Get started

go-chassis can be integrated with Istio for service discovery and routing. To enable Istio pilot support in go-chassis, the simple 2 steps are needed during development:

• Import the istiov2 registry plugin from mesher

import _ "github.com/go-mesh/mesher/plugins/registry/istiov2"

This will install the istiov2 service discovery plugin at runtime.

• Configure service discovery in chassis.yaml

cse:
  service:
    registry:
      registrator:
        disabled: true
      serviceDiscovery:
        type: pilotv2
        address: grpc://istio-pilot.istio-system:15010

Disable the registrator(since we don’t have to register the service to Pilot explicitly) and change serviceDiscovery type to pilotv2(indicates the Pilot that provides xDS v2 API, the xDS v1 API is already deprecated), configure the address, typically istio-pilot.istio-sytem:15010 in a Istio environment.

Then when deploying the micro services in Istio, make sure the Kubernetes Services’ name and go-chassis service name is exactly the same, then go-chassis will discovery the service instances as expected from Pilot.

The routing tags in Istio

In the original go-chassis configuration, user can specify tag based route rules, as described below:

## router.yaml
router:
  infra: cse
routeRule:
  targetService:
    - precedence: 2
      route:
      - tags:
          version: v1
        weight: 40
      - tags:
          version: v2
          debug: true
        weight: 40
      - tags:
          version: v3
        weight: 20

Then in a typical Istio environment, which is likely to be Kubernetes cluster, user can specify the DestinationRules for targetService with the same tags:

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: targetService
spec:
  host: targetService
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
      debug: "true"
  - name: v3
    labels:
      version: v3

Notice that the subsets’ tags are the same with those in router.yaml, then go-chassis’s tag based load balancing strategy works as it originally does.