traffic-split

This guide describes how to use the traffic-split plugin in APISIX Ingress.

The traffic-split plugin can be used to dynamically route part of traffic to various upstream services.

IMPORTANT

If multiple services are declared in ApisixRoute http[].backends, it cannot be used with traffic-split.

Correct example:

apiVersion: apisix.apache.org/v2
kind: ApisixRoute
metadata:
  name: httpbin-route
spec:
  http:
    - name: rule1
      match:
        paths:
          - /*
      backends:
      - serviceName: httpbin
        servicePort: 80 
      plugins:
      - name: traffic-split # It works.
        enable: true

Invalid examples:

apiVersion: apisix.apache.org/v2
kind: ApisixRoute
metadata:
  name: httpbin-route
spec:
  http:
    - name: rule1
      match:
        paths:
          - /*
      backends:
      - serviceName: httpbin1
        servicePort: 80 
      - serviceName: httpbin2
        servicePort: 80
      plugins:
      - name: traffic-split # Not working, this plugin is invalid and cannot be used with multiple backend.
        enable: true

Example-usage

IMPORTANT

The traffic-split plugin will directly use Kubernetes DNS, which will not automatically resolve services.

Because there is namespace isolation between services, and use the form of ${service}.${namespace} in the upstream.nodes.

Deploy hecho1 and hecho2 service

We use hashicorp/http-echo as the service image, See its overview page for details.

Deploy it to the default namespace:

# deployment hecho1
kubectl run hecho1 --image hashicorp/http-echo --port 5678 -- -text "http-echo v1"
kubectl expose pod hecho1 --port 5678

# deployment hecho2
kubectl run hecho2 --image hashicorp/http-echo --port 5678 -- -text "http-echo v2"
kubectl expose pod hecho2 --port 5678

Route the traffic

Routes to different services according to the http header subset.

• If HTTP header subset: v1 routing to hecho1.
• If HTTP header subset: v2 routing to hecho2.

apiVersion: apisix.apache.org/v2
kind: ApisixRoute
metadata:
  name: httpbin-route
spec:
  http:
    - name: rule1
      match:
        paths:
          - /hecho
      backends:
        - serviceName: hecho1
          servicePort: 5678
      plugins:
        - name: traffic-split
          enable: true
          config:
            rules:
              - match:
                  - vars:
                      - - http_subset
                        - ==
                        - v1
                weighted_upstreams:
                  - upstream:
                      name: v1
                      type: roundrobin
                      nodes:
                        hecho1.default:5678: 1
              - match:
                  - vars:
                      - - http_subset
                        - ==
                        - v2
                weighted_upstreams:
                  - upstream:
                      name: v2
                      type: roundrobin
                      nodes:
                        hecho2.default:5678: 1

Use header sebset: v1 to access:

kubectl run -it --rm curl --restart=Never --image=curlimages/curl -- \
  curl http://apisix-gateway.ingress-apisix/hecho -H 'subset: v1' -i

It should output:

HTTP/1.1 200 OK
Content-Type: text/plain; charset=utf-8
Content-Length: 11
Connection: keep-alive
X-App-Name: http-echo
X-App-Version: 0.2.3
Date: Tue, 28 Feb 2023 08:54:31 GMT
Server: APISIX/3.1.0

http-echo v1

Use header sebset: v2 to access:

kubectl run -it --rm curl --restart=Never --image=curlimages/curl -- \
  curl http://apisix-gateway.ingress-apisix/hecho -H 'subset: v2' -i

It should output:

HTTP/1.1 200 OK
Content-Type: text/plain; charset=utf-8
Content-Length: 11
Connection: keep-alive
X-App-Name: http-echo
X-App-Version: 0.2.3
Date: Tue, 28 Feb 2023 08:55:04 GMT
Server: APISIX/3.1.0

http-echo v2