RBAC. For example, to restrict the access for a user to modify TrafficPermission for backend service, they need to be able to create TrafficPermission in the first place.

The subjects in AccessRoleBinding are compatible with Kubernetes users and groups. Kong Mesh RBAC on Kubernetes is implemented using Kubernetes Webhook when applying resources. This means you can only use Kubernetes users and groups for CREATE, DELETE and UPDATE access. GENERATE_DATAPLANE_TOKEN, GENERATE_USER_TOKEN, GENERATE_ZONE_CP_TOKEN, GENERATE_ZONE_TOKEN are used when interacting with Kong Mesh API Server, in this case you need to use the user token.

Default

Kong Mesh creates an admin AccessRole that allows every action.

In a standalone deployment, the default AccessRoleBinding assigns this role to every authenticated and unauthenticated user.

In a multi-zone deployment, the default AccessRoleBinding on the global control plane assigns this role to every authenticated and unauthenticated user. However, on the zone control plane, the default AccessRoleBinding is restricted to the admin AccessRole only.

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: admin
spec:
  rules:
  - access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"]
---
apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: default
spec:
  subjects:
  - type: Group
    name: mesh-system:authenticated
  - type: Group
    name: mesh-system:unauthenticated
  - type: Group
    name: system:authenticated
  - type: Group
    name: system:unauthenticated
  roles:
  - admin

type: AccessRole
name: admin
rules:
- access: ["CREATE", "UPDATE", "DELETE", "GENERATE_DATAPLANE_TOKEN", "GENERATE_USER_TOKEN", "GENERATE_ZONE_CP_TOKEN", "GENERATE_ZONE_TOKEN"]
---
type: AccessRoleBinding
name: default
subjects:
- type: Group
  name: mesh-system:authenticated
- type: Group
  name: mesh-system:unauthenticated
roles:
- admin

To restrict access to admin only, change the default AccessRole policy:

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: default
spec:
  subjects:
  - type: Group
    name: mesh-system:admin
  - type: Group
    name: system:masters
  - type: Group
    name: system:serviceaccounts:kube-system
  roles:
  - admin

system:serviceaccounts:kube-system is required for Kubernetes controllers to manage Kong Mesh resources – for example, to remove data plane objects when a namespace is removed.

type: AccessRoleBinding
name: default
subjects:
- type: Group
  name: mesh-system:admin
roles:
- admin

Example

Here are the steps to create a new user and restrict the access only to TrafficPermission for backend service.

Source and Destination selectors

`targetRef` selectors

Kubernetes

Universal

Create a backend-owner Kubernetes user and configure kubectl:

mkdir -p /tmp/k8s-certs
cd /tmp/k8s-certs
openssl genrsa -out backend-owner.key 2048 # generate client key
openssl req -new -key backend-owner.key -subj "/CN=backend-owner" -out backend-owner.csr # generate client certificate request
CSR=$(cat backend-owner.csr | base64 | tr -d "\n") && echo "apiVersion: certificates.k8s.io/v1
kind: CertificateSigningRequest
metadata:
  name: backend-owner
spec:
  request: $CSR
  signerName: kubernetes.io/kube-apiserver-client
  usages:
  - client auth" | kubectl apply -f -
kubectl certificate approve backend-owner
kubectl get csr backend-owner -o jsonpath='{.status.certificate}'| base64 -d > backend-owner.crt
kubectl config set-credentials backend-owner \
--client-key=/tmp/k8s-certs/backend-owner.key \
--client-certificate=/tmp/k8s-certs/backend-owner.crt \
--embed-certs=true
kubectl config set-context backend-owner --cluster=YOUR_CLUSTER_NAME --user=backend-owner

Create Kubernetes RBAC to allow backend-owner to manage all TrafficPermission:

echo "
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: kuma-policy-management
rules:
- apiGroups:
  - kuma.io
  resources:
  - trafficpermissions
  verbs:
  - get
  - list
  - watch
  - create
  - update
  - patch
  - delete
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kuma-policy-management-backend-owner
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kuma-policy-management
subjects:
- kind: User
  name: backend-owner
  apiGroup: rbac.authorization.k8s.io
" | kubectl apply -f -

Change default Kong Mesh RBAC to restrict access to resources by default:

echo "
apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: default
spec:
  subjects:
  - type: Group
    name: mesh-system:admin
  - type: Group
    name: system:masters
  - type: Group
    name: system:serviceaccounts:kube-system
  roles:
  - admin
" | kubectl apply -f -

Create an AccessRole to grant permissions to user backend-owner to modify TrafficPermission only for the backend service:

echo '
---
apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: backend-owner
spec:
  rules:
  - types: ["TrafficPermission"]
    mesh: default
    access: ["CREATE", "UPDATE", "DELETE"]
    when:
    - destinations:
        match:
          kuma.io/service: backend
---
apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: backend-owners
spec:
  subjects:
  - type: User
    name: backend-owner
  roles:
  - backend-owner
' | kubectl apply -f -

Change the service to test user access:

kubectl config use-context backend-owner
echo "
apiVersion: kuma.io/v1alpha1
kind: TrafficPermission
mesh: default
metadata:
  name: web-to-backend
spec:
  sources:
    - match:
        kuma.io/service: web
  destinations:
    - match:
        kuma.io/service: backend
" | kubectl apply -f -
# operation should succeed, access to backend service access is granted

echo "
apiVersion: kuma.io/v1alpha1
kind: TrafficPermission
mesh: default
metadata:
  name: web-to-backend
spec:
  sources:
    - match:
        kuma.io/service: web
  destinations:
    - match:
        kuma.io/service: not-backend # access to this service is not granted
" | kubectl apply -f -
# operation should not succeed

Note: By default, all requests that originates from localhost are authenticated as user admin belonging to group mesh-system:admin. In order for this example to work you must either run the control plane with KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN set to false or be accessing the control plane not via localhost.

Extract admin token and configure kumactl with admin:

export ADMIN_TOKEN=$(curl http://localhost:5681/global-secrets/admin-user-token | jq -r .data | base64 -d)
kumactl config control-planes add \
--name=cp-admin \
--address=https://localhost:5682 \
--skip-verify=true \
--auth-type=tokens \
--auth-conf token=$ADMIN_TOKEN

Configure backend-owner:

export BACKEND_OWNER_TOKEN=$(kumactl generate user-token --valid-for=24h --name backend-owner)
kumactl config control-planes add \
--name=cp-backend-owner \
--address=https://localhost:5682 \
--skip-verify=true \
--auth-type=tokens \
--auth-conf token=$BACKEND_OWNER_TOKEN
kumactl config control-planes switch --name cp-admin # switch back to admin

Change default Kong Mesh RBAC to restrict access to resources by default:

echo "type: AccessRoleBinding
name: default
subjects:
- type: Group
  name: mesh-system:admin
roles:
- admin" | kumactl apply -f -

Create Kong Mesh RBAC to restrict backend-owner to only modify TrafficPermission for backend:

echo '
type: AccessRole
name: backend-owner
rules:
- types: ["TrafficPermission"]
  mesh: default
  access: ["CREATE", "UPDATE", "DELETE"]
  when:
  - destinations:
      match:
        kuma.io/service: backend
' | kumactl apply -f -
echo '
type: AccessRoleBinding
name: backend-owners
subjects:
- type: User
  name: backend-owner
roles:
- backend-owner' | kumactl apply -f -

Change the user and test RBAC:

kumactl config control-planes switch --name cp-backend-owner
echo "
type: TrafficPermission
mesh: default
name: web-to-backend
sources:
- match:
    kuma.io/service: web
destinations:
- match:
    kuma.io/service: backend
" | kumactl apply -f -
# this operation should succeed

echo "
type: TrafficPermission
mesh: default
name: web-to-backend
sources:
- match:
    kuma.io/service: web
destinations:
- match:
    kuma.io/service: other
" | kumactl apply -f -
Error: Access Denied (user "backend-owner/mesh-system:authenticated" cannot access the resource)

Kubernetes

Universal

Create a backend-owner Kubernetes user and configure kubectl:

mkdir -p /tmp/k8s-certs
cd /tmp/k8s-certs
openssl genrsa -out backend-owner.key 2048 # generate client key
openssl req -new -key backend-owner.key -subj "/CN=backend-owner" -out backend-owner.csr # generate client certificate request
CSR=$(cat backend-owner.csr | base64 | tr -d "\n") && echo "apiVersion: certificates.k8s.io/v1
kind: CertificateSigningRequest
metadata:
  name: backend-owner
spec:
  request: $CSR
  signerName: kubernetes.io/kube-apiserver-client
  usages:
  - client auth" | kubectl apply -f -
kubectl certificate approve backend-owner
kubectl get csr backend-owner -o jsonpath='{.status.certificate}'| base64 -d > backend-owner.crt
kubectl config set-credentials backend-owner \
--client-key=/tmp/k8s-certs/backend-owner.key \
--client-certificate=/tmp/k8s-certs/backend-owner.crt \
--embed-certs=true
kubectl config set-context backend-owner --cluster=YOUR_CLUSTER_NAME --user=backend-owner

Create Kubernetes RBAC to allow backend-owner to manage all TrafficPermission:

echo "
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: kuma-policy-management
rules:
- apiGroups:
  - kuma.io
  resources:
  - meshtrafficpermissions
  verbs:
  - get
  - list
  - watch
  - create
  - update
  - patch
  - delete
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kuma-policy-management-backend-owner
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kuma-policy-management
subjects:
- kind: User
  name: backend-owner
  apiGroup: rbac.authorization.k8s.io
" | kubectl apply -f -

Change default Kong Mesh RBAC to restrict access to resources by default:

echo "
apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: default
spec:
  subjects:
  - type: Group
    name: mesh-system:admin
  - type: Group
    name: system:masters
  - type: Group
    name: system:serviceaccounts:kube-system
  roles:
  - admin
" | kubectl apply -f -

Create an AccessRole to grant permissions to user backend-owner to modify TrafficPermission only for the backend service:

echo '
---
apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: backend-owner
spec:
  rules:
  - types: ["MeshTrafficPermission"]
    mesh: default
    access: ["CREATE", "UPDATE", "DELETE"]
    when:
    - targetRef:
        kind: MeshService
        name: backend
---
apiVersion: kuma.io/v1alpha1
kind: AccessRoleBinding
metadata:
  name: backend-owners
spec:
  subjects:
  - type: User
    name: backend-owner
  roles:
  - backend-owner
' | kubectl apply -f -

Change the service to test user access:

kubectl config use-context backend-owner
echo "
apiVersion: kuma.io/v1alpha1
kind: MeshTrafficPermission
metadata:
  name: web-to-backend
  namespace: kong-mesh-system
  labels:
    kuma.io/mesh: default
spec:
  targetRef:
    kind: MeshService
    name: backend
  from:
    - targetRef:
        kind: MeshService
        name: web
      default:
        action: ALLOW
" | kubectl apply -f -
# operation should succeed, access to backend service access is granted

echo "
apiVersion: kuma.io/v1alpha1
kind: MeshTrafficPermission
metadata:
  name: web-to-backend
  namespace: kong-mesh-system
  labels:
    kuma.io/mesh: default
spec:
  targetRef:
    kind: MeshService
    name: not-backend # access to this service is not granted
  from:
    - targetRef:
        kind: MeshService
        name: web
      default:
        action: ALLOW
" | kubectl apply -f -
# operation should not succeed

Note: By default, all requests that originate from localhost are authenticated as the admin user in the mesh-system:admin group. For this example to work, you must either run the control plane with KUMA_API_SERVER_AUTHN_LOCALHOST_IS_ADMIN set to false or access the control plane using a method other than localhost.

Extract admin token and configure kumactl with admin:

export ADMIN_TOKEN=$(curl http://localhost:5681/global-secrets/admin-user-token | jq -r .data | base64 -d)
kumactl config control-planes add \
--name=cp-admin \
--address=https://localhost:5682 \
--skip-verify=true \
--auth-type=tokens \
--auth-conf token=$ADMIN_TOKEN

Configure backend-owner:

export BACKEND_OWNER_TOKEN=$(kumactl generate user-token --valid-for=24h --name backend-owner)
kumactl config control-planes add \
--name=cp-backend-owner \
--address=https://localhost:5682 \
--skip-verify=true \
--auth-type=tokens \
--auth-conf token=$BACKEND_OWNER_TOKEN
kumactl config control-planes switch --name cp-admin # switch back to admin

Change default Kong Mesh RBAC to restrict access to resources by default:

echo "type: AccessRoleBinding
name: default
subjects:
- type: Group
  name: mesh-system:admin
roles:
- admin" | kumactl apply -f -

Create Kong Mesh RBAC to only allow the backend-owner to modify TrafficPermission for backend:

echo '
type: AccessRole
name: backend-owner
rules:
- types: ["MeshTrafficPermission"]
  mesh: default
  access: ["CREATE", "UPDATE", "DELETE"]
  when:
  - targetRef:
      kind: MeshService
      name: backend
' | kumactl apply -f -
echo '
type: AccessRoleBinding
name: backend-owners
subjects:
- type: User
  name: backend-owner
roles:
- backend-owner' | kumactl apply -f -

Change the user and test RBAC:

kumactl config control-planes switch --name cp-backend-owner
echo "
type: MeshTrafficPermission
mesh: default
name: web-to-backend
spec:
  targetRef:
    kind: MeshService
    name: backend
  from:
    - targetRef:
        kind: MeshService
        name: web
      default:
        action: ALLOW
" | kumactl apply -f -
# this operation should succeed

echo "
type: MeshTrafficPermission
mesh: default
name: web-to-backend
spec:
  targetRef:
    kind: MeshService
    name: not-backend
  from:
    - targetRef:
        kind: MeshService
        name: web
      default:
        action: ALLOW
" | kumactl apply -f -
Error: Access Denied (user "backend-owner/mesh-system:authenticated" cannot access the resource)

Multi-zone

In a multi-zone setup, AccessRole and AccessRoleBinding are not synchronized between the global control plane and the zone control plane.

Wildcard tag value matching

Note: This feature is available starting in Kong Mesh 1.9.1

You can perform partial tag value matching using * wildcards.

For example, the following role:

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: AccessRole
metadata:
  name: role-wildcard
spec:
  rules:
  - types: ["TrafficRoute"]
    mesh: default
    access: ["CREATE", "UPDATE", "DELETE"]
    when:
    - sources:
        match:
          k8s.kuma.io/namespace: orders
      destinations:
        match:
          kuma.io/service: '*_orders_*'

type: AccessRole
name: role-wildcard
rules:
- types: ["TrafficRoute"]
  mesh: default
  access: ["CREATE", "UPDATE", "DELETE"]
  when:
  - sources:
      match:
        k8s.kuma.io/namespace: orders
    destinations:
      match:
        kuma.io/service: '*_orders_*'

would allow a subject to create the following resource:

Kubernetes

Universal

apiVersion: kuma.io/v1alpha1
kind: TrafficRoute
metadata:
  name: tr-orders
spec:
  sources:
    - match:
        k8s.kuma.io/namespace: 'orders'
  destinations:
    - match:
        kuma.io/service: web_orders_svc_1000
    - match:
        kuma.io/service: backend_orders_svc_1000
  conf:
    destination:
      kuma.io/service: '*'

type: TrafficRoute
mesh: default
name: tr-orders
sources:
  - match:
      k8s.kuma.io/namespace: 'orders'
destinations:
  - match:
      kuma.io/service: web_orders_svc_1000
  - match:
      kuma.io/service: backend_orders_svc_1000
conf:
  destination:
    kuma.io/service: '*'