nsinjector

nsinjector

nsinjector is a Kubernetes controller that automatically deploys resources into a namespace when it is created.

Here's a blog post I wrote about it: Deploy Kubernetes resources automatically with nsinjector .

How to use it

You can find a chart with an example values.yaml file in deploy/helm. With helm3, you can deploy it with:

helm install nsinjector-controller ./deploy/helm

Alternatively, you can manually deploy manifest stored in deploy/k8s:

# Deploy CRD first. If your cluster is >= v1.16, you can use namespaceresourcesinjector-crd-1.16.yaml instead
kubectl apply -f deploy/k8s/namespaceresourcesinjector-crd.yaml
# Deploy the controller
kubectl apply -f deploy/k8s/nsinjector-controller.yaml
# Then deploy an injector custom resource
# This is the file that you'll want to customize to your needs
kubectl apply -f deploy/k8s/namespaceresourcesinjector.yaml

Example

When a namespace starting with dev- is created, the following resource will automatically inject a role and rolebinding in it:

kind: NamespaceResourcesInjector
apiVersion: blakelead.com/v1alpha1
metadata:
  name: nri-test
spec:
  namespaces:
  - dev-.*
  excludedNamespaces:
  - dev-excluded-.* 
  resources:
  - |
    apiVersion: rbac.authorization.k8s.io/v1
    kind: Role
    metadata:
      name: dev-role
    rules:
      - apiGroups: [""]
        resources: ["pods","pods/portforward", "services", "deployments", "ingresses"]
        verbs: ["list", "get"]
      - apiGroups: [""]
        resources: ["pods/portforward"]
        verbs: ["create"]
      - apiGroups: [""]
        resources: ["namespaces"]
        verbs: ["list", "get"]
  - |
    apiVersion: rbac.authorization.k8s.io/v1
    kind: RoleBinding
    metadata:
      name: dev-rolebinding
    subjects:
    - kind: User
      name: dev
    roleRef:
      kind: Role
      name: dev-role
      apiGroup: rbac.authorization.k8s.io

• namespaces: a list of namespace names or regex
• excludedNamespaces: a list of namespace names or regex to be excluded
• resources: a list of any Kubernetes resources

Contributing

Although this project is currently used in production, it is relatively young and has not been extensively tested. Suggestions and contributions are therefore very welcome.