kubectl dash k
━━━━━━━━━━━━━━

Kubernetes ships with a feature called kustomize that allows you to customize your manifests in a declarative way. It's a bit like helm, but easier to use. I...

Date: July 5, 2024

Kubernetes ships with a feature called kustomize that allows you to customize your manifests in a declarative way. It’s a bit like helm, but easier to use. I found this useful.

kustomization.yaml
──────────────────

In order to use kustomize you need to have a kustomization.yaml, kustomization.yml, or Kustomization file in the directory you are applying.

```
kubectl apply -k .
error: unable to find one of 'kustomization.yaml', 'kustomization.yml' or 'Kustomization' in directory '/tank/git/kustomize-playground'
```

The kustomization.yaml file cannot be empty.

```
❯ kubectl apply -k pod
error: kustomization.yaml is empty
```

lets make an mvp
────────────────

```
mkdir pod
touch pod/pod.yaml
touch pod/kustomization.yaml
```

```
# pod.yaml
```

```
# kustomization.yaml
```

Overlays
────────

Overlays must point to yaml or a directory with a kustomization.yaml file, and cannot reside inside the same directory causing a circular reference.

--------

Layout
──────

```
k8s
├── base
│   ├── deployment.yaml
│   └── kustomization.yaml
├── overlays
│   ├── local
│   │   └── kustomization.yaml
│   ├── dev
│   │   └── kustomization.yaml
│   └── prod
│       ├── special-prod.yaml
│       └── kustomization.yaml
```

base
────

Place all of the common k8s manifests here in the base directory along with kustomization.yaml. You can split them up into separate files or just one file, I’m keeping it to one for simiplicity.

base - kustomization.yaml
─────────────────────────

In the base kustomization.yaml file add all of the manifests that you want to use as a resource.

```
resources:
  - deployment.yaml
```

overlays
────────

Now for each separate environment that you want to have create a directory in overlays with a kustomization.yaml file, and any special manifests that only apply to a particular environment.

overlays - kustomization.yaml
─────────────────────────────

### resoures

```
resources:
  - ../../base
# any other specific resources, maybe special ones for prod here
  - sealed-dotenv.yaml
```

### images

```
images:
  - name: my-image
    newName: docker.io/myrepo/myimage
    newTag: 1.0.0
```