nginx-ingress-controller doesn't respect x509/subjectAltName

[roobert]

To reproduce, create an SSL certificate with alternate for the following:

• host1.example.com
• host2.example.com

Set the CN to host1.example.com.

Now try and use the certificate with one of the alternate names, e.g:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: test-ingress
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  tls:
    - secretName: certificate-with-altnames
      hosts:
        - host1.example.com
        - host2.example.com

  rules:
    # host1.example.com is value of CN, and one of the alternative names
    - host: host1.example.com
      http:
        paths:
        - path: /
          backend:
            serviceName: test-backend
            servicePort: 8080

    # host2.example.com is one of the subjectAltName's
    - host: host2.example.com
      http:
        paths:
        - path: /
          backend:
            serviceName: test-backend
            servicePort: 8080

In this scenario the controller does not recognise the certificate as valid for host2.example.com and instead prints out the following error:

[...] ssl certificate default/certificate-with-altnames does not contain a common name for host host2.example.com

[aledbf]

@roobert right now we are not reading subjectAltName's, only CommonName

[aledbf]

Closing. Duplicate of #548

[aledbf]

@roobert please check if the image quay.io/aledbf/nginx-ingress-controller:0.147 solves the issue