Knative实战：Broker和Trigger的使用 2021-06-05 Serverless 暂无评论 2812 次阅读 > 本文基于Knative v0.23版本 ## 开始使用Knative Eventing ### **创建一个Knative Eventing namespace** ```bash kubectl create namespace event-example ``` ### **添加一个broker** broker路由事件到不同的事件接收器或消费者。 - 用以下命令添加一个叫做`default`的broker： ```bash kubectl create -f - <<EOF apiVersion: eventing.knative.dev/v1 kind: broker metadata: name: default namespace: event-example EOF ``` - 确认broker正确运行： ```bash kubectl -n event-example get broker default ``` 确保`Ready`状态为`True`： ```bash NAME URL AGE READY REASON default http://broker-ingress.knative-eventing.svc.cluster.local/event-example/default 45s True ``` ### **创建事件消费者** 在这里我们创建两个事件消费者，`hello-display`和`goodbye-display`，来演示怎么配置事件生产者来针对特定的消费者。 - 用以下命令部署`hello-display`消费者到集群中： ```bash kubectl -n event-example apply -f - << EOF apiVersion: apps/v1 kind: Deployment metadata: name: hello-display spec: replicas: 1 selector: matchLabels: &labels app: hello-display template: metadata: labels: *labels spec: containers: - name: event-display image: gcr.io/knative-releases/knative.dev/eventing/cmd/event_display --- kind: Service apiVersion: v1 metadata: name: hello-display spec: selector: app: hello-display ports: - protocol: TCP port: 80 targetPort: 8080 EOF ``` - 用以下命令部署`goodbye-display`消费者到集群中： ```bash kubectl -n event-example apply -f - << EOF apiVersion: apps/v1 kind: Deployment metadata: name: goodbye-display spec: replicas: 1 selector: matchLabels: &labels app: goodbye-display template: metadata: labels: *labels spec: containers: - name: event-display # Source code: https://github.com/knative/eventing/tree/main/cmd/event_display image: gcr.io/knative-releases/knative.dev/eventing/cmd/event_display --- kind: Service apiVersion: v1 metadata: name: goodbye-display spec: selector: app: goodbye-display ports: - protocol: TCP port: 80 targetPort: 8080 EOF ``` - 用以下命令确认消费者正常工作： ```bash kubectl -n event-example get deployments hello-display goodbye-display ``` 上述命令能列出我们部署的`hello-display`和`goodbye-display`消费者： ```bash NAME READY UP-TO-DATE AVAILABLE AGE hello-display 1/1 1 1 2m1s goodbye-display 1/1 1 1 47s ``` `READY`列副本数量要与`AVAILABLE`列匹配。 ### **创建triggers** Triggers定义了每个事件消费者接受到的事件。Brokers使用triggers将事件发送给正确的消费者。每个trigger能够指定一个过滤器，该过滤器能够基于Cloud Event context attribute选择相关的事件。 - 创建一个trigger： ```bash kubectl -n event-example apply -f - << EOF apiVersion: eventing.knative.dev/v1 kind: Trigger metadata: name: hello-display spec: broker: default filter: attributes: type: greeting subscriber: ref: apiVersion: v1 kind: Service name: hello-display EOF ``` 该命令创建了一个的trigger来发送所有`type`为`greeting`的事件到一个名为`hello-display`的事件消费者。 - 创建第二个消费者： ```bash kubectl -n event-example apply -f - << EOF apiVersion: eventing.knative.dev/v1 kind: Trigger metadata: name: goodbye-display spec: broker: default filter: attributes: source: sendoff subscriber: ref: apiVersion: v1 kind: Service name: goodbye-display EOF ``` 该命令创建了一个trigger用来发送所有`source`为`sendoff`的事件到名为`goodbye-display`的事件消费者。 - 确认trigger正常工作： ```bash kubectl -n event-example get triggers ``` 该命令返回刚刚创建的两个triggers： ```bash NAME BROKER SUBSCRIBER_URI AGE READY REASON goodbye-display default http://goodbye-display.event-example.svc.cluster.local/ 44s True hello-display default http://hello-display.event-example.svc.cluster.local/ 4m47s True ``` 如果triggers配置正确，则会Ready并且指向正确的broker和SUBSCRIBER_URI。 ### **创建一个Pod作为事件生产者** 我们使用`curl`命令手动将单个事件作为HTTP请求发送给broker，并演示这些事件怎么被事件消费者正确的接收。 只能从安装了Knative Eventing集群内访问broker，所以必须在集群内创建一个pod来执行`curl`命令作为事件生产者。 用以下命令创建pod： ```bash kubectl -n event-example apply -f - << EOF apiVersion: v1 kind: Pod metadata: labels: run: curl name: curl spec: containers: # This could be any image that we can SSH into and has curl. - image: radial/busyboxplus:curl imagePullPolicy: IfNotPresent name: curl resources: {} stdin: true terminationMessagePath: /dev/termination-log terminationMessagePolicy: File tty: true EOF ``` ### **给broker发送事件** - 进入刚刚创建的容器内： ```bash kubectl -n event-example attach curl -it ``` - 这里构建三种请求来展示可以发送的各种类型的事件： - 构建`type`为`greeting`的事件： ```bash curl -v "http://broker-ingress.knative-eventing.svc.cluster.local/event-example/default" \ -X POST \ -H "Ce-Id: say-hello" \ -H "Ce-Specversion: 1.0" \ -H "Ce-Type: greeting" \ -H "Ce-Source: not-sendoff" \ -H "Content-Type: application/json" \ -d '{"msg":"Hello Knative!"}' ``` 当broker接收到该事件时，`hello-display`会被激活并将事件发送给对应事件消费者。如果接收到了事件，则会收到如下类似`202 Accepted`的回应： ```bash < HTTP/1.1 202 Accepted < Date: Wed, 02 Jun 2021 08:35:12 GMT < Content-Length: 0 ``` - 构建`source`为`sendoff`的事件： ```bash curl -v "http://broker-ingress.knative-eventing.svc.cluster.local/event-example/default" \ -X POST \ -H "Ce-Id: say-goodbye" \ -H "Ce-Specversion: 1.0" \ -H "Ce-Type: not-greeting" \ -H "Ce-Source: sendoff" \ -H "Content-Type: application/json" \ -d '{"msg":"Goodbye Knative!"}' ``` 当broker接收到该事件时，`goodbye-display`会被激活并将事件发送给对应事件消费者。如果接收到了事件，则会收到如下类似`202 Accepted`的回应： ```bash < HTTP/1.1 202 Accepted < Date: Wed, 02 Jun 2021 08:42:02 GMT < Content-Length: 0 ``` - 构建包含`type`为`greeting`、`source`为`sendoff`的事件： ```bash curl -v "http://broker-ingress.knative-eventing.svc.cluster.local/event-example/default" \ -X POST \ -H "Ce-Id: say-hello-goodbye" \ -H "Ce-Specversion: 1.0" \ -H "Ce-Type: greeting" \ -H "Ce-Source: sendoff" \ -H "Content-Type: application/json" \ -d '{"msg":"Hello Knative! Goodbye Knative!"}' ``` 当broker接收到该事件时，`hello-display`和`goodbye-display`都会被激活并将事件发送给对应事件消费者。如果接收到了事件，则会收到如下类似`202 Accepted`的回应： ```bash < HTTP/1.1 202 Accepted < Date: Wed, 02 Jun 2021 08:45:16 GMT < Content-Length: 0 ``` - 使用`exit`命令退出容器。 到这里我们发送了两个事件给`hello-display`事件消费者，两个事件给`goodbye-display`。后面让我们确认正确接收了这些事件。 ### **确认事件接收** 确认事件被正确的订阅者接收了。 - 查看`hello-display`事件消费者的日志： ```bash kubectl -n event-example logs -l app=hello-display --tail=100 ``` 可以看到发送给`hello-display`的事件的`Attributes`和`Data`： ```http ☁️ cloudevents.Event Context Attributes, specversion: 1.0 type: greeting source: not-sendoff id: say-hello datacontenttype: application/json Extensions, knativearrivaltime: 2021-06-02T08:35:12.137155445Z Data, { "msg": "Hello Knative!" } ☁️ cloudevents.Event Context Attributes, specversion: 1.0 type: greeting source: sendoff id: say-hello-goodbye datacontenttype: application/json Extensions, knativearrivaltime: 2021-06-02T08:45:16.087732995Z Data, { "msg": "Hello Knative! Goodbye Knative!" } ``` - 查看`goodbye-display`事件消费者的日志： ```bash kubectl -n event-example logs -l app=goodbye-display --tail=100 ``` 可以看到发送给`goodbye-display`的事件的`Attributes`和`Data`： ```http ☁️ cloudevents.Event Context Attributes, specversion: 1.0 type: not-greeting source: sendoff id: say-goodbye datacontenttype: application/json Extensions, knativearrivaltime: 2021-06-02T08:42:02.227918434Z Data, { "msg": "Goodbye Knative!" } ☁️ cloudevents.Event Context Attributes, specversion: 1.0 type: greeting source: sendoff id: say-hello-goodbye datacontenttype: application/json Extensions, knativearrivaltime: 2021-06-02T08:45:16.087732995Z Data, { "msg": "Hello Knative! Goodbye Knative!" } ``` #### 参考资料 - https://knative.dev/docs/eventing/getting-started/ 打赏: 微信, 支付宝 标签: Knative 本作品采用知识共享署名-非商业性使用-相同方式共享 4.0 国际许可协议进行许可。本站myrat.top所有文章均为原创，转载请注明出处。
微信
支付宝