Alibaba Cloud Service Mesh:Label traffic

Field description

This section describes the CRD fields in an ASM instance of version 1.17 or later.

Spec

WorkloadSelector

TrafficLabelRule

Label

valueFrom

The valueFrom field supports the following four variables. You can click the corresponding expand icons below the table to view the descriptions of the variables.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: productpage-v1
  labels:
    app: productpage
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: productpage
      version: v1
  template:
    metadata:
      annotations:
        sidecar.istio.io/logLevel: debug
      labels:
        app: productpage
        version: v1
        ASM_TRAFFIC_TAG: test
    spec:
      serviceAccountName: bookinfo-productpage
      containers:
      - name: productpage
        image: docker.io/istio/examples-bookinfo-productpage-v1:1.16.2
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
        volumeMounts:
        - name: tmp
          mountPath: /tmp
      volumes:
      - name: tmp
        emptyDir: {}

Configuration examples

In the following examples, the ASM instances are of version 1.17 or later. For more information about how to update an ASM instance, see Update an ASM instance.

Example 1: Label traffic for a workload

You can define workloadSelector to select the workload based on the label and then label the traffic of the workloads in a namespace.

1. Deploy the Bookinfo application. For more information, see Deploy an application in an ASM instance.

2. Create a file named productpage-trafficlabel.yaml and copy the following content to the file:

   apiVersion: istio.alibabacloud.com/v1
   kind: TrafficLabel
   metadata:
     name: productpage
     namespace: default
   spec:
     workloadSelector:
       labels:
         app: productpage
     rules:
     - labels:
         - name: asm-labels-test-a
           valueFrom:
           - $getExternalInboundRequestHeader(header1, x-request-id)
           - $getLabel(header2)

3. Run the following command to label the traffic of the productpage workload:

    kubectl apply -n default  -f productpage-trafficlabel.yaml

4. Run the following command to view the proxy configuration of the productpage workload:

   kubectl exec -it -n default deploy/productpage-v1 -c istio-proxy -- curl localhost:15000/config_dump

   Expected output:

   {
                 "name": "com.aliyun.traffic_label",
                 "typed_config": {
                  "@type": "type.googleapis.com/envoy.config.filter.traffic_label.v3alpha.TrafficLabel",
                  
                 }
                },

   You can see the preceding filter configuration in type.googleapis.com/envoy.config.listener.v3.Listener/envoy.filters.network.http_connection_manager/http_filters under Listener Config (type.googleapis.com/envoy.admin.v3.ListenersConfigDump) or dynamic_listeners. This indicates that the traffic label is configured.

5. Run the following command to view the proxy configurations of other workloads, such as the details pod:

   kubectl exec -it -n default deploy/details-v1 -c istio-proxy -- curl localhost:15000/config_dump |grep type.googleapis.com/envoy.config.filter.traffic_label.v3alpha.TrafficLabel

   The returned result is empty, indicating that no relevant filter is available. The result meets expectations.

Example 2: Label traffic at the namespace level

If you leave the workloadSelector field empty, the label is added to the traffic of all workloads in the namespace. The following example labels the traffic of all workloads in the default namespace.

1. Create a file named all-workload-for-ns-trafficlabel.yaml and copy the following content to the file:

   apiVersion: istio.alibabacloud.com/v1
   kind: TrafficLabel
   metadata:
     name: all-workload-for-ns
     namespace: default
   spec:
     rules:
     - labels:
         - name: asm-labels-test-b
           valueFrom:
           - $getExternalInboundRequestHeader(header1, x-request-id)
           - $getLabel(header2)

2. Run the following command to label the traffic of all workloads in the default namespace:

    kubectl apply -n default -f all-workload-for-ns-trafficlabel.yaml

3. Run the following command to view the proxy configurations of a workload, such as the details pod:

   kubectl exec -it -n default deploy/details-v1 -c istio-proxy -- curl localhost:15000/config_dump |grep type.googleapis.com/envoy.config.filter.traffic_label.v3alpha.TrafficLabel

   Expected output:

    "@type": "type.googleapis.com/envoy.config.filter.traffic_label.v3alpha.TrafficLabel",

   The preceding output indicates that the traffic label is configured.