This blog is to demo how to use TSM traffic management policy to achieve “canary” or incrementally release a new version of deployment.

(0) Environment

1. A TKGs cluster running on M18v2 SDDC
2. The said TKGs cluster had onboarded on Tanzu Service Mesh (v5.04)
3. Deploy the Istio demo application: bookinfo. You can refer to the link for more information about the application.
4. Global name space called bookinfo created. The associated domain is intranet.vmconaws.net

(1) Bookinfo PODs and services

dzhang@david-ubuntu01:~$ k get pod
NAME                            READY   STATUS    RESTARTS   AGE
details-v1-75b6944bb9-pz5fj     2/2     Running   0          150m
productpage-v1-9fff55d4-bkhgr   2/2     Running   0          150m
ratings-v1-56d454b5b6-28f25     2/2     Running   0          150m
reviews-v1-5c76cff476-q7tjp     2/2     Running   0          150m
reviews-v2-7f86c797f6-mkfwh     2/2     Running   0          150m
reviews-v3-64ddc56888-nf5jg     2/2     Running   0          150m

dzhang@david-ubuntu01:~$ k get svc
NAME          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
details       ClusterIP   10.96.87.108    <none>        9080/TCP   150m
kubernetes    ClusterIP   10.96.0.1       <none>        443/TCP    6d18h
productpage   ClusterIP   10.96.199.199   <none>        9080/TCP   150m
ratings       ClusterIP   10.96.133.121   <none>        9080/TCP   150m
reviews       ClusterIP   10.96.49.244    <none>        9080/TCP   150m
supervisor    ClusterIP   None            <none>        6443/TCP   6d18h

(2) Traffic Management

As our current review service is running at v2. We are going to upgrade the review service from v2 to v3. What we did here is sending 90% traffic still to v2 but 10% traffic to v3. Once we are happy with v3, we can gradually move more and more application traffic to v3.

By use of an API, i created a traffic management policy to achieve what we desire.

PUT[<https://prod-2.nsxservicemesh.vmware.com/tsm/v1alpha2/project/default/global-namespaces/{{gns}>](<https://prod-2.nsxservicemesh.vmware.com/tsm/v1alpha2/project/default/global-namespaces/%7B%7Bgns%7D>)}/traffic-routing-policies/{{tm-policy}}

{
    "description": "policy to split 90% of traffic to version 2 and 10% of traffic to version 3",
    "service": "reviews",
    "traffic_policy": {
        "http": [
            {
                "targets": [
                    {
                        "service_version": "v2",
                        "weight": 90
                    },
                    {
                        "service_version": "v3",
                        "weight": 10
                    }
                ]
            }
        ]
    },
    "id": "tm-policy1"
}

We can see the corresponding Istio virtual service was updated.

dzhang@david-ubuntu01:~/bookinfo$ k get vs nsxsm.gns.bookinfo.reviews -o yaml
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  creationTimestamp: "2022-05-20T03:54:17Z"
  generation: 3
  labels:
    createdby: allspark
    gns: bookinfo
    routing-policy-id: tm-policy1
  name: nsxsm.gns.bookinfo.reviews
  namespace: default
  resourceVersion: "2980900"
  uid: 4d532c4c-3f1c-4e7c-96b2-d86efc0e50c3
spec:
  exportTo:
  - .
  hosts:
  - reviews.intranet.vmconaws.net
  - reviews.default.svc.cluster.local
  - 251.11.204.141
  http:
  - headers:
      request:
        add:
          x-allspark-request-header: vmc-tanzu-c001
    route:
    - destination:
        host: v2.reviews.intranet.vmconaws.net
      weight: 90
    - destination:
        host: v3.reviews.intranet.vmconaws.net
      weight: 10

# Please note that we dont use subset here.
# nsxsm.gns.bookinfo.reviews                              ["reviews.intranet.vmconaws.net","reviews.default.svc.cluster.local","251.11.204.141"]

Let us send some traffic to test the traffic management policy. You can see that ~90% traffic were sent to v2 review service and ~10 traffic were sent to the new version of review service.

Assuming that we are quite happy with v3, we can change the traffic management policy to send 90% traffic to v3 and 10% traffic to v2.

{
    "description": "policy to split 10% of traffic to version 2 and 90% of traffic to version 3",
    "service": "reviews",
    "traffic_policy": {
        "http": [
            {
                "targets": [
                    {
                        "service_version": "v2",
                        "weight": 10
                    },
                    {
                        "service_version": "v3",
                        "weight": 90
                    }
                ]
            }
        ]
    },
    "id": "tm-policy1"
}