use Kustomize to create additional namespaces with a suffix - kubernetes

Question

Just currently battling an issue with kustomize and not having much look.
I have my config setup and are using kustomize (v4.5.7) to have separate base, variants and environment configuration. I’m trying to use the setup to deploy a copy of my dev environment onto the same cluster using different namespaces and a suffix.
The idea is that everything would be deployed using a suffix for the name (and got this working but it only does the names and not the namespaces) and drop them into separate namespaces with a suffix.
I’m currently defining all the namspaces with the following config:
apiVersion: v1
kind: Namespace
metadata:
name: mynamespace
Now i want to be able to deploy copies of the NS named mynamespace-mysuffix
I’ve managed to implemented a suffix for the names of the object alongside a PrefixSuffixTransformer to update the namespaces in the objects created to mynamespace-mysuffix
This unfortunately doesn’t update the namespace configuration and leaves things in tact. In short it tries to deploy the objects into namespaces that do not exist.
This is the working PrefixSuffixTransformer amending the namespace set in the various objects:
apiVersion: builtin
kind: PrefixSuffixTransformer
metadata:
name: customSuffixer
suffix: "-mysuffix"
fieldSpecs:
- path: metadata/name
- path: metadata/namespace
trying to target the namespace objects unsuccessfully with the following additional PrefixSuffixTransformer
apiVersion: builtin
kind: PrefixSuffixTransformer
metadata:
name: nsSuffixer
suffix: "-mysuffix"
fieldSpecs:
- kind: Namespace
path: metadata/name
Was hoping on this last part working but no success. Anyone any suggestions as to how I can get the additional namespaces created with a suffix?

Answer 1

If I understand your question correctly, the solution is just to add a namespace: declaration to the kustomization.yaml file in your variants.
For example, if I have a base directory that contains:
namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
name: example
spec: {}
service.yaml
apiVersion: v1
kind: Service
metadata:
name: example
spec:
ports:
- name: http
port: 80
targetPort: http
kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: example
resources:
- namespace.yaml
- service.yaml
And I create a variant in overlays/example, with this kustomization.yaml:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: example-mysuffix
resources:
- ../../base
nameSuffix: -mysuffix
Then running kustomize build overlays/example results in:
apiVersion: v1
kind: Namespace
metadata:
name: example
spec: {}
---
apiVersion: v1
kind: Service
metadata:
name: example-mysuffix
namespace: example
spec:
ports:
- name: http
port: 80
targetPort: http
As you have described in your question, the Namespace resource wasn't renamed by the nameSuffix configuration. But if I simply add a namespace: declaration to the kustomization.yaml, like this:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: example-mysuffix
resources:
- ../../base
nameSuffix: -mysuffix
Then I get the desired output:
apiVersion: v1
kind: Namespace
metadata:
name: example-mysuffix
spec: {}
---
apiVersion: v1
kind: Service
metadata:
name: example-mysuffix
namespace: example-mysuffix
spec:
ports:
- name: http
port: 80
targetPort: http