After updating k8s ingress(backend) multiple times, the EventUpdate event always exists and cannot end

[hahayyum]

Issue description

Ingress:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: apisix
  name: ccdd
  namespace: 3-default-ns
spec:
  rules:
    - http:
        paths:
          - backend:
              serviceName: deployment-lerxr7
              servicePort: 16629
            path: /adc
            pathType: Prefix
          - backend:
              serviceName: deployment-lerxr7
              servicePort: 18889
            path: /dede
            pathType: Prefix

first update:

16629->16639 , Port 16639 is not configured in the actual service
erro info: failed to translate ingress {"event": "update", "error": "service.spec.ports: port not defined", "ingress": {}}
The first update event keeps looping
code:
ing, err = c.controller.ingressLister.V1beta1(namespace, name)
..........
tctx, err := c.controller.translator.TranslateIngress(ing) ---Check the latest ingress

second update
16639->16629
erro info: failed to translate ingress {"event": "update", "error": "service.spec.ports: port not defined", "ingress": {}}
End of first update event. The second update event keeps looping
code
oldCtx, err := c.controller.translator.TranslateIngress(ingEv.OldObject) --Always verify old ingress

I think in the update event, there is no need to verify the backend.service in the old ingress, or just delete it if there is a problem (du)

Environment

k8s: 1.19.6
apisix: 2.7
apisix-ingress-controller: 1.2.0

Minimal test code / Steps to reproduce

see description

Actual result

see description

Error log

see description

Expected result

When the port is re-updated correctly, the second update event ends

[tao12345666333]

apisix-ingress-controller: 1.2.0 is too old, please upgrade to latest version v1.4.1.

In the new version, some invalid events will be removed from the work queue.

[hahayyum]

@tao12345666333
After verification, the latest 1.4.1 version problem still exists
The relevant code logic has not been modified

error info 1:
ingress/ingress.go:131 failed to translate ingress {"error": "service.spec.ports: port not defined", "ingress": {}}

error info 2:
ingress/ingress.go:166 failed to translate ingress {"event": "update", "error": "service.spec.ports: port not defined", "ingress": {}}

[tao12345666333]

sorry i remembered wrong.

There was some handling in #893, but it wasn't introduced in v1.4.1.
Can you test with the latest code from the master branch?

[hahayyum]

@tao12345666333
After verification, the master version problem still exists.
Can I try to fix it?

[tao12345666333]

@hahayyum yes, please! Assigned to you

Thanks

[tao12345666333]

#1040 has been merged. I will close this one. Thanks