priority.md

Priority of route rules

If a request matches multiple ingress rules, BFE Ingress Controller will decide which rule will be hit according to below strategies:

• Compare the hostname and select the rule with most precise hostname;
• If more than one rule is selected in the above step, select the rule with most precise path;
• If more than one rule is selected in the above step, select the rule with most advanced conditions;
• If more than one rule is selected in the above step, select the rule which matches an advanced condition of higher priority
  • in advanced condition, Cookie condition has higher priority than Header condition；

Examples

Hostname precision first

kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "host_priority1"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service1
              servicePort: 80
---
kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "host_priority2"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
spec:
  rules:
    - host: *.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service2
              servicePort: 80

In above example, for requests generated by curl "http://example.net/bar", the rule in ingress host_priority1 will be hit.

Path precision first when hostname are identical

kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "path_priority1"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar/foo
            backend:
              serviceName: service1
              servicePort: 80
---
kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "path_priority2"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
    bfe.ingress.kubernetes.io/router.header: "key: value"
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service2
              servicePort: 80

In above example, for requests generated by curl "http://example.net/bar/foo" -H "Key: value", the rule in ingress path_priority1 will be hit

More advanced condition first, when hostname and path both identical

kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "cond_priority1"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
    bfe.ingress.kubernetes.io/router.header: "key: value"
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service1
              servicePort: 80
---
kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "cond_priority2"
  namespace: production  
  annotations:
    kubernetes.io/ingress.class: bfe 
  
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service2
              servicePort: 80

In above example, for requests generated by curl "http://example.net/bar/foo" -H "Key: value", the rule in ingress cond_priority1 will be hit

Matched advanced condition with higher priority first, when multiple rules meet above criteria

kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "multi_cond_priority1"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
    bfe.ingress.kubernetes.io/router.header: "header-key: value"
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service1
              servicePort: 80
---
kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: "multi_cond_priority2"
  namespace: production
  annotations:
    kubernetes.io/ingress.class: bfe 
    bfe.ingress.kubernetes.io/router.cookie: "cookie-key: value"
spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service2
              servicePort: 80

In above example, for requests generated by curl "http://example.net/bar/foo" -H "Header-key: value" --cookie "cookie-key: value", the rule in ingress multi_cond_priority2 will be hit, because Cookie condition has higher priority than Header condition.