Mapping ExternalNames to custom ports

[gildas]

What does this PR do?

This fixes issue #1816

Basically, if the servicePort.Port is not 443 or 80, we add it to the url (not the name).
And if the servicePort.name is "https" we also use "https" as the protocol. That allows to proxy https traffic to any port.

Motivation

In my deployment, I need træfik to proxy to external servers on custom ports. I do not control these servers.

More

• Added/updated tests
• Added/updated documentation

[gildas]

Actually, there is an issue with this PR.

When defining the Kubernetes Service, each port must have a different name.
That means if the current PR, we could have only https-type port (outside of 443).

In other words, we cannot declare:

apiVersion: v1
kind: Service
metadata:
  name: myservice
spec:
  type: ExternalName
  externalName: myserver.acme.com
  ports:
    - name: https
      port: 8443
    - name: https
      port: 9090

Kubernetes will choke on the second port upon creation.

How about we use the following naming convention:

  ports:
    - name: https
      port: 8443
    - name: https-icws
      port: 9090

The code would instead of comparing port.Name to "https" would compare the beginning of port.Name to "https".

What do you guys think?

[emilevauge]

WDYT @containous/kubernetes ?

[dtomcej]

I can get behind checking to see if the port name has an https prefix. I can't think of any reason this should not be allowed.

👍

[gildas]

It would also be very easy to change the PR from (https://github.com/gildas/traefik/blob/83629789f5a7eed8f13ff0715983efd16ce73a30/provider/kubernetes/kubernetes.go#L273):

	if port.Port == 443 || port.Name == "https" 

to:

	if port.Port == 443 || strings.HasPrefix(port.Name, "https") 

[dtomcej]

LGTM

[dtomcej]

ping @timoreimann

[nmengin]

LGTM

[m3co-code]

LGTM, thanks for the feature! 👍

[billimek]

This is merged to master but still doesn't appear to be in any of the traefik releases. What is the typical path forward to get something like this included in a release?

[timoreimann]

@billimek the milestone indicates that the PR will be part of Traefik 1.7. Thus, the next release will include the feature.