I have a base and two overlays: dev and prod, and all objects(Deployments, StatefulSets, Services etc.) defined in base layer are inherited in the two overlays. However, for some technical reason, I’d like to duplicate a specific Service “foo” in overlay prod to “foo-a”, “foo-b”, “foo-c”, but keep it unchanged in overlay dev. Like the following:
.
├── base
│ ├── Service:foo
│ ├── Deployment:bar
│ ├── StatefulSet:baz
│ └── ...
└── overlays
├── dev
│ ├── Service:foo <-- base/Service:foo kept unchanged
│ ├── Deployment:bar
│ ├── StatefulSet:baz
│ └── ...
└── prod
├── Service:foo-a <-- duplicated from base/Service:foo
├── Service:foo-b <-- duplicated from base/Service:foo
├── Service:foo-c <-- duplicated from base/Service:foo
├── Deployment:bar
├── StatefulSet:baz
└── ...
Currently, the multibases solution is the closest solution, however, this solution duplicates all objects in a layer, but not a specific one.
I think I might use a script to achieve this, but I prefer the “kustomize” way. Any ideas? Thanks.
2
You can’t do what you want with your existing layout; Kustomize is only able to include directories, not individual files, and there’s no facility for “duplicating” a resource. If we move your Service manifest into a component and modify your overlays a bit, we can get closer.
I ended up with the following layout (I didn’t include your example statefuleset because it wasn’t relevant to the answer):
.
├── base
│ ├── deployment.yaml
│ └── kustomization.yaml
├── components
│ └── service
│ ├── kustomization.yaml
│ └── service.yaml
└── overlays
├── dev
│ └── kustomization.yaml
└── prod
├── kustomization.yaml
├── service-a
│ └── kustomization.yaml
├── service-b
│ └── kustomization.yaml
└── service-c
└── kustomization.yaml
base/kustomization.yaml looks like this:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- deployment.yaml
And deployment.yaml looks like:
apiVersion: apps/v1
kind: Deployment
metadata:
name: example
spec:
template:
spec:
containers:
- name: example
image: docker.io/traefik/whoami:latest
env:
- name: WHOAMI_PORT_NUMBER
value: "8080"
ports:
- containerPort: 8080
name: http
Note that here and elsewhere I’m relying on kustomize to fill in labels and selectors.
components/service/kustomization.yaml looks like this (note the apiVersion):
apiVersion: kustomize.config.k8s.io/v1alpha1
kind: Component
resources:
- service.yaml
And service.yaml looks like this:
apiVersion: v1
kind: Service
metadata:
name: example
spec:
ports:
- name: http
port: 8080
Then we create overlays/dev/kustomization.yaml like this:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
commonLabels:
app: example
environment: dev
resources:
- ../../base
components:
- ../../components/service/
Running kustomize build overlays/dev gets us:
apiVersion: v1
kind: Service
metadata:
labels:
app: example
environment: dev
name: example
spec:
ports:
- name: http
port: 8080
selector:
app: example
environment: dev
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: example
environment: dev
name: example
spec:
selector:
matchLabels:
app: example
environment: dev
template:
metadata:
labels:
app: example
environment: dev
spec:
containers:
- env:
- name: WHOAMI_PORT_NUMBER
value: "8080"
image: docker.io/traefik/whoami:latest
name: example
ports:
- containerPort: 8080
name: http
overlays/prod is a little more interesting. overlays/prod/kustomization.yaml looks like this:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
commonLabels:
app: example
environment: prod
resources:
- ../../base
- service-a
- service-b
- service-c
overlays/prod/service-a/kustomization.yaml looks like this:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
nameSuffix: -a
components:
- ../../../components/service/
service-b and service-c are similar; we just use a different nameSuffix. Running kustomize build overlays/prod results in a Deployment and three Services:
apiVersion: v1
kind: Service
metadata:
labels:
app: example
environment: prod
name: example-a
spec:
ports:
- name: http
port: 8080
selector:
app: example
environment: prod
---
apiVersion: v1
kind: Service
metadata:
labels:
app: example
environment: prod
name: example-b
spec:
ports:
- name: http
port: 8080
selector:
app: example
environment: prod
---
apiVersion: v1
kind: Service
metadata:
labels:
app: example
environment: prod
name: example-c
spec:
ports:
- name: http
port: 8080
selector:
app: example
environment: prod
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: example
environment: prod
name: example
spec:
selector:
matchLabels:
app: example
environment: prod
template:
metadata:
labels:
app: example
environment: prod
spec:
containers:
- env:
- name: WHOAMI_PORT_NUMBER
value: "8080"
image: docker.io/traefik/whoami:latest
name: example
ports:
- containerPort: 8080
name: http
I think that’s roughly what you were looking for.
1