kubectl/docs/book/pages/app_management/namespaces_and_names.md

{% panel style="success", title="Providing Feedback" %} Provide feedback at the survey {% endpanel %}

{% panel style="info", title="TL;DR" %}

• Set the Namespace for all Resources within a Project with namespace
• Prefix the Names of all Resources within a Project with namePrefix
• Suffix the Names of all Resources within a Project with nameSuffix {% endpanel %}

Setting Namespaces and Names

Motivation

It may be useful to enforce consistency across the namespace and names of all Resources within a Project.

• Ensure all Resources are in the correct Namespace
• Ensure all Resources share a common naming convention
• Copy or Fork an existing Project and change the Namespace / Names

See Bases and Variations for more details on Copying Projects.

{% panel style="info", title="Reference" %}

• namespace
• namePrefix
• nameSuffix {% endpanel %}

Setting the Namespace for all Resources

Reference:

The Namespace for all namespaced Resources declared in the Resource Config may be set with namespace. This sets the namespace for both generated Resources (e.g. ConfigMaps and Secrets) and non-generated Resources.

{% method %} Example: Set the namespace specified in the kustomization.yaml on the namespaced Resources.

{% sample lang="yaml" %} Input: The kustomization.yaml and deployment.yaml files

# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: my-namespace
resources:
- deployment.yaml

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

Applied: The Resource that is Applied to the cluster

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: nginx-deployment
  # The namespace has been added
  namespace: my-namespace
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx

{% endmethod %}

{% panel style="info", title="Overriding Namespaces" %} Setting the namespace will override the namespace on Resources if it is already set. {% endpanel %}

Setting a Name prefix or suffix for all Resources

A name prefix or suffix can be set for all resources using namePrefix or nameSuffix.

{% method %} Example: Prefix the names of all Resources.

{% sample lang="yaml" %} Input: The kustomization.yaml and deployment.yaml files

# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namePrefix: foo-
resources:
- deployment.yaml

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

Applied: The Resource that is Applied to the cluster

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  # The name has been prefixed with "foo-"
  name: foo-nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx

{% endmethod %}

{% panel style="info", title="Propagation of the Name to Object References" %} Resources such as Deployments and StatefulSets may reference other Resources such as ConfigMaps and Secrets in the Pod Spec.

This sets a name prefix or suffix for both generated Resources (e.g. ConfigMaps and Secrets) and non-generated Resources.

The namePrefix or nameSuffix that is applied is propagated to references to updated resources - e.g. references to Secrets and ConfigMaps are updated with the namePrefix and nameSuffix. {% endpanel %}

{% method %} Example: Prefix the names of all Resources.

This will update the ConfigMap reference in the Deployment to have the foo prefix.

{% sample lang="yaml" %} Input: The kustomization.yaml and deployment.yaml files

# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namePrefix: foo-
configMapGenerator:
- name: props
  literals:	
  - BAR=baz
resources:
- deployment.yaml

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        env:
        - name: BAR
          valueFrom:
            configMapKeyRef:
              name: props
              key: BAR

Applied: The Resource that is Applied to the cluster

apiVersion: v1
data:
 BAR: baz
kind: ConfigMap
metadata:
 creationTimestamp: null
 name: foo-props-44kfh86dgg
---
apiVersion: apps/v1
kind: Deployment
metadata:
 labels:
   app: nginx
 name: foo-nginx-deployment
spec:
 selector:
   matchLabels:
     app: nginx
 template:
   metadata:
     labels:
       app: nginx
   spec:
     containers:
     - env:
       - name: BAR
         valueFrom:
           configMapKeyRef:
             key: BAR
             name: foo-props-44kfh86dgg
       image: nginx
       name: nginx

{% endmethod %}

{% panel style="info", title="References" %} Apply will propagate the namePrefix to any place Resources within the project are referenced by other Resources including:

• Service references from StatefulSets
• ConfigMap references from PodSpecs
• Secret references from PodSpecs {% endpanel %}