How to deal with a namespace different from the globally set one? - kubernetes

Question

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: ns1
resources:
- r1a.yaml
- r1b.yaml
- r1c.yaml
- r1d.yaml
- r1e.yaml
- r2.yaml # needs to be placed in namespace ns2
Let's assume above situation. The problem is objects specified in r2.yaml would be place in ns1 even if ns2 is explicitely referenced in metadata.namespace.
How do I have to deal with this? Or how can I solve this (as I assume there a multiple options)?

Answer 1

I've looked into this and I came up with one idea.
├── base
│ ├── [nginx.yaml] Deployment nginx ns: default
| ├── [nginx2.yaml] Deployment nginx ns: default
| ├── [nginx3.yaml] Deployment nginx ns: default
| ├── [nginx4.yaml] Deployment nginx ns: default
| ├── [nginx5.yaml] Deployment nginx ns: nginx
│ └── [kustomization.yaml] Kustomization
└── prod
├── [kustomization.yaml] Kustomization
└── [patch.yaml] patching namespace
You need to have 2 directories, in this setup are: base and prod. In base directory you should use your base YAMLs and kustomization.yaml file. In my scenario I have 6 YAMLs: nginx/1/2/3/4.yaml based on Kubernetes Documentation, and nginx5.yaml which looks the same but with additional spec.namespace: nginx.
In base directory:
$ cat kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- nginx1.yaml
- nginx2.yaml
- nginx3.yaml
- nginx4.yaml
- nginx5.yaml
And 5 YAMLs with nginx.
In Prod directory:
You should have 2 files. kustomization.yaml and patch.yaml.
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: ns1
bases:
- ../base
patchesJson6902:
- target:
group: apps
version: v1
kind: Deployment
name: nginx-deployment-5
path: patch.yaml
$ cat patch.yaml
- op: replace
path: /metadata/namespace
value: nginx
When you will use kustomize build . in prod directory, all nginx-deployment/-2/-3/-4 will be in the namespace: ns1 and nginx-deployment-5 will be in namespace: nginx.
~/prod (project)$ kustomize build .
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-5
namespace: nginx
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- image: nginx:1.14.2
name: nginx
ports:
- containerPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
namespace: ns1
spec:
replicas: 2
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- image: nginx:1.14.2
name: nginx
ports:
- containerPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-2
namespace: ns1
spec:
Useful links:
Kustomize Builtin Plugins
Customizong
Kustomization Patches