Fix broken URL in kubeless function call

[h-otter]

Issue Ref: #1226

Description:

First of all, thank you for the exciting project.

My kubeless is running on Kubernetes 1.21.
As a result of creating a function according to Quick Start (https://kubeless.io/docs/quick-start/), I confirmed that the function cannot be called with kubeless function call like #1226.
However, when I checked the function using kubectl proxy and curl, it was working properly.
So I guessed that there was a problem with the assembled URL in the command.

When I checked the assembled URL, it was as follows.

https://kubernetes/:http-function-port/proxy/

I fixed svc.ObjectMeta.SelfLink and svc.SelfLink to not be used because they were empty.
Then, I have confirmed that it works.

Thank you.

TODOs:

• Ready to review
• Automated Tests
• Docs

[h-otter]

Do I need to do anything else to get a review...?

[antgamdia]

Hi, I hope you can get it reviewed soon. Do you know if this change is also working in k8s versions prior to 1.21?

[h-otter]

Thank you for your comment.
I have confirmed that my patch works on Kubernetes 1.16 deployed with kubeadm.

root@sandbox:~/kubeless# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.15", GitCommit:"2adc8d7091e89b6e3ca8d048140618ec89b39369", GitTreeState:"clean", BuildDate:"2020-09-02T11:40:00Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.15", GitCommit:"2adc8d7091e89b6e3ca8d048140618ec89b39369", GitTreeState:"clean", BuildDate:"2020-09-02T11:31:21Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}
root@sandbox:~/kubeless# ./kubeless function deploy hello --runtime python3.8 --from-file test.py --handler test.hello
INFO[0000] Deploying function...                        
INFO[0000] Function hello submitted for deployment      
INFO[0000] Check the deployment status executing 'kubeless function ls hello' 
root@sandbox:~/kubeless# ./kubeless function call hello --data 'Hello world!'
Hello world!

[andresmgot]

Hi, I hope you can get it reviewed soon. Do you know if this change is also working in k8s versions prior to 1.21?

This CI is setup with Kubernetes 1.15 😅