Use Simple Message Queue (formerly MNS) to trigger a workflow-Container Service for Kubernetes(ACK)-阿里云帮助中心

Workflow Clusters can integrate with Alibaba Cloud Simple Message Queue (formerly MNS). Use Simple Message Queue (formerly MNS) as a broker to connect to a variety of event sources and trigger workflow runs based on events. When a new event occurs, such as an Object Storage Service (OSS) event or an EventBridge event, Simple Message Queue (formerly MNS) receives the corresponding message. Argo automatically triggers the workflow run based on the trigger conditions, which automates workflow processing.

Prerequisites

Activate the following services and features.
- Enable the event-driven feature
- Simple Message Queue (formerly MNS): Activation and permissions. This feature incurs charges for Simple Message Queue (formerly MNS). For billing details, see Billing.
Create a workflow cluster and download the Alibaba Cloud Argo CLI.

Step 1: Create an event bus

An event bus can be shared by event-driven workflows in a namespace. You can create an event bus by using NATS or Simple Message Queue (formerly MNS). If an event bus already exists, proceed directly to Step 2: Create an event source.

Create by using NATS

Create an event-bus.yaml file. Sample configuration:

apiVersion: argoproj.io/v1alpha1
kind: EventBus
metadata:
  name: default
spec:
  nats:
    native:
      replicas: 3
      auth: token

Run the following command to create the EventBus:
```
kubectl apply -f event-bus.yaml
```
Note
After the command succeeds, an EventBus pod is created in the default namespace. Subsequent operations must be performed in the same namespace.
Run the following command to verify that the EventBus pod has started:
```
kubectl get pod
```

Create by using Simple Message Queue (formerly MNS)

Log on to the SMQ console.
On the Topics page, create a topic named argoeventbus. Then, on the Topic Details page, obtain the endpoint from the Access Point section.
Log on to the RAM console as a RAM administrator.
Create a Resource Access Management (RAM) user, grant the AliyunMNSFullAccess permission to the RAM user, and obtain the RAM user's AccessKey ID and AccessKey secret.
For more information, see Create a RAM user, Manage RAM user permissions, Create an AccessKey, and View RAM user AccessKey information.

Run the following command to create a Secret for storing the AccessKey ID and AccessKey secret.

kubectl create secret generic mns-secret\
  --from-literal=accesskey=*** \
  --from-literal=secretkey=***

Create an event-bus-mns.yaml file and replace the parameters in the example with the values for your environment.

topic: Replace the value with the name of the topic created in step 2 of Simple Message Queue (formerly MNS).
endpoint: Replace the value with the endpoint obtained in step 2.

apiVersion: argoproj.io/v1alpha1
kind: EventBus
metadata:
  name: default
spec:
  alimns:
    accessKey:
      key: accesskey
      name: mns-secret
    secretKey:
      key: secretkey
      name: mns-secret
    topic: argoeventbus  # The name of the topic in Simple Message Queue (formerly MNS).
    endpoint: http://165***368.mns.<region>.aliyuncs.com  # The endpoint of Simple Message Queue (formerly MNS).

Run the following command to apply the event-bus-mns.yaml file and create the event bus resource.
```
kubectl apply -f event-bus-mns.yaml
```

Step 2: Create an event source

Log on to the SMQ console.
On the Queues page, create a queue named test-event-queue. Then, on the Queue Details page, obtain the endpoint from the Access Point section.
Note
If you created the event bus by using Simple Message Queue (formerly MNS), you can skip steps 3 through 5 and proceed directly to step 6.
Log on to the RAM console as a RAM administrator.
Create a Resource Access Management (RAM) user, grant the AliyunMNSFullAccess permission to the RAM user, and obtain the RAM user's AccessKey ID and AccessKey secret.
For more information, see Create a RAM user, Manage RAM user permissions, Create an AccessKey, and View RAM user AccessKey information.

Run the following command to create a Secret for storing the AccessKey ID and AccessKey secret.

kubectl create secret generic mns-secret\
  --from-literal=accesskey=*** \
  --from-literal=secretkey=***

Create an event-source.yaml file and replace the parameters in the example with the values for your environment.

topic: Replace the value with the name of the topic created in step 2 of Simple Message Queue (formerly MNS).
endpoint: Replace the value with the endpoint obtained in step 2.

apiVersion: argoproj.io/v1alpha1
kind: EventSource
metadata:
  name: ali-mns
spec:
  mns:
    example:
      jsonBody: true
      accessKey:
        key: accesskey
        name: mns-secret
      secretKey:
        key: secretkey
        name: mns-secret
      queue: test-event-queue # The name of the queue in Simple Message Queue (formerly MNS).
      waitTimeSeconds: 20
      endpoint: http://165***368.mns.<region>.aliyuncs.com # The endpoint of Simple Message Queue (formerly MNS).

Run the following command to apply the event-source.yaml file and create the event source.
```
kubectl apply -f event-source.yaml
```
Run the following command to check whether the event source Pod starts as expected.
```
kubectl get pod
```

Step 3: Create an event sensor

Create an event-sensor.yaml file and embed the workflow definition to run in the event sensor. The following sample code shows the event sensor configuration:

View the sample code

apiVersion: argoproj.io/v1alpha1
kind: Sensor
metadata:
  name: ali-mns
spec:
  template:
    serviceAccountName: default
  dependencies:
    - name: test-dep
      eventSourceName: ali-mns    # Matches the event source name.
      eventName: example          # Matches the event name defined in the event source.
  triggers:
    - template:
        name: mns-workflow
        k8s:
          operation: create
          source:
            resource:
              apiVersion: argoproj.io/v1alpha1    # Embeds the workflow definition.
              kind: Workflow
              metadata:
                generateName: ali-mns-workflow-
              spec:
                entrypoint: whalesay
                arguments:
                  parameters:        # Parameters pass the event content.
                    - name: message
                      # this is the value that should be overridden
                      value: hello world
                templates:
                  - name: whalesay
                    inputs:
                      parameters:
                        - name: message
                    container:
                      image: docker/whalesay:latest
                      command: [cowsay]
                      args: ["{{inputs.parameters.message}}"]
          parameters:
            - src:        # Parses the event content and passes it to the workflow.
                dependencyName: test-dep
                dataKey: body
              dest: spec.arguments.parameters.0.value

Apply the event-sensor.yaml file to create the event sensor.
```
kubectl apply -f event-sensor.yaml
```
Check whether the event sensor Pod starts as expected.
```
kubectl get pod
```

Note

When you create an event bus by using Simple Message Queue (formerly MNS), a corresponding Simple Message Queue (formerly MNS) queue is automatically created after the event sensor is created. The queue name uses the following format: ackone-argowf-<namespace>-<sensor-name>-<sensor-uid>.

Step 4: Verify that sending a message to Simple Message Queue (formerly MNS) triggers the workflow

Log on to the SMQ console.
On the Queues page, find the queue named test-event-queue. In the Actions column, click Send Messages.
On the quick-start page for sending and receiving messages, enter test trigger argo workflow as the message content and then click Send Message.

View the workflow run in the workflow cluster.

argo list

The expected output is as follows:

NAME                     STATUS    AGE   DURATION   PRIORITY
ali-mns-workflow-5prz7   Running   6s    6s         0

Obtain the workflow logs to view the message content.

argo logs ali-mns-workflow-5prz7

Important

The workflow name in this command must match the name returned in the previous step. ali-mns-workflow-5prz7 is only an example value. Replace it with the value returned in your environment.
The message content is Base64-encoded.

The expected output is as follows:

ali-mns-workflow-5prz7-whalesay-2429203954: time="2023-12-14T08:33:37.964Z" level=info msg="capturing logs" argo=true
ali-mns-workflow-5prz7-whalesay-2429203954:
ali-mns-workflow-5prz7-whalesay-2429203954:  < dGVzdCB0cmlnZ2VyIGFyZ28gd29ya2Zsb3c= >
ali-mns-workflow-5prz7-whalesay-2429203954:  -----------------------------------------
ali-mns-workflow-5prz7-whalesay-2429203954:     \
ali-mns-workflow-5prz7-whalesay-2429203954:      \
ali-mns-workflow-5prz7-whalesay-2429203954:       \
ali-mns-workflow-5prz7-whalesay-2429203954:                     ##        .
ali-mns-workflow-5prz7-whalesay-2429203954:               ## ## ##       ==
ali-mns-workflow-5prz7-whalesay-2429203954:            ## ## ## ##      ===
ali-mns-workflow-5prz7-whalesay-2429203954:        /""""""""""""""""___/ ===
ali-mns-workflow-5prz7-whalesay-2429203954:   ~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ /  ===- ~~~
ali-mns-workflow-5prz7-whalesay-2429203954:        \______ o          __/
ali-mns-workflow-5prz7-whalesay-2429203954:         \    \        __/
ali-mns-workflow-5prz7-whalesay-2429203954:           \____\______/
ali-mns-workflow-5prz7-whalesay-2429203954: time="2023-12-14T08:33:38.979Z" level=info msg="sub-process exited" argo=true error="<nil>"

Step 5: Delete event-related resources

Delete the related resources.
- Delete the event sensor.
```
kubectl delete sensor ali-mns
```
- Delete the event source.
```
kubectl delete eventsource ali-mns
```
- Delete the event bus.
```
kubectl delete eventbus default
```
Check the Pod status to confirm that all resources have been deleted.
```
kubectl get pod
```