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编辑管理模块定义

在 KubeVela CLI (>= v1.1.0) 工具中,vela def 命令组为开发者提供了一系列便捷的 X-Definition 编写工具,使得 Definition 的编写将全部在 CUE 文件中进行,避免将 Template CUE 与 Kubernetes 的 YAML 格式进行混合,方便进行格式化与校验。

init#

vela def init 是一个用来帮助用户初始化新的 Definition 的脚手架命令。用户可以通过 vela def init my-trait -t trait --desc "My trait description." 来创建一个新的空白 TraitDefinition ,如下

"my-trait": {
annotations: {}
attributes: {
appliesToWorkloads: []
conflictsWith: []
definitionRef: ""
podDisruptive: false
workloadRefPath: ""
}
description: "My trait description."
labels: {}
type: "trait"
}
template: patch: {}

或者是采用 vela def init my-comp --interactive 来交互式地创建新的 Definition 。

$ vela def init my-comp --interactive
Please choose one definition type from the following values: component, trait, policy, workload, scope, workflow-step
> Definition type: component
> Definition description: My component definition.
Please enter the location the template YAML file to build definition. Leave it empty to generate default template.
> Definition template filename:
Please enter the output location of the generated definition. Leave it empty to print definition to stdout.
> Definition output filename: my-component.cue
Definition written to my-component.cue

除此之外,如果用户创建 ComponentDefinition 的目的是一个 Deployment(或者是其他的 Kubernetes Object ),而这个 Deployment 已经有了 YAML 格式的模版,用户还可以通过 --template-yaml 参数来完成从 YAML 到 CUE 的自动转换。例如如下的 my-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
name: hello-world
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: hello-world
template:
metadata:
labels:
app.kubernetes.io/name: hello-world
spec:
containers:
- name: hello-world
image: somefive/hello-world
ports:
- name: http
containerPort: 80
protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
name: hello-world-service
spec:
selector:
app: hello-world
ports:
- name: http
protocol: TCP
port: 80
targetPort: 8080
type: LoadBalancer

运行 vela def init my-comp -t component --desc "My component." --template-yaml ./my-deployment.yaml 可以得到 CUE 格式的 ComponentDefinition

"my-comp": {
annotations: {}
attributes: workload: definition: {
apiVersion: "<change me> apps/v1"
kind: "<change me> Deployment"
}
description: "My component."
labels: {}
type: "component"
}
template: {
output: {
metadata: name: "hello-world"
spec: {
replicas: 1
selector: matchLabels: "app.kubernetes.io/name": "hello-world"
template: {
metadata: labels: "app.kubernetes.io/name": "hello-world"
spec: containers: [{
name: "hello-world"
image: "somefive/hello-world"
ports: [{
name: "http"
containerPort: 80
protocol: "TCP"
}]
}]
}
}
apiVersion: "apps/v1"
kind: "Deployment"
}
outputs: "hello-world-service": {
metadata: name: "hello-world-service"
spec: {
ports: [{
name: "http"
protocol: "TCP"
port: 80
targetPort: 8080
}]
selector: app: "hello-world"
type: "LoadBalancer"
}
apiVersion: "v1"
kind: "Service"
}
parameter: {}
}

接下来,用户就可以在该文件的基础上进一步做进一步的修改了。比如将属性中对于 workload.definition 中的 \<change me> 去掉。

vet#

在初始化 Definition 文件之后,可以运行 vela def vet my-comp.cue 来校验 Definition 是否在语法上有错误。比如如果少写了一个括号,该命令能够帮助用户识别出来。

$ vela def vet my-comp.cue
Validation succeed.

render / apply#

确认 Definition 撰写无误后,开发者可以运行 vela def apply my-comp.cue --namespace my-namespace 来将该 Definition 应用在 Kubernetes 的 my-namespace 命名空间中。如果想了解一下 CUE 格式的 Definition 文件会被渲染成什么样的 Kubernetes YAML 文件,可以使用 vela def apply my-comp.cue --dry-run 或者 vela def render my-comp.cue -o my-comp.yaml 来预先渲染一下 YAML 文件进行确认。

apiVersion: core.oam.dev/v1beta1
kind: ComponentDefinition
metadata:
annotations:
definition.oam.dev/description: My component.
labels: {}
name: my-comp
namespace: vela-system
spec:
schematic:
cue:
template: |
output: {
metadata: name: "hello-world"
spec: {
replicas: 1
selector: matchLabels: "app.kubernetes.io/name": "hello-world"
template: {
metadata: labels: "app.kubernetes.io/name": "hello-world"
spec: containers: [{
name: "hello-world"
image: "somefive/hello-world"
ports: [{
name: "http"
containerPort: 80
protocol: "TCP"
}]
}]
}
}
apiVersion: "apps/v11"
kind: "Deployment"
}
outputs: "hello-world-service": {
metadata: name: "hello-world-service"
spec: {
ports: [{
name: "http"
protocol: "TCP"
port: 80
targetPort: 8080
}]
selector: app: "hello-world"
type: "LoadBalancer"
}
apiVersion: "v1"
kind: "Service"
}
parameter: {}
workload:
definition:
apiVersion: apps/v1
kind: Deployment
$ vela def apply my-comp.cue -n my-namespace
ComponentDefinition my-comp created in namespace my-namespace.

get / list / edit / del#

在 apply 命令后,开发者可以采用原生的 kubectl 来对结果进行确认,但是正如我们上文提到的,YAML 格式的结果会相对复杂。使用 vela def get 命令可以自动将其转换成 CUE 格式,方便用户查看。

$ vela def get my-comp -t component

或者用户可以通过 vela def list 命令来查看当前系统中安装的所有 Definition(可以指定命名空间及类型)。

$ vela def list -n my-namespace -t component
NAME TYPE NAMESPACE DESCRIPTION
my-comp ComponentDefinition my-namespace My component.

同样的,在使用 vela def edit 命令来编辑 Definition 时,用户也只需要对转换过的 CUE 格式 Definition 进行修改,该命令会自动完成格式转换。用户也可以通过设定环境变量 EDITOR 来使用自己想要使用的编辑器。

$ EDITOR=vim vela def edit my-comp

类似的,用户可以运行 vela def del 来删除相应的 Definition。

$ vela def del my-comp -n my-namespace
Are you sure to delete the following definition in namespace my-namespace?
ComponentDefinition my-comp: My component.
[yes|no] > yes
ComponentDefinition my-comp in namespace my-namespace deleted.

下一步#

Last updated on by Jianbo Sun