diff --git a/docs/platform-engineers/workflow/workflow.md b/docs/platform-engineers/workflow/workflow.md new file mode 100644 index 00000000..c832af13 --- /dev/null +++ b/docs/platform-engineers/workflow/workflow.md @@ -0,0 +1,148 @@ +--- +title: Workflow +--- + +## Overview + +`Workflow` allows you to customize steps in `Application`, glue together additional delivery processes and specify arbitrary delivery environments. In short, `Workflow` provides customized control flow and flexibility based on the original delivery model of Kubernetes(Apply). For example, `Workflow` can be used to implement complex operations such as pause, manual approval, waiting status, data flow, multi-environment gray release, A/B testing, etc. + +`Workflow` is a further exploration and best practice based on OAM model in KubeVela, it obeys the modular concept and reusable characteristics of OAM. Each workflow module is a "super glue" that can combine your arbitrary tools and processes. In modern complex cloud native application delivery environment, you can completely describe all delivery processes through a declarative configuration, ensuring the stability and convenience of the delivery process. + +## Using workflow + +`Workflow` consists of steps, you can either use KubeVela's [built-in workflow steps], or write their own `WorkflowStepDefinition` to complete the operation. + +We can use `vela def` to define workflow steps by writing `Cue templates`. Let's write an `Application` that apply a Tomcat using Helm chart and automatically send message to Slack when the Tomcat is running. + +### Workflow Steps + +KubeVela provides several CUE actions for writing workflow steps. These actions are provided by the `vela/op` package. + +| Action | Description | Parameter | +| :---: | :--: | :-- | +| ApplyApplication | Apply all the resources in Application. | - | +| Read | Read resources in Kubernetes cluster. | value: the resource metadata to be get. And after successful execution, `value` will be updated with resource definition in cluster.
err: if an error occurs, the `err` will contain the error message. | +| ConditionalWait | The workflow step will be blocked until the condition is met. | continue: The workflow step will be blocked until the value becomes `true`. | +| ... | ... | ... | + +> For all the workflow actions, please refer to [Cue Actions](./cue-actions) + +We need two `WorkflowStepDefinitions` to complete the Application: + +1. Apply Tomcat and wait till it's status become running. We need to write a custom workflow step for it. +2. Send Slack notifications, we can use the built-in [webhook-notification] step for it. + +#### Step: Apply Tomcat + +First, use `vela def init` to generate a `WorkflowStepDefinition` template: + +```shell +vela def init my-helm -t workflow-step --desc "Apply helm charts and wait till it's running." -o my-helm.cue +``` + +The result is as follows: +```shell +$ cat my-helm.cue + +"my-helm": { + annotations: {} + attributes: {} + description: "Apply helm charts and wait till it's running." + labels: {} + type: "workflow-step" +} + +template: { +} +``` + +Import `vela/op` and complete the Cue code in `template`: + +``` +import ( + "vela/op" +) + +"my-helm": { + annotations: {} + attributes: {} + description: "Apply helm charts and wait till it's running." + labels: {} + type: "workflow-step" +} + +template: { + // Apply all the resources in Application + apply: op.#ApplyApplication & {} + + resource: op.#Read & { + value: { + kind: "Deployment" + apiVersion: "apps/v1" + metadata: { + name: "tomcat" + // we can use context to get any metadata in Application + namespace: context.namespace + } + } + } + + workload: resource.value + // wait till it's ready + wait: op.#ConditionalWait & { + continue: workload.status.readyReplicas == workload.status.replicas && workload.status.observedGeneration == workload.metadata.generation + } +} +``` + +Apply it to the cluster: + +```shell +$ vela def apply my-helm.cue + +WorkflowStepDefinition my-helm in namespace vela-system updated. +``` + +#### Step: Send Slack notifications + +Use the built-in step, [webhook-notification]. + +### Apply the Application + +```yaml +apiVersion: core.oam.dev/v1beta1 +kind: Application +metadata: + name: first-vela-workflow + namespace: default +spec: + components: + - name: tomcat + type: helm + properties: + repoType: helm + repoUrl: https://charts.bitnami.com/bitnami + chart: tomcat + version: "9.2.20" + workflow: + steps: + - name: tomcat + # specify the step type + type: my-helm + outputs: + - name: msg + # export the deployment status in my-helm + exportKey: resource.value.status.conditions[0].message + - name: send-message + type: webhook-notification + inputs: + - from: msg + # use the output value in the previous step and pass it into the properties slack.message.text + parameterKey: slack.message.text + properties: + slack: + # the address of your slack webhook, please refer to: https://api.slack.com/messaging/webhooks + url: slack url +``` + +Apply the Application to the cluster and you can see that all resources have been successfully applied and Slack has received the messages of the Deployment status. diff --git a/i18n/zh/docusaurus-plugin-content-docs/current/platform-engineers/workflow/workflow.md b/i18n/zh/docusaurus-plugin-content-docs/current/platform-engineers/workflow/workflow.md new file mode 100644 index 00000000..21619260 --- /dev/null +++ b/i18n/zh/docusaurus-plugin-content-docs/current/platform-engineers/workflow/workflow.md @@ -0,0 +1,148 @@ +--- +title: 工作流 +--- + +## 总览 + +KubeVela 的工作流机制允许你自定义应用部署计划中的步骤,粘合额外的交付流程,指定任意的交付环境。简而言之,工作流提供了定制化的控制逻辑,在原有 Kubernetes 模式交付资源(Apply)的基础上,提供了面向过程的灵活性。比如说,使用工作流实现暂停、人工验证、状态等待、数据流传递、多环境灰度、A/B 测试等复杂操作。 + +工作流是 KubeVela 实践过程中基于 OAM 模型的进一步探索和最佳实践,充分遵守 OAM 的模块化理念和可复用特性。每一个工作流模块都是一个“超级粘合剂”,可以将你任意的工具和流程都组合起来。使得你在现代复杂云原生应用交付环境中,可以通过一份申明式的配置,完整的描述所有的交付流程,保证交付过程的稳定性和便利性。 + +## 使用工作流 + +工作流由步骤组成,你既可以使用 KubeVela 提供的 [内置工作流步骤] 来便利地完成操作,也可以自己来编写 `WorkflowStepDefinition` 来达到想要的效果。 + +我们可以使用 `vela def` 通过编写 `Cue template` 来定义工作流步骤。下面我们来完成这个场景:使用 Helm 部署一个 Tomcat,并在部署完成后自动向 Slack 发送消息通知。 + +### 编写工作流步骤 + +KubeVela 提供了一些 CUE 操作类型用于编写工作流步骤。这些操作均由 `vela/op` 包提供。 + +| 操作名 | 说明 | 参数 | +| :---: | :--: | :-- | +| ApplyApplication | 部署应用中的所有资源 | - | +| Read | 读取 Kubernetes 集群中的资源。 | value: 描述需要被读取资源的元数据,比如 kind、name 等,操作完成后,集群中资源的数据会被填充到 `value` 上。
err: 如果读取操作发生错误,这里会以字符串的方式指示错误信息。 | +| ConditionalWait | 会让 Workflow Step 处于等待状态,直到条件被满足。 | continue: 当该字段为 true 时,Workflow Step 才会恢复继续执行。 | +| ... | ... | ... | + +> 所有的操作类型可参考 [Cue Actions](./cue-actions) + +为了完成这个场景,我们需要两个 `WorkflowStepDefinition`: + +1. 部署 Tomcat,并且等待 Deployment 的状态变为 running,这一步需要自定义工作流步骤来实现。 +2. 发送 Slack 通知,这一步可以使用 KubeVela 内置的 [webhook-notification] 步骤来实现。 + +#### 部署 Tomcat 步骤 + +首先,通过 `vela def init` 来生成一个 `WorkflowStepDefinition` 模板: + +```shell +vela def init my-helm -t workflow-step --desc "Apply helm charts and wait till it's running." -o my-helm.cue +``` + +得到如下结果: +```shell +$ cat my-helm.cue + +"my-helm": { + annotations: {} + attributes: {} + description: "Apply helm charts and wait till it's running." + labels: {} + type: "workflow-step" +} + +template: { +} +``` + +引用 `vela/op` 包,并将 Cue 代码补充到 `template` 中: + +``` +import ( + "vela/op" +) + +"my-helm": { + annotations: {} + attributes: {} + description: "Apply helm charts and wait till it's running." + labels: {} + type: "workflow-step" +} + +template: { + // 部署应用中的所有资源 + apply: op.#ApplyApplication & {} + + resource: op.#Read & { + value: { + kind: "Deployment" + apiVersion: "apps/v1" + metadata: { + name: "tomcat" + // 可以使用 context 来获取该 Application 的任意元信息 + namespace: context.namespace + } + } + } + + workload: resource.value + // 等待 helm 的 deployment 可用 + wait: op.#ConditionalWait & { + continue: workload.status.readyReplicas == workload.status.replicas && workload.status.observedGeneration == workload.metadata.generation + } +} +``` + +部署到集群中: + +```shell +$ vela def apply my-helm.cue + +WorkflowStepDefinition my-helm in namespace vela-system updated. +``` + +#### 发送 Slack 通知步骤 + +直接使用内置的 [webhook-notification] 步骤。 + +### 编写应用 + +```yaml +apiVersion: core.oam.dev/v1beta1 +kind: Application +metadata: + name: first-vela-workflow + namespace: default +spec: + components: + - name: tomcat + type: helm + properties: + repoType: helm + repoUrl: https://charts.bitnami.com/bitnami + chart: tomcat + version: "9.2.20" + workflow: + steps: + - name: tomcat + # 指定步骤类型 + type: my-helm + outputs: + - name: msg + # 将 my-helm 中读取到的 deployment status 作为信息导出 + exportKey: resource.value.status.conditions[0].message + - name: send-message + type: webhook-notification + inputs: + - from: msg + # 引用上一步中 outputs 中的值,并传入到 properties 的 slack.message.text 中作为输入 + parameterKey: slack.message.text + properties: + slack: + # 你的 slack webhook 地址,请参考:https://api.slack.com/messaging/webhooks + url: slack url +``` + +将该应用部署到集群中,可以看到所有的资源都已被成功部署,且 Slack 中收到了对应的通知,通知内容为该 Deployment 的状态信息。 \ No newline at end of file