kubevela.github.io/docs/platform-engineers/cloneset.md

93 lines
2.7 KiB
Markdown

---
title: Extend CRD Operator as Component Type
---
Let's use [OpenKruise](https://github.com/openkruise/kruise) as example of extend CRD as KubeVela Component.
**The mechanism works for all CRD Operators**.
### Step 1: Install the CRD controller
You need to [install the CRD controller](https://github.com/openkruise/kruise#quick-start) into your K8s system.
### Step 2: Create Component Definition
To register Cloneset(one of the OpenKruise workloads) as a new workload type in KubeVela, the only thing needed is to create an `ComponentDefinition` object for it.
A full example can be found in this [cloneset.yaml](https://github.com/oam-dev/catalog/blob/master/registry/cloneset.yaml).
Several highlights are list below.
#### 1. Describe The Workload Type
```yaml
...
annotations:
definition.oam.dev/description: "OpenKruise cloneset"
...
```
A one line description of this component type. It will be shown in helper commands such as `$ vela components`.
#### 2. Register it's underlying CRD
```yaml
...
workload:
definition:
apiVersion: apps.kruise.io/v1alpha1
kind: CloneSet
...
```
This is how you register OpenKruise Cloneset's API resource (`fapps.kruise.io/v1alpha1.CloneSet`) as the workload type.
KubeVela uses Kubernetes API resource discovery mechanism to manage all registered capabilities.
#### 4. Define Template
```yaml
...
schematic:
cue:
template: |
output: {
apiVersion: "apps.kruise.io/v1alpha1"
kind: "CloneSet"
metadata: labels: {
"app.oam.dev/component": context.name
}
spec: {
replicas: parameter.replicas
selector: matchLabels: {
"app.oam.dev/component": context.name
}
template: {
metadata: labels: {
"app.oam.dev/component": context.name
}
spec: {
containers: [{
name: context.name
image: parameter.image
}]
}
}
}
}
parameter: {
// +usage=Which image would you like to use for your service
// +short=i
image: string
// +usage=Number of pods in the cloneset
replicas: *5 | int
}
```
### Step 3: Register New Component Type to KubeVela
As long as the definition file is ready, you just need to apply it to Kubernetes.
```bash
$ kubectl apply -f https://raw.githubusercontent.com/oam-dev/catalog/master/registry/cloneset.yaml
```
And the new component type will immediately become available for developers to use in KubeVela.